The Book on Radiant Heating: When it makes sense and when it might not

June 3rd, 2013

Alex makes some great points here, but the thing to keep in the back of your mind is that this is coming from the perspective that you are going green crazy on your house. Even if you are just building a reasonably green home, bang for your buck is definitely something to consider, give me a ring if you would like to discuss your options. -Wes

The following article was written for the Environmental Building News by Alex Wilson. Copyright © 2002 by BuildingGreen, Inc. All rights reserved; reprinted with permission. www.BuildingGreen.com

Radiant-Floor Heating: When It Does—and Doesn’t—Make Sense

During judging of the Northeast Green Building Design Competition last spring, I was struck by the number of residential entries with really stellar passive solar design and super-high-performance building envelopes. Clearly, I thought as I began reviewing the features, we’ve come a long way in high-performance residential green building since my first experience with passive solar in the mid-1970s. But something also seemed odd. A majority of these entries had sophisticated radiant-floor heating systems. After going to all the effort and expense to superinsulate the envelopes of these houses and provide passive solar design, did they still need $10,000 heating systems? And did those systems really make sense from a performance standpoint? I wasn’t sure, and decided to dig into these questions.

I’ve long been a fan of the comfort delivered by radiant-floor heat, and strong arguments are often made about energy savings and indoor air quality advantages. But is this really the best match for high-performance green homes? In the most energy-efficient buildings, the answer seems to be “no,” though radiant-floor heating can offer both comfort and IAQ benefits. This article provides a quick overview of radiant-floor heating, reviews the benefits of this heat-delivery approach, and reviews when these systems do—and do not—make sense in homes and small commercial buildings.

Radiant-Floor Heating Overview

Radiant-floor heating has its origin in ancient Rome, where fires were built beneath the floors of villas. Early Korean buildings were similarly heated by channeling flue gases beneath floors before venting those gases up through chimneys. Frank Lloyd Wright piped hot water, rather than air, through the floors of many of his buildings in the 1930s—a practice that has become common in custom homes today.

Radiant-floor heating turns a floor into a large-area, low-temperature radiator. In most modern radiant-floor heating systems, warm water circulates through plastic tubing either embedded in a floor slab or attached to the underside of subflooring. With slab systems, one can use either a standard concrete slab-on-grade, or a thinner, lightweight gypsum-concrete slab poured on a subfloor or over an existing finished floor. In either case, the thermal mass of the slab holds heat and radiates it slowly to the living space above.

In addition to hot water as the heat source, radiant floors can also use electricity or hot air. Due to the high cost of electricity in most areas, radiant-electric floor heating usually makes the most sense when off-peak electricity is available for charging a slab at night and during other off-peak hours. Production of electromagnetic fields (EMFs) is also a potential concern with radiant electric heating (see EBN Vol. 3, No. 2). Radiant-air floors are occasionally used in commercial buildings but are generally impractical and too expensive for residential applications.

For hydronic radiant-floor systems, copper piping has been used in the past, but most systems today use either rubber or cross-linked polyethylene (PEX) tubing—the latter being by far the most common. Design of radiant-floor heating systems is quite complex and should be done by someone with adequate training or experience. Various design manuals, manufacturer-specific installation guides, and software tools are available for use in designing and sizing radiant-floor heating systems. The length of tubing required per square foot of floor depends on such variables as tubing diameter, type of radiant-floor system (thick slab, thin slab, no slab), climate, heat load of the building, and type of boiler and controls used. Manufacturers have done a great job in recent years in packaging the various components to simplify the design of radiant-floor systems.

A key requirement for most radiant-floor heating systems is adequate insulation beneath the heated slab or beneath the tubing (when tubing is attached to the underside of a subfloor). Most manufacturers recommend a minimum of 1” (25 mm) of extruded polystyrene (XPS) for concrete slab-on-grade radiant heating systems, but significantly higher levels are justified in cold climates.

Zoning of radiant floors is usually done with advanced manifold modules that allow the water temperature to be varied in different zones. This provides flexibility for maintaining different temperatures in different rooms and for allowing differential heat delivery to spaces with and without solar gain.

Finally, sophisticated controls are often installed to ensure optimal comfort and to maximize energy performance. Some radiant-floor systems rely on separate temperature sensors outdoors, within the floor slab, and in the living space—with microprocessor control to regulate just when and where hot water should be delivered. Because of the long lag-time with concrete-slab radiant-floor heating systems, standard set-back thermostats usually are not effective, though set-back thermostats that have a built-in anticipation feature may work well for this application, says building consultant Andy Shapiro, of Montpelier, Vermont.

Benefits of Radiant-Floor Heating

Radiant-floor heating offers a number of significant benefits:

Comfort. By far, the biggest selling point for radiant-floor heating is comfort. The large radiant surface means that most of the heat will be delivered by radiation—heating occupants directly—rather than by convection (the primary mechanism of heat delivery from conventional hydronic baseboard “radiators”). Warmer surfaces in a living space result in a higher mean radiant temperature, a measure of surface temperatures in a space that influences the rate of radiant heat loss from occupants). With higher mean radiant temperatures, most people are comfortable even at lower air temperatures. Delivery of the heat at floor level with a warm floor surface also allows occupants to walk around barefoot even in winter—a very popular feature. Enhanced comfort should be a big selling point in any green home, so a strong case can be made for this heating approach.

“Until you’re lived with this form of heat,” says Radiant Panel Association executive director Larry Drake (who got involved with radiant heating after years of working with solar houses), “it’s hard to understand how comfortable it is.” He argues that with green homes in particular, after going to all the effort and expense to incorporate healthy and sustainable materials, ensuring high levels of comfort with radiant heat should be a top priority.

Energy savings

There is potential for saving energy with radiant-floor heating through several mechanisms, including lower thermostat settings, lower-temperature boiler settings, and reduced infiltration. Homeowners with radiant-floor heating are likely to be comfortable at lower air temperatures because of the elevated mean radiant temperature in such homes, the lack of significant airflow (as occurs with convective hydronic heating and forced-air heating systems), and the delivery of heat at floor level. Proponents of radiant-floor heating argue that someone normally comfortable at 72°F (22°C) will be comfortable in a building with radiant-floor heating kept at 68°F (20°C). If this is true, one would expect people with radiant-floor heating to keep their thermostats lower and thus realize significant energy savings.

The second opportunity for energy savings with radiant-floor heating is through keeping the boiler temperature lower than is necessary with conventional baseboard hot water distribution. The typical European approach with radiant-floor heating is to circulate fairly low-temperature water on an almost-continuous basis, varying the water temperature as needed to satisfy the load. This practice might reduce heat loss into unconditioned space if boiler and piping are located in an unheated basement, but experts EBN spoke with suggest that the savings would be very small at best—especially because of the additional electricity consumption to operate pumps for long hours. Green building consultant Marc Rosenbaum, P.E., of Meriden, New Hampshire, suggests using a low-mass boiler that is fired on-demand, rather than a high-mass boiler operated almost continuously.

The third opportunity for energy savings (over forced-air heat) is that radiant-floor systems do not increase the rate of air infiltration. Standard forced-air heating systems can significantly increase or decrease air pressure in different parts of a building, which in turn can increase air infiltration/exfiltration rates—at least in a conventional, leaky building. With radiant-floor heating, as with baseboard hydronic heating, this will not happen. (A well-designed, properly balanced forced-air system should not increase infiltration.)

Potential for use of solar energy

The relatively low temperature required for circulation water in a radiant-floor heating system provides an opportunity to utilize solar hot water. This approach works best with concrete-slab systems; higher-temperature water is generally required when the tubing is attached to the underside of wooden floors. While such systems are fairly complex and expensive, radiant slabs offer one of the best ways to make use of solar energy for heating portions of a building without direct access to sunlight. Most practical are systems in which solar energy heats water in a storage tank that can then be circulated through the slab. According to an EREN Consumer Energy Information Brief (www.eren.doe.gov) titled “Solar Radiant Floor Heating,” such systems typically cost at least $14,000. Backup heat is still required and can be provided with a wood stove, through-the-wall-vented gas heater, electric resistance heat, or backup heating element in the solar storage tank.

Increased boiler life. By operating a boiler at a lower temperature, its life can be extended. Radiant-floor heating systems typically use water temperatures of 85–140°F (30–60°C), compared with baseboard hydronic systems that typically operate at 130–160°F (55–70°C). At these operating temperatures, boiler life can exceed 45 years, according to information from DOE. (Shapiro is skeptical of this claim, however, pointing out that newer boilers are made for cold-start operation and should hold up well with this temperature cycling.)

Quiet operation

Radiant hydronic floor heating is extremely quiet. Unlike forced-air heat, there is no noise from a fan or airflow through ducts; and unlike hydronic baseboard heat, there is usually no gurgle of water through baseboard radiators or creaking from expansion and contraction. The primary noise will be the sound of circulating pumps and the fan used in power-venting the boiler. With radiant-floor systems that have tubing attached to the underside of wood flooring, there may also be some creaking from expansion and contraction.

Flexible room layout

Because there are no baseboard radiators or air registers with radiant-floor heating, there is much greater freedom as to where furniture can be placed. Radiant-floor heating systems are “invisible.”

Improved indoor air quality

An argument can be made for improved indoor air quality in houses with radiant-floor heat. Compared with a conventional forced-air distribution system, there is likely to be less dust circulated around the house. And unlike electric baseboard or forced-air heat, there will be no surfaces hot enough to burn dust particles—which could introduce volatile chemicals or toxic particulates into house air (even passing through filters). This concern would be greatest for people with acute chemical sensitivities. In fact, veteran builder Max Strickland, of Burkholder

Construction in Travers City, Michigan, first became interested in radiant-floor heating several years ago after his wife became chemically sensitive. He’s worried about “frying the air” with conventional heating systems and feels that conventional filters on forced-air systems are not effective. Strickland went on to build an American Lung Association (ALA) Health House in Travers City three years ago, and he now incorporates radiant-floor heating into all of his homes (typically 4 to 6 high-end custom houses per year).

So What’s Wrong with Radiant-Floor Heating?

In the right application, radiant-floor heating is a superb heat-delivery system—in fact, perhaps the very best. You usually pay more for it, but the enhanced comfort, potential energy savings, and other benefits can easily justify the extra cost. That said, however, super-energy-efficient green buildings may not be as well-suited to radiant-floor heating. Here’s why:

Economics

It can be reasonably argued that a green home in a moderate-to-cold climate should have very high levels of insulation (at least R-25 walls and R-40 ceiling/roof), extremely low infiltration rates, high-performance glazing (unit U-factors below 0.3), and at least some passive solar gain or sun-tempering.

We’re not talking about conventional houses, mind you, but high-performance green homes. Such a house will use very little heating energy—probably less than 2.0 Btu/ft2 · degree-day (41 kJ/m2 · °C), which would translate into very low heating costs. To achieve that level of energy performance requires a significant investment in the building envelope (for example, double 2×4 walls). In such a house, putting in an expensive heating system doesn’t make good economic sense. As Rosenbaum notes, “It just doesn’t make sense to put in a $10,000 heating system to provide $100 worth of heat per year.”

Investing so much money in the building envelope and still putting in an expensive radiant-floor heating system eliminates the potential for offsetting much of the extra cost in building envelope improvements through savings in the mechanical equipment—one of the key principles of integrated, whole-systems building design. In most highly energy-efficient houses, the same high level of comfort provided by a radiant-floor heating should be achievable simply by installing one or two small, quiet, high-efficiency through-the-wall gas heaters (such as those produced by Rinnai) or a few short sections of electric baseboard heat. At $1,000 to $2,000 apiece for Rinnai heaters (installed) or a few hundred dollars for electric baseboard vs. $10,000 for a typical radiant-floor heating system, savings of $6,000 to over $9,000 would be possible—and that savings could pay for most of the envelope improvements required to bring the heating load so far down that space heating (instead of distributed heat) becomes a viable option.

Even Larry Drake, a strong proponent of radiant-floor heating systems as executive director of the Radiant Panel Association in Loveland, Colorado, admits that radiant heat is more difficult to justify in high-performance buildings. “The tighter the envelope, the less the amount of savings of a radiant system,” he told EBN.

Heating performance with micro-loads

Along with the economic questions about the wisdom of radiant-floor heating systems for high-performance green homes, there are building science reasons why this may not be a great fit. Heat is transferred from an exposed slab to the space at a rate of about 2 Btu/ft2 · hr · °F (11 w/m2 · °C), according to Rosenbaum. In a well-insulated house, this rate of heatflow means that even when it is very cold outside, the slab can only be a few degrees warmer than the rest of the room or the room will keep heating up. For a concrete slab to feel warm, however, it needs to be about 80°F (27°C). Thus, for most of the heating season, the greatest feature of radiant-floor heat—a warm floor—won’t occur. With moderate solar gain, heat delivery from a floor slab will be even less. Because the floor is insulated underneath, it will be more comfortable to walk on than most slab floors, but the benefit will be from the insulation, not the radiant heat.

The time lag of heat movement through concrete can also be a problem. In a very well-insulated house, that lag time can result in overheating, particularly if there are other sources of heat being delivered to the space, such as passive solar. If a concrete slab is “charged” with heat during the early morning hours and the surface is warmed to the point where it cannot readily absorb solar radiation striking it, that solar heat will more directly heat the air, increasing the risk of overheating. The same thing happens to a much greater extent in high-performance passive solar homes with masonry heaters because the surface of an operating masonry heater is at a higher temperature. In such houses, occupants usually need to check weather forecasts—if they load up the masonry heater firebox in the morning and it turns out to be a bright, sunny day, the space will very likely overheat. A radiant floor maintains a much lower surface temperature than a masonry heater, so the floor will effectively “turn off” as the room warms up with solar gain. “If the floor temperature is 76°F,” says Rosenbaum, “then the radiant system can’t heat the place to hotter than that.” Therefore, this isn’t a huge problem with radiant-floor heating systems, but it may mean that homeowners will have to open windows periodically in the winter and their overall energy savings from solar energy will not be as great. Shapiro counsels against the use of radiant slabs in areas of houses with passive solar heat. “It’s a waste of energy,” he says, though just how much waste occurs is unclear.

The risk of overheating with concrete-slab radiant-floor heating systems in very energy-efficient buildings leads some designers to incorporate sophisticated control systems. Rather than a simple room thermostat, many radiant-floor designers install control systems that also adjust the circulating water temperature based on outside air temperature and the temperature of the slab. It can also be important to have different zones in a concrete-slab radiant-floor heating system—so that less heat can be delivered, for example, to portions of the slab that are warmed by solar gain. However, according to Rosenbaum, a radiant-floor slab is somewhat self-regulating when it comes to solar gain. If the floor slab begins absorbing solar heat and warms up, it will extract less heat from the circulating water; that heat will return to the boiler and can be circulated to nonsolar zones.

Heat loss into the ground

With slab-on-grade radiant-floor heating systems, there is potential for significant heat loss into the ground. According to Paul Torcellini, Ph.D., P.E., of the National Renewable Energy Laboratory, even with insulation under the slab, 20% of the heat entering the slab can be lost into the ground. This reduces the overall efficiency of the radiant-slab system, offsetting the potential savings described above. Typical manufacturer recommendations for 1” (25 mm) of XPS insulation beneath a radiant slab are clearly inadequate; even 2” (50 mm) may not be enough. Shapiro recommends up to 4” (100 mm) in cold climates. In place of ozone-depleting XPS, one can use high-density expanded polystyrene (minimum 1.5 pcf, 24 kg/m3 foam recommended).

It is ironic that most people want radiant floor heat because they don’t like a cold floor, yet there has long been resistance to insulating beneath concrete floor slabs—which would dramatically reduce the cold-floor problem. They solve the problem with an expensive radiant-floor heating system (including rigid insulation under the slab) when the rigid insulation alone would solve most of the problem. (To be fair to radiant-floor heating proponents, the only way to make a slab floor actually warm to the touch is to provide radiant-floor heating—because the high conductivity of concrete makes a slab feel cool even when it is at or slightly above room temperature.)

Challenges with cooling

Most radiant-floor heating systems cannot provide cooling, and most homes and small commercial buildings are being built today to provide cooling—even in relatively cool climates. This is why forced-air systems are far more popular than hydronic heating systems nationwide—the ducts used for forced-air heating can also be used to deliver chilled air (see further discussion under “Radiant-Floor Heating vs. Forced-Air Heating” below). One of the problems in turning a floor into a heat sink is the risk of condensation on the cool surface. (Condensation occurs when a surface temperature drops below the dew point—which can be quite high in more humid parts of the country.)

Radiant cooling (generally with ceiling panels) is used quite commonly in Europe, where humidity levels are generally not as high as in eastern North America and where the comfort envelope of building occupants (the temperature range at which they are comfortable) is wider than here. That said, there is some interesting research underway in the U.S. on radiant cooling. This concept is being tried out, for example, at an architecture school studio at Penn State University. Chilled water is circulated through ceiling panels to provide radiant cooling, with 100% fresh air used for ventilation. The key is that the ventilation air is dehumidified before delivery to the conditioned space, thus eliminating the potential for condensation on the radiant ceiling panels. This system is saving energy in two ways: because pumping water requires less energy than moving air, and because the chilled water has to remove only the sensible heat loads—not the latent loads. With the 100% outside-air supply, the total amount of circulated air is reduced by about 80%, compared with conventional recirculating systems.

Predicted vs. actual savings

The final concern with radiant-floor heating systems is that much of the assumed energy savings may not be occurring. There is very little hard data to back up the common claim that radiant-floor heating systems save a lot of energy because people with this form of heat are comfortable at lower temperatures and thus keep their thermostats lower. In fact, the only study we could find shows this not to be the case.

Last winter, the Canada Mortgage and Housing Corporation (CMHC) carried out a study of 75 houses in Nova Scotia: 50 with radiant-floor heating and 25 with other heat distribution systems—research that was first reported in the December 2001 issue of the Journal of Light Construction. These houses were visited during daylight hours on weekends, and thermostat settings were recorded. Thermostat settings in the houses with radiant-floor heating averaged 68.7°F (20.4°C), while settings in the control houses averaged only 67.6°F (19.8°C). Although the sample size was small, this study shows no evidence that homeowners with radiant-floor heating keep their thermostat settings lower; in fact, it shows the opposite. Don Fugler of CMHC, who managed the research project, told EBN that they launched the study after a radiant-floor heating product manufacturer contacted CMHC asking for more detail on standard information the agency had been giving out about the energy savings from radiant-floor heat. He cautions that this was a very superficial study, but that it points out the need for additional research into the common claim about energy savings.

Larry Drake of the Radiant Panel Association says that the CMHC study was very interesting and the conclusions being drawn from it are misleading. “To assume that people don’t feel comfortable at lower temperature is conjecture,” he said. He argues that the relationship between comfort and mean radiant temperature has been well established by ASHRAE for decades. He speculates that if homeowners with radiant heat have opted to keep their thermostats about where they keep them without radiant heat, they have opted to increase their level of comfort rather than going for the energy savings. He also suggests that homeowners may tend to set their thermostats numerically, irrespective of comfort—so that if they used to keep their thermostats at 70°F and then put in radiant-floor heating, they may well still keep their thermostats at 70° (and end up being more comfortable).
Andy Shapiro prefers not to make claims about energy savings with radiant-floor heat. “Radiant heat can be a wonderful amenity in a house,” he says, “but to sell it as an energy saver stretches the point.”

Radiant-Floor Heating vs. Forced-Air Heating

Many people who opt for radiant-floor heating do so because they don’t like forced-air heat. There is a common perception that forced-air heating systems dry out air and generate dust. “Nothing could be farther from the truth with a properly installed forced-air system,” says Betsy Pettit, AIA, of Building Science Corporation in Westford, Massachusetts. Forced-air systems, she argues, offer the benefit of being “all things to all systems.” A forced-air system can provide heat, air conditioning, ventilation, and filtration—all through a single system of ducts and with shared fans. A radiant-floor heating system, on the other hand, only does one thing, according to Pettit, and it does it at a cost that is typically higher than that of a forced-air system serving those multiple functions. “For me it’s just a hard sell,” she told EBN. “If you insulate the slab and if you build your building envelope correctly—that is to say, leak-free—you can be more comfortable for less money with a ducted distribution system,” she says.

Pettit could think of no tract-home builders in the U.S. who install radiant-floor heating, though there are many custom and spec builders who are very happy with radiant-floor heat. Max Strickland confirms that cost is indeed higher for radiant-floor heat—typically 50% higher than for forced-air—but he notes that if you provide the same level of zoning with forced-air, the costs would be much closer. He deals with air conditioning in houses that have radiant-floor heat by putting in ductless mini-split air conditioners made by Fujitsu, Sanyo or Mitsubishi, which he says are very efficient.  Drake was unaware of any large tract-home builders who have adopted radiant-floor heating over forced-air systems.

When and Where Radiant-Floor Heating Makes Sense

It has been pointed out that radiant-floor heating systems may not be the best choice for extremely well-insulated, passive solar homes. So when do they make sense?

  • In houses and small commercial buildings with conventional levels of insulation and standard insulated-glass windows—especially those in climates with minimal cooling loads—where the extra comfort of radiant heat is desired and the budget allows.
  • In buildings with large open spaces and tall ceilings.
  • In buildings where air-flushing is common, such as garages, fire stations, airplane hangars, and industrial spaces (because the large-area radiant floor allows quick recovery).
  • When cost is not an issue and satisfying most or all of the heating load with solar energy is a high priority.
  • When building occupants have acute chemical sensitivity or allergies—in which case there may be concern that dust could be distributed through a forced-air system or that high surface temperatures from a gas burner or electric heating element will burn dust particles and cause health problems.

Final Thoughts

It’s hard to express doubts about something that’s really popular. Like ground-source heat pumps, radiant-floor heating has a loyal and zealous following of builders, designers, and homeowners who consider it to be the best heating option around—and appropriate in almost any situation.

One of the reasons radiant-floor heating is so popular is that it is so much more comfortable than what most of us have experience with: older, drafty houses where there is significant floor-to-ceiling temperature stratification. If more people realized that the same—or at least a similar—level of comfort could be achieved simply by creating a really well-insulated, tight building envelope, we could be keeping a lot of people extremely comfortable while also saving a huge amount of energy, without needing radiant-floor heat. “A house with a good enough envelope to be called green—well-insulated and tight—will have a very high level of comfort no matter what type of heating system is used,” says Shapiro, “as long as that heating system is well designed.”

In homes with conventional levels of insulation and typical glazings, radiant-floor heating is an extremely comfortable heat-distribution option. It does not contribute to IAQ problems, and it might well even save a little energy if homeowners can be convinced to turn down their thermostats to a level that will provide the same level of comfort as a house without radiant heat. But in an extremely well-insulated, green home, radiant-floor heating usually is not the best option. If you’ve gone to all the effort and spent all the money to achieve a truly stand-out energy-conserving envelope with passive solar gain, why not offset that cost by dramatically reducing the cost of the heating system?

– Alex Wilson

For more information:
Radiant Panel Association
P.O. Box 717
Loveland, CO 80539
800/660-7187, 970/613-0100
970/613-0098 (fax)
www.radiantpanelassociation.org
For subscription information contact: Environmental Building News,
122 Birge St., Suite 30, Brattleboro, VT 05301 (USA). E-mail: ebn@
BuildingGreen.com. Web site:www. BuildingGreen.com

Posted by Wes Diskin

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Asthma Triggers and Information

May 22nd, 2013

Asthma is a serious lung disease.

* During an asthma attack, the airways get narrow, making it difficult to breathe.
* Symptoms of asthma include wheezing, shortness of breath, and coughing.
* Asthma can even cause death.


If you have asthma or a child with asthma, you are not alone.

* About 17 million Americans have asthma.
* Asthma is the leading cause of long-term illness in children.

The air that children breathe can make a difference.
* Asthma may be triggered by allergens and irritants that are common in homes.
* Help your child breathe easier: consult a doctor and reduce asthma triggers in your home.

Clear Your Home Of Asthma Trigger

Below are five common asthma triggers found in homes and what you can do to reduce you and your child’s exposure to them.

  • Not all of the asthma triggers listed here affect every person with asthma.
  • Not all asthma triggers are listed here.
  • See your doctor or health care provider for more information.

Secondhand Smoke

Asthma can be triggered by the smoke from the burning end of a cigarette, pipe, or cigar and the smoke breathed out by a smoker.

  • Choose not to smoke in your home or car and do not allow others to do so either.

Dust Mites

Dust mites are too small to be seen but are found in every home.

Dust mites live in mattresses, pillows, carpets, fabric-covered furniture, bedcovers, clothes, and stuffed toys.

  • Wash sheets and blankets once a week in hot water.
  • Choose washable stuffed toys, wash them often in hot water, and dry thoroughly. Keep stuffed toys off beds.
  • Cover mattresses and pillows in dust-proof (allergen-impermeable) zippered covers.

Pets

Your pet’s skin flakes, urine, and saliva can be asthma triggers.

  • Consider keeping pets outdoors or even finding a new home for your pets, if necessary.
  • Keep pets out of the bedroom and other sleeping areas at all times, and keep the door closed.
  • Keep pets away from fabric-covered furniture, carpets, and stuffed toys.

Molds

Molds grow on damp materials. The key to mold control is moisture control.

If mold is a problem in your home, clean up the mold and get rid of excess water or moisture.

Lowering the moisture also helps reduce other triggers, such as dust mites and cockroaches.

  • Wash mold off hard surfaces and dry completely. Absorbent materials, such as ceiling tiles and carpet, with mold may need to be replaced.
  • Fix leaky plumbing or other sources of water.
  • Keep drip pans in your air conditioner, refrigerator, and dehumidifier clean and dry.
  • Use exhaust fans or open windows in kitchens and bathrooms when showering, cooking, or using the dishwasher.
  • Vent clothes dryers to the outside.
  • Maintain low indoor humidity, ideally between 30-50% relative humidity. Humidity levels can be measured by hygrometers which are available at local hardware stores.

Pests

Droppings or body parts of pests such as cockroaches or rodents can be asthma triggers.

  • Do not leave food or garbage out.
  • Store food in airtight containers.
  • Clean all food crumbs or spilled liquids right away.

Try using poison baits, boric acid (for cockroaches), or traps first before using pesticidal sprays.
 If sprays are used:

  • Limit the spray to infested area.
  • Carefully follow instructions on the label.
  • Make sure there is plenty of fresh air when you spray, and keep the person with asthma out of the room.

Also… House dust may contain asthma triggers. Remove dust often with a damp cloth, and vacuum carpet and fabric-covered furniture to reduce dust build-up. Allergic people should leave the area being vacuumed. Using vacuums with high efficiency filters or central vacuums may be helpful.

When your local weather forecast announces an ozone action day, stay indoors as much as possible.

Posted by Wes Diskin

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All About Ductless – An Overview

May 3rd, 2013

Save Energy & Money

A Ductless Heat Pump is a highly efficient heating and cooling system that is easily installed as a new primary heat source for electrically heated homes. Ductless systems heat and cool homes at a fraction of the cost of baseboards and wall heaters.

More Comfortable.

Ductless systems do a better job of distributing warm or cool air around a home, thus making your living areas more comfortable. They are especially well suited to homes with open floor plans, as one indoor unit can heat/cool a large living space quite well.

Easy to Install.

The ductless system design allows you to retain the original aesthetics of a room. They do not require expensive and invasive ductwork; they require only a three-inch opening in the wall or ceiling. Installation is as simple as mounting the indoor and outdoor units, connecting the refrigerant lines, and making a few electrical connections. Most installations can be done in a day or two.

APPLICATIONS

Ductless Heating and Cooling systems can be used to heat and cool a wide variety of spaces. Here are a few popular residential applications:

  • Homes with Electric Heat – Ductless systems can replace or supplement inefficient existing electric baseboard/wall/ceiling units, woodstoves and other space heaters (propane, kerosene). A cost effective electric heat conversion in a small house might consist of a Ductless system serving the main area of the house, while leaving existing electric baseboards in bedrooms and bathrooms for supplementary heat when needed.
  • Remodels and Room Additions – A Ductless system can be used when a room is added to a house or an attic is converted to living space. Rather than extending the home’s existing ductwork or pipes or adding electric resistance heaters, the ductless heat pump can provide efficient heating and cooling.
  • New Construction – New homes can be designed or adapted to take advantage of the characteristics of ductless heat pumps. One or more systems might be installed in various “zones” of the house to simplify installation and minimize refrigerant line length.

PROVEN TECHNOLOGY

Ductless systems have been around for several decades and are manufactured by many of the companies you’re used to buying products from. You can rest assured that your investment is in a proven technology that you will be happy with for many years to come.

Posted by Wes Diskin

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Ductless Heat Pumps – Questions…Answered.

April 2nd, 2013

Q: What is a ductless heating and cooling system?

A ductless heating and cooling system is a highly efficient zonal heating and cooling system that does not require the use of air ducts. Ductless systems consist of an outdoor compressor unit and one or more indoor air-handling units, called “heads”, linked by a dedicated refrigerant line. Indoor heads are typically mounted high on a wall or ceiling covering a 3” hole where the refrigerant line passes through from the outside unit, which is mounted at the base of the house. Each indoor head corresponds with a heating and cooling zone that can be controlled independently.

Q: Do I still need my old heaters?

While a ductless system can be used as a primary heat source, homeowners are encouraged to keep their existing electric heating units as a supplement the Ductless system in case of extreme weather conditions or in hard to reach extremities of the home.

Q: How does a ductless system work?

Ductless systems are reversible, 2-way heat pumps that use electricity to transfer heat between outdoor and indoor air by compressing and expanding refrigerant. Using a refrigerant vapor compression cycle, like a common household refrigerator, ductless systems collect heat from outside the house and deliver it inside on the heating cycle, and vice versa on the cooling cycle. Ductless systems use variable speed compressors with “inverter technology” (AC to DC) in order to continuously match the heating/cooling load, avoiding the on/off cycling of conventional electric resistance and central heating systems that is commonly associated with uncomfortable temperature variations and high energy consumption.

Ductless Systems consist of several parts:

  • An outdoor unit that contains a condensing coil, an inverter-driven variable speed compressor, an expansion valve and a fan to cool the condenser coil.
  • An indoor unit that contains an evaporator and a quiet oscillating fan to distribute air into throughout the heating zone.
  • A refrigerant line-set that is made of insulated copper tubing and is housed in a conduit alongside a power cable, and a condensation drain.
  • A remote control that can be used to set the desired temperature and program in night-time settings.

Q: How is the system controlled?

The system is controlled via remote control that changes temperature as well as mode of operation. Wall mounted controls are also available.

Q: What are appropriate applications for a ductless system?

  • Replacing an existing zonal heating system – Ductless systems are ideal for replacing or supplementing inefficient electric baseboard, wall or ceiling units, woodstoves and other space heaters such as propane or kerosene. A cost effective electric heat conversion in a small house might consist of single system serving the main area of the house, while leaving existing electric baseboards in bedrooms and bathrooms.
  • Room additions – A ductless system can also be implemented when a room is added onto a house or an attic is converted to living space. Rather than extending the home’s existing ductwork or pipes, or adding electric resistance heaters, the ductless sytem can provide efficient heating and cooling.
  • New construction – New home designs can be adapted to take advantage of a ductless system’s many benefits. One or more systems might be installed in various “zones” of the house to simplify installation and minimize refrigerant line length.

Q: Are ductless systems efficient?

Yes! Ductless systems operate using 50% to 75% less energy than electric resistance and forced air systems. Three key factors account for the high efficiency of a ductless system:

  1. Ductless systems allow the user to control each heating/cooling zone independently, eliminating the costly over-heating and cooling common to central air systems. Why pay to heat or cool rooms that are not currently occupied?
  2. While central air systems lose as much as 30% efficiency through air leaks and conduction in the ductwork, ductless systems distribute air directly to each zone, resulting in 25% greater efficiency. Ductless systems use inverter-driven, variable speed compressors that allow the system to maintain constant indoor temperatures by running continuously at higher or lower speeds. Thus, the system can ramp-up or down without great losses in operating efficiency, avoiding the energy intensive on/off cycling common in electric resistance and forced air systems.
  3. Modern ductless systems have ultra-high Seasonal Energy Efficiency Ratios (SEER) between 16 and 22, and Heating Seasonal Performance Factors (HSPF) between 8.5 and 12.

Q: How long have ductless systems been around?

Ductless heating and cooling systems were developed in Japan in the 1970’s and have since become a preferred heating and cooling system throughout Asia and much of Europe. In the United States ductless systems have been used in commercial applications for over 20 years.

Q: How much does a ductless system cost?

The average cost of an installed ductless systems with a single indoor heating/cooling zone is between $3,000 and $5,000. Additional heating zones and greater heating capacities will increase the cost of the system. Other factors that will affect the cost of an installed system include manufacturer and model, refrigerant line-set length, difficulty of installation, and contractor rates.

Q: What incentives are available for ductless systems?

  • Utility Rebates: most utilities in the Northwest are offering their customers cash rebates as high as $1,500 when they upgrade their existing electric resistance heating system to a ductless system. Interest-free financing may also be available. Check with your local utility for details.
  • Federal Tax Credits – Additional Incentives: Federal Tax Credits: tax credits for Consumer Energy Efficiency may be available to taxpayers who purchase a qualified energy-efficient residential ductless systems.

Q: How long will a ductless system last?

With proper maintenance and care a ductless systems should perform for over 20 years. Many of the systems installed during the 1980’s are still functioning well today.

Q: What kind of maintenance does a ductless system require?

Ductless systems require basic maintenance to ensure optimum performance. In most cases maintenance is limited to keeping filters and coils clean. These tasks can easily be performed by the home owner.

Q: How do I know what sized system my house needs?

Ductless systems are sized to meet the heating and cooling needs of a home’s individual zones. There is a great deal of flexibility when it comes to system sizing as one indoor unit can provide between ¾ and 2 ½ tons of heating/cooling depending on its BTU capacity rating. Some common capacities for indoor units are 9k, 12k, 18k, 24k, and 30k BTU. Outdoor units are sized to meet the combined load of all heating/cooling zones. More than one outdoor unit may be necessary for multi-zone systems.

Posted by Wes Diskin

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Equipment You Shouldn’t Keep – Knowing When to Cash In

March 29th, 2013

When you move into an existing home, there are many pieces of equipment that you may not want to keep. Some of them are just old and poor quality, while others cost you a lot of money and others still may be dangerous to you or your children. Before you settle into your space, make sure you have every one of your systems checked thoroughly for potential problems including inefficient heating, dangerous parts or environmentally unfriendly components.

Energy Cost

Number one on your list should be the cost of the energy needed to run your HVAC equipment. Furnaces and air conditioners in particular have become much more energy efficient in the last 10 years so older systems routinely cost much more money to operate than new ones. That doesn’t mean you should immediately rush out to replace your old furnace, but if it isn’t working properly or it’s costing you more money than you’d like, the cost benefit of a new system is often worth checking into.

Other things to check include your insulation, your air quality system, your ventilation system and anything used to heat or cool food in the kitchen – all of which may be less efficient than you might like.

Ozone Depleting Refrigerants

Older appliances like air conditioners may still use ozone depleting refrigerants that are no longer considered safe (or in some cases legal) for home use. If this is the case, not only does your system probably have a very low SEER/HSPF rating, it likely isn’t good for the environment or your own health. So, have your system replaced as soon as possible to avoid potentially negative side effects.

Dangerous Equipment

Finally, there are those pieces of equipment that are dangerous. If you find that your furnace has rust around the edges, your gas lines are kinked, or you have a dangerously out of date heat pump in your backyard, it may be time for some replacements. In general, these systems will last for years longer than they are considered safe and while you probably cannot buy a house without a working and safe furnace and air conditioner, you should still have them inspected carefully and replaced as soon as possible if you suspect problems.

Good HVAC equipment is hard to come by – if your home has it already, you’re in luck, but if you happen to move into a place with poor quality materials and equipment, have it replaced as soon as possible. Your health and wallet will both benefit greatly.

Posted by Wes Diskin

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Understanding Efficiency Ratings of Furnaces

March 21st, 2013

A central furnace or boiler’s efficiency is measured by annual fuel utilization efficiency (AFUE). The Federal Trade Commission requires new furnaces or boilers to display their AFUE so consumers can compare heating efficiencies of various models. AFUE is a measure of how efficient the appliance is in the energy in its fuel over the course of a typical year.

Specifically, AFUE is the ratio of heat output of the furnace or boiler compared to the total energy consumed by a furnace or boiler. An AFUE of 90% means that 90% of the energy in the fuel becomes heat for the home and the other 10% escapes up the chimney and elsewhere. AFUE doesn’t include the heat losses of the duct system or piping, which can be as much as 35% of the energy for output of the furnace when ducts are located in the attic.

An all-electric furnace or boiler has no flue loss through a chimney. The AFUE rating for an all-electric furnace or boiler is between 95% and 100%. The lower values are for units installed outdoors because they have greater jacket heat loss. However, despite their high efficiency, the higher cost of electricity in most parts of the country makes all-electric furnaces or boilers an uneconomic choice. If you are interested in electric heating, consider installing a heat pump system.

The minimum allowed AFUE rating for a non-condensing fossil-fueled, warm-air furnace is 78%; the minimum rating for a fossil-fueled boiler is 80%; and the minimum rating for a gas-fueled steam boiler is 75%. A condensing furnace or boiler condenses the water vapor produced in the combustion process and uses the heat from this condensation. The AFUE rating for a condensing unit can be much higher (by more than 10 percentage points) than a non-condensing furnace. Although condensing units cost more than non-condensing units, the condensing unit can save you money in fuel costs over the 15- to 20-year life of the unit, and is a particularly wise investment in cold climates.

You can identify and compare a system’s efficiency by not only its AFUE but also by its equipment features, listed below.

Old, low-efficiency heating systems:

  • Natural draft that creates a flow of combustion gases
  • Continuous pilot light
  • Heavy heat exchanger
  • 68%–72% AFUE

Mid-efficiency heating systems:

  • Exhaust fan controls the flow of combustion air and combustion gases more precisely
  • Electronic ignition (no pilot light)
  • Compact size and lighter weight to reduce cycling losses
  • Small-diameter flue pipe
  • 80%–83% AFUE

High-efficiency heating systems:

  • Condensing flue gases in a second heat exchanger for extra efficiency
  • Sealed combustion
  • 90%–97% AFUE

Posted by Wes Diskin

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Home Ventilation Options – Make it Tight, Ventilate Right

March 9th, 2013

All the fancy air quality control tools in the world are useless if you don’t have a good ventilation system to circulate air through your home each day. An air filter removes larger particles like dust, dander and pollen, and an electronic air filter removes smaller particles like bacteria, mold, and gases. However, your indoor air will still be poor without a fresh supply of air constantly circulating in from outdoors.

Types of Ventilators

There are a few options here, depending both on the number of contaminants your home has and the amount of heated or cooled air you are willing to lose each day through vents.

The simplest method is an exhaust fan. Fans blow air from your home, creating a negative pressure zone inside. Air inlets then allow new air to enter your home and equalize that pressure. There are also balanced exhaust fans – one fan blowing indoor air out and another fan pulling fresh air in. If you have open flames or gas burning appliances, a balanced exhaust fan is necessary to keep the flames from going out due to the negative pressure caused by a single outlet exhaust fan.

Traditional ventilation, while simple, is also inefficient. In the middle of winter it blows all of your heated air outside and in the summer, it does the same to your cooled air. Your home comfort system likely can keep up with the loss of heat or cooling, so you won’t be less comfortable, but you will certainly pay more on your energy bill.

That’s why heat and energy recovery ventilators are popular in many homes. Especially if you went to the trouble of having your home sealed up tightly to minimize energy loss, these ventilators will save you money.

When air is ventilated through a recovery unit, the energy and heat is transferred between indoor and outdoor air as it passes. In the winter, this means the energy in your indoor air is retained and during the summer, the energy in outdoor air is removed before it enters your home.

Which Method is Best?

The method you choose will depend largely on your current cost of heating and cooling and what types of contaminants you face. Energy recovery ventilators have the added benefit of patching directly into your indoor air quality units, so you won’t need to worry about new contaminants coming in either.

Posted by Wes Diskin

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10 Buying Mistakes to Stay Away From – Helpful Hints for New Equipment

February 28th, 2013

Every year millions of homeowners buy a new HVAC system for their home. Whether for heating, cooling or air quality, they make a huge investment in a new system that will be with them for years to come. Unfortunately, many of those people make big mistakes when buying their next system, so to help you avoid doing so, here are some simple things you should not do.

Ignoring Air Quality – Air quality is about more than comfort. It affects the health of everyone in your home equally. Consider it carefully when installing a new system.

Avoiding Even Heating and Cooling – One room being cooler or warmer than another is not okay. It’s bad for your system and bad for your home’s comfort level. Have insulation and ductwork checked before installation of a new HVAC system.

Not Upgrading Your AFUE or SEER – New systems are highly efficient. Take advantage of that by buying one with a higher AFUE or SEER rating.

Not Vetting Your Contractor – Always spend time checking up on your contractor, reading reviews and asking other customers how their experience was.

Skipping the Service Agreement – Service agreements save money and help your system last longer. Don’t skip them.

Buying the Cheapest Option Available – It may be tempting, but a cheap HVAC system is a bad idea if you want it to last and save you money in heating and cooling. Even a midrange system will save you money in only a few years with higher efficiency ratings.

Picking the Same Model You Already Had – New models are stronger and more efficient. When possible, get an upgrade and your bills will reflect the difference.

Waiting too Long to Buy – The longer you wait, the more you pay in heating and cooling bills for an old, worn down system. If you know you’re going to buy a new system, act fast to save the most possible money.

Not Asking Questions – If you have a question, ask it. There is no such thing as a stupid question when looking for a new HVAC system.

Ignoring Maintenance Recommendations – Maintenance recommendations are optional but almost always to your benefit. Research on your own before committing to anything, but don’t ignore the necessity either.

If you do things just right, your new HVAC system will last for years to come and provide steady, comfortable heating or cooling throughout that time. But, if you rush through things, make a hasty decision and neglect to do any research, you may have issues with your system in far less time than you’d like. Be smart and you’ll be rewarded.

Posted by Wes Diskin

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The 3 Fan Motor Types – ECM Unmasked

February 1st, 2013

It is not commonly known that there are 3 Fan Motor Types, nor is it commonly known to the consumer what the differences are. Below is a brief description of how the three differ and an extended article on the many benefits of the Variable Speed Fan Motor that was written by me previously. As always, thank you for reading.

The PSC Fan Motor. This is also known as the Standard Blower. It usually has around 4 speeds of which one will be selected for when the heat comes on based on the Delta T. The cost to operate this blower 24/7 is approximately $353 per year (based on 3 ton). It is often found in the Single and 2 Stage Furnace.

The X-13 Constant Torque Fan Motor. Also known as just the X-13 ECM or X-13 BOOST because it tends to increase the efficiency ratings of Heat Pumps in order to qualify for rebates. This too has around 4 speeds that will be tapped based on the Delta T, however, this motor will allow the installer to set up a CONSTANT FAN tap to ramp the blower down to 60% of its heating speed to give constant circulation at lower velocities. The cost to operate this blower 27/7 is approximately $120 per year (based on 3 ton). That is having your fan on 24/7, however, at during heating cycles this blower matches the efficiency of the Variable Speed ECM detailed below. This blower is also FAR more forgiving than the Variable when it comes to the existing duct design of different homes.

The Variable Speed ECM Fan Motor

One of the best descriptions is by Danny Heinman

“For any furnace, providing maximum comfort means achieving the proper amount of airflow. This is true for both heating and cooling operations. Unlike conventional single speed motors, a variable speed motor runs at a wide range of speeds. Using intelligent technology, it continually monitors incoming data from your heating and cooling system, and it automatically makes the adjustments necessary to meet your comfort needs. The motor varies the amount of air circulated, compensating for factors like dirty filters by increasing speed. Put simply, it delivers just the right amount of air necessary to provide the desired level of heating and cooling comfort.”

The variable speed motor is very diverse, but it has one flaw. NO speed taps. So if I put this blower into ducting that is designed poorly or has too much restriction, it will ramp up and up and up and up and then finally make you hate me! So, we are very picky about who gets these blowers, however, some duct issues are also easy to solve. That being said, because there are no taps, this motor ramps down to about 30% of its capacity to give you wonderful constant fan operation (see article below). The cost to operate this blower 27/7 is approximately $40 per year (based on 3 ton).

Below is part of an article I wrote about 3 years ago that still rings true.

DISCLAIMER – before running any fan 24/7 your ducts should be sealed. Read more about AeroSeal duct sealing. http://healthefficiencycomfort.blogspot.com/search/label/Duct%20Sealing

…We will start with the most important of the three, which may not be the one you would expect. It is your Health. There is an insane amount of data that will back up my claim, but all you need to know is that while you can see “dust” in the air and settled on surfaces, about 99% of the particles in the air are smaller than 1 micron (1 millionth of a meter). The human eye can only see particles bigger than 10 microns in size. So next time you are looking at all the dust in your air when the sun is shining in your window, think, “Wow, that is only 1%?!” and then call me.

How variable speed effects your health is really very simple. Tell me, what is your furnace doing when it is 68 degrees out side? That’s right, nothing. What is your filter doing while your furnace is doing nothing? More nothing. That is where variable speed comes in; when the furnace is not heating or cooling and the fan in is constant operation,variable speed furnace will continue to slowly and inexpensively circulate air throughout your home. This allows your filters to capture more contaminants (because air is constantly passing through them), so you can breathe easier.

From a Comfort stand point, variable is a god send. Literally, a gift to man sent from heaven. The hilarious thing is that it is just so simple. The element that it all boils down to is constant air flow, period. That is it. Most people do not turn on their fan 24/7 because they believe it will cost them a lot of money (on a standard blower they are correct) and more often than not, it is just too loud. What variable blowers do is ramp the blower down so you do not notice it running, nor does it cost you any more money than standard furnace operation.

Sorry, back to Comfort. Here is what variable speed will do by providing constant air flow. The greatest thing is the even heating and cooling you get. Instead of having the upstairs hot and downstairs cold, variable combines those two environments to create an equal and balanced air temperature. When I turn off my fan in my home the upstairs will generally be about 7-8 degrees warmer than my downstairs; once I turn it back on, the spread becomes 1 degree if not the same! It also solves the age old issue of Cold Blow. This is the burst of cold air that comes from the ducts before the hot air gets to you, just like the cold water at your faucet. Well, just like plumbers have circulation pumps that keep hot water in the pipes at all times so when you turn on the faucet you just get hot water, we do the same thing with variable speed. When the furnace turns on, the ducts are already tempered with warm air flowing through them constantly, so you do not feel that blast of cold air in between heating cycles!

Next is Savings. Not only is the blower itself more efficient at about 8-10x that of a standard blower, but it makes everything it is attached to more efficient as well. You will consistently get better efficiency ratings on heat pumps and air conditioners that are attached to a variable speed system. Not only that, your furnace will operate better and your filters work harder for you.

Perhaps the most abstract, but exciting, feature that variable speed offers is the use of latent BTUs to evenly heat your home. When you touch a light bulb it is hot, your audio/video system is hot, your refrigerator pumps out heat like crazy, and you emit 400 BTUs per hour yourself, not to mention Solar heat gain! Just think if there was a way to take all that heat being generated and distribute it all throughout the house, creating less need for your heating system to turn on! Of course, you know the answer.

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Biological Pollutants In Your Home – Clearing the Air

January 24th, 2013

This page will help you understand:

  1. what indoor biological pollution is
  2. whether your home or lifestyle promotes its development
  3. how to control its growth and buildup

Outdoor air pollution in cities is a major health problem. Much effort and money continues to be spent cleaning up pollution in the outdoor air. But air pollution can be a problem where you least expect it, in the place you may have thought was safest–your home. Many ordinary activities such as cooking, heating, cooling, cleaning, and redecorating can cause the release and spread of indoor pollutants at home. Studies have shown that the air in our homes can be even more polluted than outdoor air.
Many Americans spend up to 90 percent of their time indoors, often at home. Therefore, breathing clean indoor air can have an important impact on health. People who are inside a great deal may be at greater risk of developing health problems, or having problems made worse by indoor air pollutants. These people include infants, young children, the elderly, and those with chronic illnesses.

What Are Biological Pollutants?

Biological pollutants are or were living organisms. They promote poor indoor air quality and may be a major cause of days lost from work or school, and of doctor and hospital visits. Some can even damage surfaces inside and outside your house. Biological pollutants can travel through the air and are often invisible.

Some common indoor biological pollutants are:

  • Animal Dander (minute scales from hair, feathers, or skin)
  • Dust Mite and Cockroach parts
  • Fungi (Molds)
  • Infectious agents (bacteria or viruses)
  • Pollen

Some of these substances are in every home. It is impossible to get rid of them all. Even a spotless home may permit the growth of biological pollutants. Two conditions are essential to support biological growth: nutrients and moisture. These conditions can be found in many locations, such as bathrooms, damp or flooded basements, wet appliances (such as humidifiers or air conditioners), and even some carpets and furniture.
Modern materials and construction techniques may reduce the amount of outside air brought into buildings which may result in high moisture levels inside. Using humidifiers, unvented heaters, and air conditioners in our homes has increased the chances of moisture forming on interior surfaces. This encourages the growth of certain biological pollutants.

The Scope of the Problem

Most information about sources and health effects of biological pollutants is based on studies of large office buildings and two surveys of homes in northern U.S. and Canada. These surveys show that 30% to 50% of all structures have damp conditions which may encourage the growth and buildup of biological pollutants. This percentage is likely to be higher in warm, moist climates.
Some diseases or illnesses have been linked with biological pollutants in the indoor environment. However, many of them also have causes unrelated to the indoor environment. Therefore, we do not know how many health problems relate only to poor indoor air.
All of us are exposed to biological pollutants. However, the effects on our health depend upon the type and amount of biological pollution and the individual person. Some people do not experience health reactions from certain biological pollutants, while others may experience one or more of the following reactions:

  • Allergic
  • Infectious
  • Toxic

Except for the spread of infections indoors, ALLERGIC REACTIONS may be the most common health problem with indoor air quality in homes. They are often connected with animal dander (mostly from cats and dogs), with house dust mites (microscopic animals living in household dust), and with pollen. Allergic reactions can range from mildly uncomfortable to life-threatening, as in a severe asthma attack. Some common signs and symptoms are:

  • Watery eyes
  • Runny nose and sneezing
  • Nasal congestion
  • Itching
  • Coughing
  • Wheezing and difficulty breathing
  • Headache
  • Fatigue

Health experts are especially concerned about people with asthma. These people have very sensitive airways that can react to various irritants, making breathing difficult. The number of people who have asthma has greatly increased in recent years. The number of people with asthma has gone up by 59 percent since 1970, to a total of 9.6 million people. Asthma in children under 15 years of age has increased 41 percent in the same period, to a total of 2.6 million children. The number of deaths from asthma is up by 68 percent since 1979, to a total of almost 4,400 deaths per year.

INFECTIOUS DISEASES caused by bacteria and viruses, such as flu, measles, chicken pox, and tuberculosis, may be spread indoors. Most infectious diseases pass from person to person through physical contact. Crowded conditions with poor air circulation can promote this spread. Some bacteria and viruses thrive in buildings and circulate through indoor ventilation systems. For example, the bacterium causing Legionnaire’s disease, a serious and sometimes lethal infection, and Pontiac Fever, a flu-like illness, have circulated in some large buildings.

Talking to Your Doctor

Are you concerned about the effects on your health that may be related to biological pollutants in your home? Before you discuss your concerns with your doctor, you should know the answers to the following questions. This information can help the doctor determine whether your health problems may be related to biological pollution.

  • Does anyone in the family have frequent headaches, fevers, itchy watery eyes, a stuffy nose, dry throat, or a cough? Does anyone complain of feeling tired or dizzy all the time? Is anyone wheezing or having difficulties breathing on a regular basis?
  • Did these symptoms appear after you moved to a new or different home?
  • Do the symptoms disappear when you go to school or the office or go away on a trip, and return when you come back?
  • Have you recently remodeled your home or done any energy conservation work, such as installing insulation, storm windows, or weather stripping? Did your symptoms occur during or after these activities?
  • Does your home feel humid? Can you see moisture on the windows or on other surfaces, such as walls and ceilings?
  • What is the usual temperature in your home? Is it very hot or cold?
  • Have you recently had water damage?
  • Is your basement wet or damp?
  • Is there any obvious mold or mildew?
  • Does any part of your home have a musty or moldy odor?
  • Is the air stale?
  • Do you have pets?
  • Do your house plants show signs of mold?
  • Do you have air conditioners or humidifiers that have not been properly cleaned?
  • Does your home have cockroaches or rodents?

TOXIC REACTIONS are the least studied and understood health problem caused by some biological air pollutants in the home. Toxins can damage a variety of organs and tissues in the body, including the liver, the central nervous system, the digestive tract, and the immune system.

Coping With the Problem

Checking Your Home

There is no simple and cheap way to sample the air in your home to determine the level of all biological pollutants. Experts suggest that sampling for biological pollutants is not a useful problem-solving tool. Even if you had your home tested, it is almost impossible to know which biological pollutant(s) cause various symptoms or health problems. The amount of most biological substances required to cause disease is unknown and varies from one person to the next.

Does this make the problem sound hopeless? On the contrary, you can take several simple, practical actions to help remove sources of biological pollutants, to help get rid of pollutants, and to prevent their return.

Self-Inspection: A Walk Through Your Home

Begin by touring your household. Follow your nose, and use your eyes. Two major factors help create conditions for biological pollutants to grow: nutrients and constant moisture with poor air circulation.

  • Dust and construction materials, such as wood, wallboard, and insulation, contain nutrients that allow biological pollutants to grow. Firewood also is a source of moisture, fungi, and bugs.
  • Appliances such as humidifiers, kerosene and gas heaters, and gas stoves add moisture to the air.
  • A musty odor, moisture on hard surfaces, or even water stains, may be caused by:
- Air-conditioning units
-

Basements, attics, and crawlspaces
- Bathrooms
- Carpets
- Heating and air-conditioning ducts
- Humidifiers and dehumidifiers
- Refrigerator drip pans.

What You Can Do About Biological Pollutants

Before you give away the family pet or move, there are less drastic steps that can be taken to reduce potential problems. Properly cleaning and maintaining your home can help reduce the problem and may avoid interrupting your normal routine. People who have health problems such as asthma, or are allergic, may need to do this and more. Discuss this with your doctor.

Moisture Control

Water in your home can come from many sources. Water can enter your home by leaking or by seeping through basement floors. Showers or even cooking can add moisture to the air in your home. The amount of moisture that the air in your home can hold depends on the temperature of the air. As the temperature goes down, the air is able to hold less moisture. This is why, in cold weather, moisture condenses on cold surfaces (for example, drops of water form on the inside of a window). This moisture can encourage biological pollutants to grow.

There are many ways to control moisture in your home:

  • Fix leaks and seepage. If water is entering the house from the outside, your options range from simple landscaping to extensive excavation and waterproofing. (The ground should slope away from the house.) Water in the basement can result from the lack of gutters or a water flow toward the house. Water leaks in pipes or around tubs and sinks can provide a place for biological pollutants to grow.
  • Put a plastic cover over dirt in crawlspaces to prevent moisture from coming in from the ground. Be sure crawlspaces are well-ventilated.
  • Use exhaust fans in bathrooms and kitchens to remove moisture to the outside (not into the attic). Vent your clothes dryer to the outside.
  • Turn off certain appliances (such as humidifiers or kerosene heaters) if you notice moisture on windows and other surfaces.
  • Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don’t become sources of biological pollutants.
  • Raise the temperature of cold surfaces where moisture condenses. Use insulation or storm windows. (A storm window installed on the inside works better than one installed on the outside.) Open doors between rooms (especially doors to closets which may be colder than the rooms) to increase circulation. Circulation carries heat to the cold surfaces. Increase air circulation by using fans and by moving furniture from wall corners to promote air and heat circulation. Be sure that your house has a source of fresh air and can expel excessive moisture from the home.
  • Pay special attention to carpet on concrete floors. Carpet can absorb moisture and serve as a place for biological pollutants to grow. Use area rugs which can be taken up and washed often. In certain climates, if carpet is to be installed over a concrete floor, it may be necessary to use a vapor barrier (plastic sheeting) over the concrete and cover that with sub-flooring (insulation covered with plywood) to prevent a moisture problem.
  • Moisture problems and their solutions differ from one climate to another. The Northeast is cold and wet; the
  • Southwest is hot and dry; the South is hot and wet; and the Western Mountain states are cold and dry. All of these regions can have moisture problems. For example, evaporative coolers used in the Southwest can encourage the growth of biological pollutants. In other hot regions, the use of air conditioners which cool the air too quickly may prevent the air conditioners from running long enough to remove excess moisture from the air. The types of construction and weatherization for the different climates can lead to different problems and solutions.
  • Maintain and Clean All Appliances that Come in Contact with Water
  • Have major appliances, such as furnaces, heat pumps and central air conditioners, inspected and cleaned regularly by a professional, especially before seasonal use. Change filters on heating and cooling systems according to manufacturer’s directions. (In general, change filters monthly during use.) When first turning on the heating or air conditioning at the start of the season, consider leaving your home until it airs out.
  • Have window or wall air-conditioning units cleaned and serviced regularly by a professional, especially before the cooling season. Air conditioners can help reduce the entry of allergy-causing pollen. But they may also become a source of biological pollutants if not properly maintained. Clean the coils and incline the drain pans according to manufacturer’s instructions, so water cannot collect in pools.
  • Have furnace-attached humidifiers cleaned and serviced regularly by a professional, especially before the heating season.
  • Follow manufacturer’s instructions when using any type of humidifier. Experts differ on the benefits of using humidifiers. If you do use a portable humidifier (approximately 1 to 2 gallon tanks), be sure to empty its tank every day and refill with distilled or demineralized water, or even fresh tap water if the other types of water are unavailable. For larger portable humidifiers, change the water as recommended by the manufacturer. Unplug the appliance before cleaning. Every third day, clean all surfaces coming in contact with water with a 3% solution of hydrogen peroxide, using a brush to loosen deposits. Some manufacturers recommend using diluted household bleach for cleaning and maintenance, generally in a solution of one-half cup bleach to one gallon water. When using any household chemical, rinse well to remove all traces of chemical before refilling humidifier.
  • Empty dehumidifiers daily and clean often. If possible, have the appliance drip directly into a drain. Follow manufacturer’s instructions for cleaning and maintenance. Always disconnect the appliance before cleaning.
  • Clean refrigerator drip pans regularly according to manufacturer’s instructions. If refrigerator and freezer doors don’t seal properly, moisture may build up and mold can grow. Remove any mold on door gaskets and replace faulty gaskets.
  • Clean
  • Clean mold surfaces, such as showers and kitchen counters.
    Remove meld from walls, ceilings, floors, and panelling. Do not simply cover mold with paint, stain, varnish, or a moisture-proof sealer, as it may resurface.
  • Replace moldy shower curtains, or remove them and scrub well with a household cleaner and rinse before rehanging them.
  • Dust Control
  • Controlling dust is very important for people who are allergic to animal dander and mites. You cannot see mites, but you can either remove their favorite breeding grounds or keep these areas dry and clean. Dust mites can thrive in sofas, stuffed chairs, carpets, and bedding. Open shelves, fabric wallpaper, knickknacks, and venetian blinds are also sources of dust mites. Dust mites live deep in the carpet and are not removed by vacuuming. Many doctors suggest that their mite-allergic patients use washable area rugs rather than wall-to-wall carpet.
  • Always wash bedding in hot water (at least 1300 F) to kill dust mites. Cold water won’t do the job. Launder bedding at least every 7 to 10 days.
  • Use synthetic or foam rubber mattress pads and pillows, and plastic mattress covers if you are allergic. Do not use fuzzy wool blankets, feather or wool-stuffed comforters, and feather pillows.
  • Clean rooms and closets well; dust and vacuum often to remove surface dust. Vacuuming and other cleaning may not remove all animal dander, dust mite material, and other biological pollutants. Some particles are so small they can pass through vacuum bags and remain in the air. If you are allergic to dust, wear a mask when vacuuming or dusting. People who are highly allergy-prone should not perform these tasks. They may even need to leave the house when someone else is cleaning.
  • Before You Move
  • Protect yourself by inspecting your potential new home. If you identify problems, have the landlord or seller correct them before you move in, or even consider moving elsewhere.
  • Have professionals check the heating and cooling system, including humidifiers and vents. Have duct lining and insulation checked for growth.
  • Check for exhaust fans in bathrooms and kitchens. If there are no vents, do the kitchen and bathrooms have at least one window apiece? Does the cooktop have a hood vented outside? Does the clothes dryer vent outside?
  • Are all vents to the outside of the building, not into attics or crawlspaces?
    Look for obvious mold growth throughout the house, including attics, basements, and crawlspaces, and around the foundation. See if there are many plants close to the house, particularly if they are damp and rotting. They are a potential source of biological pollutants. Downspouts from roof gutters should route water away from the building.
  • Look for stains on the walls, floor or carpet (including any carpet over concrete floors) as evidence of previous flooding or moisture problems. Is there moisture on windows and surfaces? Are there signs of leaks or seepage in the basement?
  • Look for rotted building materials which may suggest moisture or water damage.
  • If you or anyone else in the family has a pet allergy, ask if any pets have lived in the home.
  • Examine the design of the building. Remember that in cold climates, overhanging areas, rooms over unheated garages, and closets on outside walls may be prone to problems with biological pollutants.
  • Look for signs of cockroaches.

Where Biological Pollutants May Be Found in the Home

  • Dirty air conditioners
  • Dirty humidifiers and/or dehumidifiers
  • Bathroom without vents or windows
  • Kitchen without vents or windows
  • Dirty refrigerator drip pans
  • Laundry room with unvented dryer
  • Unventilated attic
  • Carpet on damp basement floor
  • Bedding
  • Closet on outside wall
  • Dirty heating/air conditioning system
  • Dogs or cats
  • Water damage (around windows, the roof, or the basement)

Warning! Carefully read instructions for use and any cautionary labeling on cleaning products before beginning cleaning procedures.

Do not mix any chemical products. Especially, never mix cleaners containing bleach with any product (such as ammonia) which does not have instructions for such mixing. When chemicals are combined, a dangerous gas can sometimes be formed.

  • Household chemicals may cause burning or irritation to skin and eyes.
  • Household chemicals may be harmful if swallowed, or inhaled.
  • Avoid contact with skin, eyes, mucous membranes and clothing.
  • Avoid breathing vapor. Open all windows and doors and use an exhaust fan that sends the air outside.
  • Keep household chemicals out of reach of children.
  • Rinse treated surface areas well to remove all traces of chemicals.

Posted by Wes Diskin

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