Facts About Selecting A Water Heater

September 25th, 2013

Summary:

This fact sheet will help you select an energy-efficient water heater for your home. Many homeowners wait until their water heater fails before shopping for a replacement. Because they are in a hurry to regain their hot water supply, they are often unable to take the time to shop for the most energy-efficient unit for their specific needs. This is unfortunate because the cost of purchasing and operating a water heater can vary greatly, depending on the type, brand, and model selected and on the quality of the installation. To avoid this scenario, you might want to do some research now before you are faced with an emergency purchase. Familiarize yourself today with the options that will allow you to make an informed decision when the need to buy a new water heater arises.

Types of Water Heaters Available Within the last few years, a variety of water heaters have become available to consumers. The following types of water heaters are now on the market: conventional storage, demand, heat pump, tankless coil, indirect, and solar. It is also possible to purchase water heaters that can be connected to your home’s space-heating system.

Storage Water Heaters

A variety of fuel options are available for conventional storage water heaters electricity, natural gas, oil, and propane. Ranging in size from 20 to 80 gallons (75.7 to 302.8 liters), storage water heaters remain the most popular type for residential heating needs in the United States. A storage heater operates by releasing hot water from the top of the tank when the hot water tap is turned on. To replace that hot water, cold water enters the bottom of the tank, ensuring that the tank is always full.

Because the water is constantly heated in the tank, energy can be wasted even when no faucet is on. This is called standby heat loss. Newer, more energy-efficient storage models can significantly reduce the amount of standby heat loss, making them much less expensive to operate. To determine the most energy-efficient model, consult the EnergyGuide label required on storage water heaters. EnergyGuide labels indicate either the annual estimated cost of operating the system or energy efficiency ratings.

Demand Water Heaters

It is possible to completely eliminate standby heat losses from the tank and reduce energy consumption 20% to 30% with demand (or instantaneous) water heaters, which do not have storage tanks. Cold water travels through a pipe into the unit, and either a gas burner or an electric element heats the water only when needed. With these systems, you never run out of hot water. But there is one potential drawback with demand water heaters — limited flow rate.

Typically, demand heaters provide hot water at a rate of 4 to 6 gallons per minute. This flow rate might suffice if your household does not use hot water at more than three locations at the same time (e.g., showering, dishwasher and doing laundry simultaneously). To meet hot water demand when multiple faucets are being used, demand heaters can be installed in parallel sequence.

Heat Pump Water Heaters

Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. To heat water for homes, heat pump water heaters work like refrigerators in reverse. Heat pump water heaters can be purchased as integral units with built-in water storage tanks or as add-ons that can be retrofitted to an existing water heater tank. These systems have a high initial cost.

They also require installation in locations that remain in the 40 degree to 90 degree F (4.4 degrees to 32.2 degrees C) range year-round and contain at least 1000 cubic feet (28.3 cubic meters) of air space around the water heaters. To operate most efficiently, they should be placed in areas having excess heat, such as furnace rooms. They will not work well in a cold space.

Tankless Coil and Indirect Water Heaters

A home’s space-heating system can also be used to heat water. Two types of water heaters that use this system are tankless coil and indirect. No separate storage tank is needed in the tankless coil water heater because water is heated directly inside the boiler in a hydronic (i.e., hot water) heating system. The water flows through a heat exchanger in the boiler whenever a hot water faucet is turned on. During colder months, the tankless coil works well because the heating system is used regularly.

However, the system is less efficient during warmer months and in warmer climates when the boiler is used less frequently. A separate storage tank is required with an indirect water heater. Like the tankless coil, the indirect water heater circulates water through a heat exchanger in the boiler. But this heated water then flows to an insulated storage tank. Because the boiler does not need to operate frequently, this system is more efficient than the tankless coil. In fact, when an indirect water heater is used with a highly efficient boiler, the combination may provide one of the least expensive methods of water heating.

Solar Water Heaters

Through specially designed systems, energy from the sun can be used to heat water for your home. Depending on climate and water use, a properly designed, installed, and maintained solar water heater can meet from half to nearly all of a home’s hot water demand. Two features, a collector and a storage tank, characterize most solar water heaters. Beyond these common features, solar water-heating systems can vary significantly in design. The various system designs can be classified as passive or active and as direct (also called open loop) or indirect (also called closed loop). Passive systems operate without pumps and controls and can be more reliable, more durable, easier to maintain, longer lasting, and less expensive to operate than active systems. Active solar water heaters incorporate pumps and controls to move heat-transfer fluids from the collectors to the storage tanks. Both active and passive solar water-heating systems often require conventional water heaters as backups, or the solar systems function as preheaters for the conventional units. A direct solar water-heating system circulates household water through collectors and is not appropriate in climates in which freezing temperatures occur. An indirect system should not experience problems with freezing because the fluid in the collectors is usually a form of antifreeze. If you are considering purchasing a solar water-heating system, you may want to compare products from different manufacturers. The Solar Rating and Certification Corporation provides a benchmark for comparing the performance of some solar water heating systems.

The SRCC publishes performance ratings of both solar water-heating systems and individual solar collectors. These published ratings are the results of independent, third-party laboratory testing of these products. All systems and collectors that have been certified by the SRCC will bear the SRCC label. Keep in mind, though, that simply having an SRCC label does not imply that the product has a superior performance. Carefully compare SRCC label information on different brands and models to ensure that you are fully aware of projected performance. The Florida Solar Energy Center also provides information on solar manufacturers and contractors. It also maintains solar equipment testing facilities and publishes performance ratings for solar water heating systems. Just choosing a solar water heater with good ratings is not enough, though. Proper design, sizing, installation, and maintenance are also critical to ensure efficient system performance. Although the purchase and installation prices of solar water heaters are usually higher than those of conventional types, operating costs are much lower. For more information about solar water-heating systems, contact the Energy Efficiency and Renewable Energy Clearinghouse.

Criteria for Selection

As with any purchase, balance the pros and cons of the different water heaters in light of your particular needs. There are numerous factors to consider when choosing a new water heater. This publication has already described different system configurations. Some other considerations are capacity, efficiency, and cost.

Determining Capacity

Although some consumers base their purchases on the size of the storage tank, the peak hour demand capacity, referred to as the first-hour rating (FHR) on the EnergyGuide label, is actually the more important figure. The FHR is a measure of how much hot water the heater will deliver during a busy hour, and it is required by law to appear on the unit’s EnergyGuide label. Therefore, before you shop, estimate your household’s peak hour demand and look for a unit with an FHR in that range. Gas water heaters have higher FHRs than electric water heaters of the same storage capacity. Therefore, it may be possible to meet your water-heating needs with a gas unit that has a smaller storage tank than an electric unit with the same FHR. More efficient gas water heaters use various nonconventional arrangements for combustion air intake and exhaust. These features, however, can increase installation costs.

Rating Efficiency

Once you have decided what type of water heater best suits your needs, determine which water heater in that category is the most fuel efficient. The best indicator of a heater’s efficiency is its Energy Factor (EF), which is based on recovery efficiency (i.e., how efficiently the heat from the energy source is transferred to the water), standby losses (i.e., the percentage of heat lost per hour from the stored water compared to the heat content of the water), and cycling losses. The higher the EF, the more efficient the water heater. Electric resistance water heaters have an EF between 0.7 and 0.95; gas heaters have an EF between 0.5 and 0.6, with some high-efficiency models around 0.8; oil heaters range from 0.7 to 0.85; and heat pump water heaters range from 1.5 to 2.0. Product literature from manufacturers usually gives the appliance s EF rating. If it does not, you can obtain it by contacting an appliance manufacturer association (see Source List). Some other energy efficiency features to look for are tanks with at least 1.5 inches (3.8 centimeters) of foam insulation and energy efficiency ratings shown on the EnergyGuide labels.

Comparing Costs

Another factor uppermost in many consumers’ minds is cost, which encompasses purchase price and lifetime maintenance and operation expenses. When choosing among different models, it is wise to analyze the life-cycle cost — the total of all costs and benefits associated with a purchase during its estimated lifetime. More information on conducting life-cycle cost analyses is available from EREC. Units with longer warranties usually have higher price tags, though. Often, the least expensive water heater to purchase is the most expensive to operate.

Posted by Wes Diskin

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Ductless Exposed: The 8 Types of Ductless Systems

September 4th, 2013

NOTE: this article assumes you know what a ductless heat pump is, if you need some pre-education, click here. You can also visit my YouTube Channel for walkthrus on installed systems!

  1. Single Zone Basic (i.e: Lennox MS8)
  2. Single Zone Feature Rich (i.e.: Daikin L Series)
  3. Single Zone Specialty (i.e.: Fujitsu RLS2)
  4. 2-4 Zone Basic (i.e.: Lennox MS8 Multi)
  5. 2-4 Zone Feature Rich (i.e. Daikin MXS)
  6. 2-6/8 Zone Flex (i.e. Fujitsu HFI, Daikin RMXS Super Multi)
  7. 2-8 Zone VRV(F) (i.e Daikin VRV3-S)
  8. Radiant Heating w/ Domestic Water Heating (i.e. Daikin Altherma)

The reason why I am writing this is pretty much the same as all my other posts; too often contractors offer you a ductless system without telling you what other options are available. So, in light of this, I am going to help you understand the 8 ductless residential systems that I have listed above. Settle in, because this is going to take a few minutes!

Each of the eight has it’s own special place in this world, so let’s break them down so you can figure out what will work best in your application.

Single Zone Basic

This system is entry level ductless. You still get all the efficiency and “ductless” benefits, but usually warranty and features (like programming, etc.) are limited. If you hate your TV remote and technology in general, then this is the ductless for you! ON/OFF – HEAT/COOL. That’s it.

Single Zone Feature Rich

IF you want ductless AND you want the highest level of control, satisfaction and warranty, then a feature rich system suites you well. Things like 3D Airflow, programming, wi-fi, motion sensing, etc., etc. come built in!

Single Zone Specialty

There are 3 types of ductless buyers; those who want just efficiency (Basic), those who want efficiency and comfort (Feature Rich) and those who are disgusted by the idea of a ductless head on their wall….Specialty!!

If you are in this category  you want ductless, but dread it at the same time. The specialty system, like the Fujitsu RLS2, might be for you. Still a feature rich system, but in slick packaging! The one drawback is that the sizing is limited so I would say you are going to get up to 1200 sq ft depending on how well the house was built.

Did I mention that these are also the most efficient ductless on the market? Clocking in at 12 HSPF+, they are very much an option to consider.

2-4 Zone Basic

Remember, a multi-zone system is just one outdoor unit and multiple indoor units. Most 2-4 Zone Basic buyers are just folks who fall into the “basic” category but have a house or specific need that warrants a 2nd, 3rd or 4th head; say, the Master Bedroom needs its own cooling or the basement/upstairs needs a head for heating/cooling. Maybe the 4th head goes in the Bonus Room?

Here is a video to help.

2-4 Zone Feature Rich

Replace “basic” with “feature rich” in the paragraph above. Sorry…I’m lazy.

2-6/8 Zone Flex

This is where things start to get a little different so pay close attention. When you go to my pictures, etc. and look at ductless; do you see how each head has a line that runs from it all the way back to the heat pump? This is how the standard multi zone systems work, if you have 4 heads you have 4 lines. Now, with a Flex system 2 of those run into 1 and the other 2 run into 1 (this is called a branch), then you have only 2 lines that have to run all the way back to the Heat Pump (HP) outside. This is one difference about the Flex. The other is that the HP is a larger 4 Ton and will allow you to, say, have just 2 large 24k heads on it or all the way up to 6 smaller heads.

Another difference is that while a standard 2-4 Zone Ductless has individual control points for each head (remotes/thermostats), the Flex can be operated from a SINGLE control. This allows for better management of a full home system.

Fujitsu’s HFI System falls somewhere in between Basic and Feature Rich, but when Daikin releases the RMXS Super Multi, I have a feeling it is going to be mind-blowing, word is that it will hit 11.3 HSPF on up to 8 heads. I want it NOW!…. tantrum. 🙂

2-8 Zone VRV(F) Light Commercial

Further up and further in! This is getting a bit obscure, but it IS an option. Okay, think of the flex, but those 2 lines that came back to the Heat Pump outside go into 1 and just 1 line goes out to the HP. This is possible because the metering of refrigerant is no longer done at the HP it is done at the indoor.

Again, we do install these, but here is an application. Million Dollar Home. Everything hidden, zoned, perfect and integrated into building management software for commercial buildings…. but its a house. You see where I am going?

Radiant Heating w/ Domestic Water Heating, Cooling and Solar

That guy is obviously European!  This system has been booming in Europe for a while and is now starting to destroy Geothermal here in the northwest. Hands down, this is the system that is the one to beat in custom construction right now. Radiant Heat with Inverter Heat Pump, Cooling to Fan Coil or Head, Domestic Hot Water with Solar Optional. Man oh Man. SUMMARY: IF YOU ARE BUILDING A HOME WITH RADIANT HEATING, YOU HAVE TO ASK ABOUT THIS SYSTEM! Watch video (it starts over at about 6:20…crazy Euros). Sorry, this one just does too much stuff to describe in text.

Posted by Wes Diskin

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Variable Speed Blowers Explained!

August 31st, 2013

The best place to start may be “what is variable speed?”

“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.” Danny Heineman

As you will see in the chart above, this feature enhances every part of your heating and cooling system. Both Comfort and Savings, even your Health, is affected by having a variable speed blower in your furnace or air handler. The easiest way to explain all this is going to be by taking these one at a time, so get ready.

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, a 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.

*Note: I have a Carrier Variable Speed Furnace with the Carrier Air Purifier, read my experience on the What’s in My Home page.

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.

Posted by Wes Diskin

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Decoding Furnace Efficiencies

August 22nd, 2013

A forced air 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. If your current furnace is aging, you may want to explore when it’s time to replace your furnace to ensure you’re not overpaying for inefficient heating.

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

They provide better efficiency than outdated systems, but they may not deliver the same long-term energy savings as high-efficiency models. If you’re debating whether to replace your furnace, upgrading to at least a mid-efficiency system could help lower your heating bills without the higher upfront cost of a top-tier unit.

High-efficiency heating systems:

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

While they come with a higher initial price, the long-term fuel savings and potential rebates make them a smart investment. If you’re considering an upgrade, now is a great time to take advantage of furnace replacement savings to offset costs and improve your home’s energy efficiency.

Posted by Wes Diskin

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Selecting Heating Fuel and System Types

August 1st, 2013

Selecting the fuel and heating system best suited for your needs depends on the following factors:

  • The cost and availability of the fuel or energy source
  • The type of appliance used to convert that fuel to heat and how the heat is distributed in your house
  • The cost to purchase, install, and maintain the heating appliance
  • The heating appliance’s and heat delivery system’s efficiency
  • The environmental impacts associated with the heating fuel.

Fuel Costs

One somewhat simple way to evaluate heating options is to compare the cost of the fuel. To do that, you have to know the energy content of the fuel and the efficiency by which it is converted to useful heat.

Fuels are measured in physical units, such as gallons of oil or propane, cubic feet of natural gas, or kilowatt hours of electricity (kWh). They are also measured by heat content. In the United States, the most commonly used value for expressing the energy value or heat content of a fuel is the British thermal unit (Btu). One Btu is the amount of energy needed to raise the temperature of one pound of water 1°F, when water is at about 39°F. One “therm” is 100,000 Btu.

The chart below provides a list of typical heating fuels and the Btu content in the units that they are typically sold in the United States.

Fuel Type                 No. of Btu/Unit
Fuel Oil (No. 2)        140,000/gallon

Electricity                  3,412/kWh

Natural Gas               1,025,000/thousand cubic feet

Propane                      91,330/gallon

Wood (air dried)*      20,000,000/cord or 8,000/pound

Pellets                        16,500,000/ton

Kerosene                    135,000/gallon

Coal                           28,000,000/ton

The efficiency of the heating appliance is an important factor when determining the cost of a given amount of heat. In general, the efficiency is determined by measuring how well an appliance turns fuel into useful heat. (The condition of the heat distribution or delivery system also affects the overall system efficiency.) Many types of space heating appliances must meet minimum standards for efficiency developed by the U.S. Department of Energy. This next chart provides average efficiencies for common heating appliances.

Environmental and Efficiency Considerations

In addition to cost, you might consider the environmental impact of your heating fuel. You probably generate more greenhouse gases by heating and cooling your home than by any other activity, including driving.
Burning natural gas, oil, propane, wood, or pellets in your home with a high-efficiency furnace or boiler can be a very efficient way to deliver heat to your home. Of all these choices, natural gas burns cleanest.
In the NW, due to hydro power, using a heat pump is one of the most cost effective and clean ways to heat your home.

Of course, the cleanest fuel for heating your home is solar energy, which produces no pollution at all. In most homes, solar energy will merely supplement the main heating and cooling source, although many are building homes that aim to consume net zero energy over the course of a year.

Choosing a Heating and Cooling System

When choosing a heating and cooling system, there is no one answer; it’s largely a personal choice. For existing systems, your choices are pretty much set by the limitations of replacing the system with something significantly different. But for a new home, if your building contractor doesn’t impose limitations, the choices are wide open.

Choosing between systems depends in part on your fuel options, but also on your preferences. Here are some questions you might consider:

  • Do you want a central air conditioning system? If so, are any heat pump options—particularly geothermal heat pumps—practical for your home?
  • If you don’t want central air conditioning, could a baseboard hot water system or a radiant heating system meet your needs?
  • If you need to cool your home but don’t want a central air conditioning system, could a room air conditioner, or a ductless mini-split system meet your needs?

Answering these questions, and exploring the information in the heating, cooling, and heat pump sections of this Web site, should lead you to an answer

Posted by Wes Diskin

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Understanding Heat Pump Efficiency

July 23rd, 2013

Heat pumps can be much more efficiency than other systems. Here in the Northwest, a heat pump can have an efficiency starting at 300%, while electric heating systems have an efficiency of 100%. Oil heat systems range in efficiency from 50% to 85%. Natural gas systems range in efficiency from 50% to 95%.

The efficiency of a heat pump is indicated by Coefficient of Performance or COP. The COP is the ratio of what you get in heat energy from the heat pump divided by what you pay for in electric energy to provide that heat. For example, a COP of 3.0 means for every dollar’s worth of heat delivered to your home, you only need to buy $0.33 worth of electricity. With standard heat pumps, as the outdoor temperature decreases, the efficiency and COP of a heat pump decreases. When the outdoor air temperature is 47 degrees, many heat pumps work with COPs in the range of 3 to 3.8. At 17 degrees, COPs are typically 2.8 to 3.4. The higher the COP, the more efficient the heat pump.

In the Pacific NW, a properly sized and well-installed heat pump will have an average COP of 2.75 over the course of a heating season. (Based on Base Model Efficiency)

There are other factors which reduce the efficiency of a heat pump throughout the heating season. For instance, a heat pump’s outdoor coils periodically need to be defrosted. This is done by reversing the cycle of the heat pump so that the heat from the house thaws the ice accumulated on the coils.

Efficiency is further reduced whenever the back-up heating system is used. This back-up system can be electric, natural gas or oil and is required during times when the outside temperature is so low that the heat pump is not able to provide enough heat for the house. This is called the balance point.

Heat pumps are also rated by a measurement call the Heating Seasonal Performance Factor (HSPF), which estimates the heat output relative to the energy consumed for the entire heating season. The higher the HSPF the less energy you will need to operate the heat pump. An HSPF of 8 corresponds approximately to an average COP of 3.

Posted by Wes Diskin

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Understanding Efficiency Ratings of Furnaces

July 18th, 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 Is Where The Heart Is

July 14th, 2013

Home improvements don’t have to be expensive and drastic to make a difference in your home. Make a happier home with small changes that make a big impact.

Adding in new pieces of furniture, tweaking the lighting and tossing a blanket on the couch are all simple ideas that can make your home a more comfortable place to be. These changes create an opportunity to bring more beauty into your home.

To make the change most relevant to you, decide which room or area of your house is your favorite place to be. Is it your bed? Your kitchen? Patio?

If its your bed, pick out pillows and blankets that have it feeling like heaven. Home Beautiful offers 5 Tips for Choosing Bed Linens . Even if you make these changes one-by-one you will notice the difference, whether it be through comfort or aesthetics.

If you’re a wiz in the kitchen, put up your favorite art or bring in comfy furniture.  In another Home Beautiful article you will find 10 Interior Designers Share Their Kitchen Style. Each designer’s advice is to accommodate your personal style and needs depending on the function of the space.

It doesn’t stop with the inside of your house; Add a fire pit and twinkling lights to your backyard, take the time to do some landscaping, put up colorful shades in the guest bedroom. Whatever your project may be remember the home is where the heart is, so bring the things you love the most into your home.

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‘Right Sizing’ Heat Pumps for the Pacific Northwest

July 12th, 2013

Sizing is one of the most important factors determining a heat pump’s efficiency and reliability. In Western Washington, heat pumps are sized according to the heating requirements of your home. If you lived in a climate where heat pumps are primarily used for air conditioning, then you homes cooling needs would determine the size of the heat pump.

In order to determine size, we must do a heat loss for your home as well as analyse your home’s duct sizing to determine air circulation requirements. For a proper installation these calculations must be done. This helps us “balance” the system to ensure that the heat pump delivers the correct amount of air to all rooms in the house.

Heat pumps are sized in two ways; tone and BTUs. Tons do not refer to the weight of the heat but rather are a measure of cooling capacity. Each ton of heat pump capacity produces about 12,000 BTUs of heat. A BTU is a measure of heat output; most heat pumps are in the 24,000 to 60,000 BTU range or 2 to 5 ton range.

As the temperature outside drops, the ability of most heat pump systems (except inverter) to deliver heat also drops somewhat and the heat needs of the house go up. It is possible to install a system large enough to heat the house no matter how low the temperature is outside. But a system which is sized to heat your home during the coldest day of the year will be over sized the rest of the year. This is not only uneconomical, but also places unnecessary stress on the compressor because the heat pump cycles on and off constantly.

In the Pacific NW’s maritime climate, a heat pump should be sized so that it can heat the house when outside temperatures are as low as 30 degrees, below that you will need to invest in a 2-stage or Modulating Heat Pump.

Posted by Wes Diskin

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Three Grades of Radiant Floor Installation

June 19th, 2013

Radiant heat has long been touted as the what’s what of heating. In many custom homes it is the one thing that the new homeowners are the most proud of. Not only has it become the signature system for ultimate comfort, but it is also a buzz word that many have cashed in on by installing what can only be described as “ghetto radiant”; which has inspired me to bring you this article.

The first of these grades is what I call “ghetto radiant”. This is the use of a traditional hot water tank system to heat the water that is run through the floors.

The worst part is that the water going into the floor is brought back to your water tank and then you are free to use it to wash your dishes or take a shower in. Some authorities permit this so long as the heater is used for both domestic and space heating. However, water heaters used for radiant space heating operate in the temperature range where bacteria, such as Legionella, develop.

To prevent this, the water heater must be run continuously in the range of 140 degrees Fahrenheit or higher, and the radiant system must be cycled periodically, regardless of the need for heating. This operating temperature then forces the use of scald protection valves on the domestic side and mixing valves on the heating side. As is often the case, trying to make the systems more affordable and simpler actually results in more complications and hazards.

Also, this type of radiant heat often relies on fresh air vents in the windows to bring in cold, un-tempered air by installing a timer on a fan in the utility room. Translation: Bare –bones, but to code, ventilation that will lead to the stalest air you have ever tasted. Most of these systems are only one zone, so balancing the in-floor loops and getting even heat throughout the house is a nightmare. My family and I lived in one of these homes for one year while our house was being built; let me just say I feel sorry for the next tenant! Being a heating expert and not being able to do any upgrades also drove me nuts, but I digress.

The second level is the “tank less two step”. This would be similar to the “ghetto”, but instead of a horribly inefficient standard hot water tank, it will come with a high efficiency on-demand water heater, such as a Rinnai. The installation of the floor loops and ventilation may stay the same, so while you gain some efficiency; this type is really a wolf in sheep’s clothing. Tank less water heaters, such as a Rinnai, were meant for heating domestic hot water, not your house. When they are used in this application, the manufacturer cuts all your warranties in half, which isn’t really a great sign.

The third level can be best described as, well, the “Right Way”. I don’t have anything clever for this one; let’s just say it leads to happiness and satisfaction. What you have here is a high efficiency heat source such as a wall mount boiler (not water heater) or heat pump that heats the water for the radiant system and domestic hot water, however, this is a closed loop application so the water in the system never touches the water you shower in! Almost all of these applications are heavily zoned to give you maximum comfort control in every living space of the home. Domestic water is heated in an indestructible in-direct fired water tank (heat exchanger) and Ventilation is provided through a Heat Recovery or Energy Recovery Ventilator so all fresh air coming into the house is both filtered and then heated by stale air leaving the house.

One of the most important decisions you can make is choosing the heating company that will install your system. We are generally always high when it comes to install compared to most of our competitors, but it is not just dollars. We have the highest paid technicians, the highest level of design credentials, the highest level of customer satisfaction, the largest service department and the best guarantee, your 100% satisfaction!

It is very important that when you are shopping for a home or building one with radiant heating, you ask about these three simple things.

  • Heat Source – Is it a water tank, on-demand water heater, boiler or heat pump? What efficiency?
  • Zoning – Single Zone or Multiple Zoning?
  • Ventilation – Window/Wall Ports or HRV/ERV?

Posted by Wes Diskin

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