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‘Heating’
An R-value indicates an insulation’s resistance to heat flow. the higher the R-value, the greater the insulating effectiveness.
The R-value depends on the type of insulation and includes it’s material, thickness, and density. When calculating the R-value of a multilayered installation, add the R-values of the individual layers. Installing more insulation in your home increases the R-value and the resistance to heat flow.
The effectiveness of an insulation’s resistance to heat flow also depends on how and where the insulation is installed. For example, insulation that is compressed will not provide its full rated R-value. The overall R-value of a wall or ceiling will be somewhat different from the R-value of the insulation itself because some heat flows around the insulation through the studs and joists. Therefore, it’s important to properly install your insulation to achieve the maximum R-value.
The amount of insulation or R-value you’ll need depends on your climate, type of heating and cooling system, and the section of the house you plan to insulate.
Properly insulating air ducts located in unconditioned spaces such as attics, crawl spaces, garages, or unfinished basements can help improve your home’s energy efficiency.
Air ducts supply conditioned air from your space heating and cooling equipment to your living spaces. They also return an equal volume of air back to the equipment to be conditioned again.
Ducts are typically made out of thin metal materials that easily conduct heat. Therefore, uninsulated or poorly insulated ducts in unconditioned spaces can lose through conduction 10%–30% of the energy used to heat and cool your home. The heating and cooling equipment then has to compensate for the heat loss and gain by conditioning additional air. This added conditioning raises a homeowner’s energy bills. In addition, when ducts lose heat through conduction, rooms served by long duct runs can experience “cold blow” during the winter because they usually have lower heating-supply temperatures.
Ducts in conditioned spaces experience minimal conductive losses and gains since they are exposed to indoor air temperatures. However, these ducts may also require some insulation to prevent condensation on duct walls and to ensure that conditioned air is delivered at the desired temperature.
HVAC contractors typically insulate ducts using rigid fiber board insulation. Below is a table showing the recommended R-values by climate for duct insulation in unconditioned spaces.
Older space conditioning systems (more than 10 years old) are often unreliable and much less efficient than a modern system. When it’s time for a new replacement, choosing one of the correct size (heating and/or cooling output) is critical to getting the best efficiency, comfort, and lowest maintenance and operating costs over the life of the new system. Some national surveys have determined that well over half of all HVAC contractors do not size heating and cooling systems correctly.
The most common sizing mistake is in oversizing. This not only makes the new system more expensive to install, but also forces it to operate inefficiently, break down more often, and cost more to operate. Oversized heating equipment also often creates uncomfortable and large temperature swings in the house. Oversized air conditioners (and heat pumps) do not run long enough to dehumidify the air, which results in the “clammy” feeling and unhealthy mold growth in many air-conditioned houses (see dehumidifying heat pipes as one solution to this problem).
Incorrect Sizing Methods
It is the installer/contractor’s job to perform the correct sizing calculation for the building. However, many installers only check the “nameplate” (the label on the unit that has the Btu per hour output among other things) of the existing system and sell you one just like it, or even worse, one that’s larger. This is a not a correct sizing method and not in your best interests! Other methods include simple “rules of thumb” based on the size of your home or using a chart that accounts for a variety of factors. While these methods might provide a first estimate, they should not be used to size your system.
Why Most Older Systems are Oversized
Before the era of tightly constructed homes, it was not uncommon to install furnaces and air conditioners that had two to four times the necessary capacity. Since many people have added new windows, caulking, weather-stripping, and insulation to their homes, going by the nameplate is likely to result in an oversized system. Making improvements such as these to reduce heat loss in the winter and heat gain in the summer should allow you to install a smaller systems while still being comfortable, as well as saving large amounts of energy.
Manual J and Manual D: The Correct Way to Size a System
Correct system sizing requires considering many factors other than simply reading the nameplate of the existing unit. Key factors for correctly sizing a heating and cooling system include the following:
- The local climate
- Size, shape, and orientation of the house
- Insulation levels
- Window area, location, and type
- Air infiltration rates
- The number and ages of occupants
- Occupant comfort preferences
- The types and efficiencies of lights and major home appliances (which give off heat).
Homeowners should insist that contractors use a correct sizing calculation before signing a contract. This service is often offered at little or no cost to homeowners by gas and electric utilities, major heating equipment manufacturers, and conscientious heating and air conditioning contractors. Manual J, “Residential Load Calculation,” published by the Air Conditioning Contractors of America (ACCA), is the recommended method for use in the United States. There are also many user-friendly computer software packages or worksheets that can simplify the calculation procedure. You should make sure that the procedure used by the contractor follows Manual J.
If ducts are part of the installation, they should be sized using the ACCA’s Manual D, “Residential Duct Design.” The ACCA also offers a comprehensive guide for choosing home heating and cooling systems, called Manual S, “Residential Equipment Selection.”
A Special Case: Sizing Steam Heating Systems
One exception to the above is in steam heating systems. For these systems, the boiler should be sized to match the radiators. However, there is still room for energy savings. First of all, the original boiler may be oversized for the radiators, so the contractor shouldn’t just order the same capacity boiler, but instead should match the boiler to the radiators. Second, if you’ve increased the energy efficiency of your home, it may have more radiators than it needs.
It may be possible to remove radiators in the core of the house and shift the others around, replacing larger radiators with smaller ones. Since radiators are modular, it is theoretically possible to downsize a radiator by removing sections; in practice, this is usually difficult to do without damaging them. In many parts of the country, used radiators are available cheaply, so you can potentially buy small radiators to replace large radiators; if you do so, be prepared to replace the shutoff valves as well, since they often won’t match. Newly manufactured steam radiators are available as well.
In any case, you should work with a heating and cooling professional when downsizing your system. Your house’s heating needs should be calculated using Manual J, and your radiators should be downsized appropriately. Match the new boiler to the remaining radiators. Note that balancing steam heating systems is more an art than a science; ideally, you will find a heating professional with experience in steam heating systems.
Steps a Good Contractor Should Take to Size Your System
Many factors affect a home’s heating or cooling requirement, or “load.” A good estimator will measure walls, ceilings, floor space, and windows to determine the room volumes, and will assess the R-value of the home’s insulation, windows, and building materials. A close estimate of the building’s air leakage is also necessary. A blower door test is the best way to measure air leakage.
A good estimate will also include an inspection of the size, condition of seals on joints and insulation, and location of the distribution ducts in forced air systems. The placement of supply and return registers should be appropriate for the system type and size.
The orientation of the house also affects heat gain and heat loss through windows. Overhangs can reduce solar gain through windows. Make sure the contractor uses the correct design for the outdoor temperature and humidity in your area. Using a higher summer design temperature results in oversizing air conditioners.
When the contractors are finished, get a copy of their calculations, assumptions, and the computer printout or finished worksheet. This is your only proof that they did the job right. To summarize, when designing your new heating and air conditioning system, the contractor you choose should do the following:
When replacing an existing heating and cooling system, it’s important to first consider the limitations imposed by your current system. Of course, it is possible to install virtually any heating and cooling system in any house, but the cost and aesthetic impacts may be unacceptable for you. When selecting a heating and cooling system for a new house, your options are generally much wider, although your builder or developer may place limitations on your choices.
For both new and existing homes, it’s important to first maximize the energy efficiency of your home. This is the most cost-effective means of keeping your home comfortable, no matter what climate you live in. After doing so, be sure to do what you can to make use of passive solar heating in your home and consider whether ventilation can keep your house cool on warm days, or if you really need artificial cooling. Only after exploring these topics should you decide on the type of system you want and work with a contractor to figure out the optimum size for it. To learn more on these topics, see the following resources:
Even the most energy-efficient heating and cooling system will fail to save you money if it is installed incorrectly or improperly adjusted. To verify the qualifications of your heating and cooling contractor, ask if they have been certified by North American Technician Excellence, Inc. (NATE).
Here are some further tips on choosing contractors:
- Ask neighbors and friends if they have worked with a contractor they would recommend
- Focus on local companies
- Look for licensed, insured contractors
- Ask about previous experience
- Check references
- Inquire with the Better Business Bureau.
Use these methods to select several contractors, then get at least three detailed, written bids. Each bid should include an agreement to provide written calculations (listing the procedures and standards that will be followed), equipment and installation warranties, a payment schedule, and a firm completion date. Avoid making your decision solely on the basis of price. The quality of the installation should be your highest priority, because quality will determine energy cost, comfort, and durability.
Heating and cooling your home uses more energy and drains more energy dollars than any other system in your home. Typically, 44% of your utility bill goes for heating and cooling. No matter what kind of heating, ventilation and air-conditioning system you have in your house, you can save money and increase comfort by properly maintaining and upgrading your equipment. Remember, though, an energy efficient furnace or air-conditioner alone will not have as great an impact on your energy bills as using the whole house approach. By combining proper equipment maintenance and upgrades with appropriate insulation, weatherization and thermostat setting, you can cut your energy bills in half.
All major appliances including gas furnaces, boilers, air conditioners and heat pumps sold in California meet the Title-24 energy efficiency “standards.” If you are thinking about purchasing a new central furnace, please check out our Appliance Database that lists the most energy-efficient models. This database will eventually be interactive allowing you to compare models.
Heating Tips
- Set your thermostat as low as it is comfortable.
- Clean or replace filters on furnaces once a month.
- Clean warm-air registers, baseboard heaters and radiators as needed; make sure they’re not blocked by furniture, carpeting or drapes.
- Use kitchen, bath and other ventilating fans wisely; in just one hour, these fans can pull out a houseful of warmed or cooled air. Turn fans off as soon as they have done the job.
- Keep draperies and shades open on south-facing windows during the heating season to allow sunlight to enter your home; close them at night to reduce the chill you may feel from >cold windows.
- Close an unoccupied room that is isolated from the rest of the house such as in a corner and turn down the thermostat or turn off the heating for that room or zone. Do not, however, turn the heating off if it adversely affects the rest of your system.
Heat Pumps
If you use electricity to heat your home, consider installing an energy efficient heat pump system. Heat pumps are the most efficient for of electric heating in moderate climates, providing three times more heating than the equivalent amount of energy they consume in electricity. There are three types of heat pumps: air-to-air, water source and ground source. They collect heat from the air, water or ground outside your home and concentrate it for use inside. Heat pumps do double duty as a central air conditioner. They can also cool your home by collecting the heat inside your house and effectively pumping it outside. A heat pump can trim the amount of electricity you use for heating as much as 30% to 40%.
Heat Pump Tips
- Do not set back the heat pump’s thermostat manually if it causes the electric resistance heating to come on. This type of heating, which is often used as a backup to the heat pump, is more expensive.
- Clean or change filters once a month or as needed and maintain the system according to manufacturer’s instructions.
Gas and Oil Systems
Gas furnaces are rated for efficiency with an Annual Fuel Utilization Efficiency number, or an AFUE. According to the state’s Energy Efficiency Standards, Title 24, the minimum AFUE for central furnace systems now sold in California is 0.78, which means that 78 percent of the fuel used by the furnace actually reaches your home’s duct work as heat.
The higher the AFUE, the more efficient the furnace. AFUE numbers in today’s furnaces range from 0.78 to around 0.90. If you are thinking about purchasing a new central furnace, please check out our Appliance Database that lists the most energy-efficient models.
Gas Furnace Tips
- Don’t block registers, vents or heating units with furniture or drapes. That makes your furnace work harder and uses more energy.
- Consider installing a programmable thermostat. You can save as much as 10% a year on your heating and cooling bills by simply turning your thermostat back 10% to 15% for 8 hours with an automatic setback or programmable thermostat.
- Using a programmable thermostat you can adjust the times you turn on the heating or air-conditioning according to a pre-set schedule. As a result, you don’t operate the equipment as much when you are asleep or when the house or part of the house is not occupied. Programmable thermostats can store and repeat multiple daily setting (six or more temperature setting a day) that you can manually override without affecting the rest of the daily or weekly program. When purchasing a new thermostat, look for the ENERGY STAR label (www.energystar.gov) and one that allows you to easily use two separate programs; an “advanced recovery” feature that can be programmed to reach the desired temperature at a specific time; and a hold feature that temporarily overrides the setting without deleting preset programs.
Air Conditioners
It might surprise you to know that buying a bigger room air-conditioning unit won’t necessarily make you feel more comfortable during the hot summer months. In fact, a room air conditioner that’s too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit. This is because room units work better if they run for relatively long periods of time than if they are continually, switching off and on. Longer run times allow air conditioners to maintain a more constant room temperature. Running longer also allows them to remove a larger amount of moisture from the air, which lowers humidity and, more importantly, makes you feel more comfortable.
Sizing is equally important for central air-conditioning systems, which need to be sized by professionals. If you have a central air system in your home, set the fan to shut off at the same time as the cooling unit (compressor). In other words, don’t use the system’s central fan to provide circulation but instead use circulating fans in individual rooms.
SEER is the Seasonal Energy Efficiency Rating. SEER rates the efficiency during the cooling season. Look for a SEER rating of 13 or above.
Evaporative Coolers
Evaporative coolers may be installed as an alternative to air conditioning, particularly in climates with very dry air. Evaporative coolers provide mechanical cooling to a building by either direct contact of air with water (direct evaporative cooler) or a combination of a first-stage heat exchanger to pre-cool the air and a second stage with direct air contact with water (indirect/direct evaporative cooler).
Cooling Tips
- Whole house fans help cool your home by pulling cool air through the house and exhausting warm air through the attic. They are effective when operated at night and when the outside air temperature is cooler than the inside.
- Set your thermostat as high as comfortably possible in the summer. The less difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.
- Don’t set your thermostat at a colder temperature setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and therefore unnecessary expense.
- Set the fan speed on high except in very humid weather. When it’s humid set the fan speed on low. You’ll get better cooling.
- Consider ceiling fans to spread the cooled air more effectively through your home without greatly increasing your power use.
- Don’t place lamps or TV sets near your air conditioning thermostat.
- Plant trees or shrubs to shade air-conditioning units but not to block the airflow. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.
Heating bills across the country are the highest they have ever been, with out any relief in sight. Even if your older furnace runs, from an economic standpoint it would be wise to replace it. With the proper furnace selection, your central air-conditioning bills can be lower too.
Compared with a 17-year-old furnace, a new furnace can save the typical family hundreds of dollars per year. Based on the efficiency of your old furnace, probably 60% at best, a new furnace can cut your utility bills by 40%. You can do the arithmetic to determine your annual savings.
Not only will you have lower utility bills, but the comfort and quiet operation of a new system will surprise you. The contractor should install a computerized thermostat with it. This thermostat, coupled with the electronic controls in the new furnace, will maintain even room temperatures.
You can choose from two basic designs of furnaces: condensing and non-condensing. The condensing models (this refers to the type of heat exchanger used) are the most efficient and the best choice for most homeowners. The efficiencies of condensing models range from about 90% to over 95%.
These models are very efficient, and so little heat is lost in the flue gases that a chimney is not needed. The gases are exhausted by a 2-inch-diameter plastic pipe through an outdoor wall. With no need for a new chimney liner, a condensing furnace is often cheaper to install.
Some models also offer sealed combustion for better efficiency. The combustion air is drawn in from outdoors through another plastic pipe instead of being drawn from inside your house. Being sealed, there are fewer indoor drafts, less noise and less chance of hazardous back drafting.
For the ultimate in comfort and efficiency, but at a higher initial cost, is a two-stage heat output furnace with a variable-speed blower. This type of blower is needed if you want the best central air-conditioning.
In all but the coldest weather, the gas burners operate at a low heat level. This allows the furnace to run more continuously with fewer uncomfortable on/off cycles. The blower also runs slower and quieter at this low level. During very cold weather, it automatically switches to high heat.
If your budget allows, also install a quality air cleaner. Since a two-stage unit runs more, the air cleaner is more effective for allergy sufferers.
As much as half of the energy used in your home goes to heating and cooling. So making smart decisions about your home’s heating, ventilating, and air conditioning (HVAC) system can have a big effect on your utility bills — and your comfort. Take these steps to increase the efficiency of your heating and cooling system. For more information, see our Guide to Energy Efficient Heating & Cooling
1. Change your air filter regularly
Check your filter every month, especially during heavy use months (winter and summer). If the filter looks dirty after a month, change it. At a minimum, change the filter every 3 months. A dirty filter will slow down air flow and make the system work harder to keep you warm or cool — wasting energy. A clean filter will also prevent dust and dirt from building up in the system — leading to expensive maintenance and/or early system failure.
2. Tune up your HVAC equipment yearly
Just as a tune-up for your car can improve your gas mileage, a yearly tune-up of your heating and cooling system can improve efficiency and comfort.
Maintain your equipment: A Checklist
Finding the right contractor: 10 Tips
3. Install a programmable thermostat
A programmable thermostat is ideal for people who are away from home during set periods of time throughout the week. Through proper use of pre-programmed settings, a programmable thermostat can save you about $150 every year in energy costs.
4. Seal your heating and cooling ducts
Ducts that move air to-and-from a forced air furnace, central air conditioner, or heat pump are often big energy wasters. Sealing and insulating ducts can improve the efficiency of your heating and cooling system by as much as 20 percent — and sometimes much more.
Focus first on sealing ducts that run through the attic, crawlspace, unheated basement, or garage. Use duct sealant (mastic) or metal-backed (foil) tape to seal the seams and connections of ducts. After sealing the ducts in those spaces, wrap the ducts in insulation to keep them from getting hot in the summer or cold in the winter. Next, seal ducts that you can access in the heated or cooled part of the house.
See our Duct Sealing brochure  (1.13MB) for more information.
5. Consider installing ENERGY STAR qualified heating and cooling equipment
If your HVAC equipment is more than 10 years old or not keeping your house comfortable, you should have it looked at by a professional HVAC contractor. If it is not performing efficiently or needs upgrading, consider replacing it with a unit that has earned the ENERGY STAR. Installed correctly, these high-efficiency heating and cooling units can save up to 20 percent on heating and cooling costs. But before you invest in a new HVAC system, make sure that you have addressed the big air leaks in your house and the duct system. Sometimes, these are the real sources of problems rather than your HVAC equipment.
Remember that getting the proper size and a quality installation is essential to getting the most from your new equipment. When replacing HVAC equipment, bigger doesn’t always mean better. If the unit is too large for your home, you will be less comfortable and might actually have higher utility bills. Oversized equipment will operate in short run cycles, not allowing the unit to reach efficient operation and remove humidity from the air — resulting in an uncomfortable home. Your contractor should determine the right size for your HVAC equipment by using ACCA/ANSI Manual J or an equivalent sizing calculation tool that takes into account specific information about your home.
In order to make a room comfortable in hot, humid climates, an air conditioner must lower the indoor humidity level as well as the air temperature. If an air conditioner fails to lower the humidity adequately, the air will be cool, but will feel uncomfortably damp. Inappropriately sized air conditioners are prone to this problem; large units quickly cool the air, but cycle off before they can properly dehumidify it. In extremely humid climates, even correctly sized air conditioning equipment could fail to maintain a home at a comfortable humidity level.
One technology that addresses this problem is the dehumidifying heat pipe, a device that enables an air conditioner to dehumidify better and still efficiently cool the air. The heat pipe is ideal for hot, humid environments.
A dehumidifying heat pipe resembles two heat exchangers, located on either side of the air conditioner’s evaporator coil. Several tubes connect the two sections. A refrigerant (usually an HCFC) inside the tubes pre-cools the incoming supply air by absorbing the heat from it. This causes the refrigerant in the tube to evaporate. The air conditioner evaporator cools it further, extracting up to 91% more water vapor than a conventional evaporator would. After the refrigerant in the tubes changes into a vapor, it flows to the condensing section at the other end of the system. There, it releases its heat into the air stream and returns to its liquid state again. Gravity then causes the refrigerant to flow to the evaporator end of the pipe to begin the cycle again.
Most models of heat pumps and central air conditioners can be retrofitted with dehumidifying heat pipes. You can choose either a replacement cooling coil that incorporates the heat pipe, or add-on heat pipes for the unit’s ventilation system. You may also want to consider a complete air-conditioner unit that incorporates the heat pipe.
Although the heat pipes don’t use any electricity directly, they cause the conditioned air to leave the system slightly warmer than it would have in the absence of the heat pipe, so it takes more energy to cool your home. The system also consumes more fan power to blow air past the heat pipe. However, the manufacturer claims that your thermostat can be set higher with the low humidity air, allowing a net energy savings.
Limitations When Replacing Existing Heating Systems
In an existing home, it’s important to consider the impacts of replacing your current heating system with a different type of heating system. The easiest route is simply to replace your furnace or boiler with an updated model of the same type, but this may keep you from your most efficient heating and cooling options. Here’s what you need to consider in the following situations:
Switching Electric Resistance or Steam Heating to Hot Water Heating
Electric resistance heating, also called electric baseboard heating, is the cheapest to install and the most expensive to operate, as it is the least efficient source of heat. Unfortunately, upgrading to ducted systems, as discussed below, will involve a significant expense for ducting. Another option is to switch to a hot water baseboard system. Baseboard heaters can probably replace electric resistance baseboards in the same location, but will still require extensive plumbing.
Steam systems are generally less efficient than hot water heating systems, but the efficiency gain of upgrading to hot water is probably not worth the expense; it would be better instead to upgrade or replace your boiler. However, it is sometimes possible to convert existing steam distribution pipes to hot water heating, which reduces the cost of the system to the cost of the boiler, the baseboard heaters, and the installation labor. This is generally only feasible in newer two-pipe steam systems (that is, systems in which two pipes go to each radiator, one for the steam and one for the condensate return). For some homeowners, the aesthetic and space-saving benefits of eliminating the large steam radiators may be worth the expense.
Switching Among Ducted Heating and Cooling Systems
If you currently own a forced-air heating system, you may wish to add central air conditioning (if you don’t have it already) or switch to a heat pump system. Adding central air conditioning is fairly simple, but be sure your contractor matches the system to your existing ductwork. Switching to a heat pump system could be problematic, since heat pumps generally require larger ducts. However, many heating systems are oversized, particularly if your home is well insulated. It may be feasible to upgrade the energy efficiency of your home (if it hasn’t been upgraded already) and convert to a smaller-capacity heat pump that is matched to your existing ductwork. To evaluate this option, consult a heating and cooling professional.
Heat pumps are among the most efficient sources of heating and cooling, but in areas with high electricity costs, they may still be more expensive than other options. Switching from a heat pump system to a furnace system (possibly with a central air conditioner) is feasible but probably not cost effective. However, if you wish to do so, the ducts should have no problem accommodating the new system, assuming it is sized correctly.
Adding Ducts to Your Home
Many homes that use steam or hot water heating, radiant heating, or electric resistance heating (or have no heating at all) do not have ducts. Homeowners may want to add ducts to their homes for a number of reasons, but the most common reason is to provide central air conditioning. If that’s your only reason for wanting to add ducts, consider instead adding a ductless mini-split air conditioner or ductless mini-split heat pump.
If you are considering switching from your current system to a ducted system simply to upgrade your heating system’s efficiency, it probably is not worth it, except perhaps for electric resistance heating. Instead, you should look into upgrades to your existing system (see the heating section for more information). For steam systems and electric resistance heating, consider switching to hot water baseboard heating, as discussed below.
Adding ducts to an existing home can be a difficult proposition. In a single-story ranch home with an unfinished basement or crawl space, the ducts could be located underneath the main living space, and nearly any ranch home could accommodate ducts in the attic space. In homes with high ceilings, it may be possible to hide the ducts in a dropped ceiling. In all cases, DOE’s Building America program recommends that the ducts be located within the home’s conditioned space, even if that means extending to conditioned space into the crawlspace or the attic. See the section on ducts for more information.
In multi-level homes, or single-story homes with finished basements and attics, the logistics of adding standard ducts are nearly insurmountable, unless you plan to largely gut the home as part of a remodel. Fortunately, there is an alternative: several companies now offer “mini-duct” air distribution systems that force air through plastic feeder ducts that are only 2 inches in diameter. These ducts can be easily threaded through cavities in walls, floors, and ceilings.
A downside with mini-ducts is that they general require more outlets: roughly 5 outlets per ton of cooling, or one outlet for every 2400 BTUs of heating. This will likely result in higher costs to install the system. The Air Conditioning and Refrigeration Institute (ARI) certifies high velocity air distribution systems for use with numerous heat pumps, air conditioners, and heat sources. For more information, see the “Product Info” category in the “Learn More” section at right.
If you add ducts to an existing home, the question is whether to continue using your existing heating system or to install a new forced-air heating system. For homes using electric resistance heating, adding either a furnace or heat pump is clearly preferable. With steam, hot water, or radiant heat, the decision is less obvious: it really depends on how efficient your current system is, how efficient the new system would be in the heating mode, and the cost difference between installing just a central air conditioner versus installing both a heating and cooling system. A heating and cooling professional should be able to help you evaluate these options.
Note that changing to a forced-air system has its pluses and minuses. On the plus side, not only does it allow for central air conditioning, but the furnace could be much more efficient than your current heating system. On the negative side, the fan for the forced air system could increase your use of electricity significantly. This may be an important consideration in areas with high electricity prices.
Maintain your equipment to prevent future problems and unwanted costs. Keep your cooling and heating system at peak performance by having a contractor do annual pre-season check-ups. Contractors get busy once summer and winter come, so it’s best to check the cooling system in the spring and the heating system in the fall. To remember, you might plan the check-ups around the time changes in the spring and fall.
A typical maintenance check-up should include the following.
- Check thermostat settings to ensure the cooling and heating system keeps you comfortable when you are home and saves energy while you are away.
- Tighten all electrical connections and measure voltage and current on motors. Faulty electrical connections can cause unsafe operation of your system and reduce the life of major components.
- Lubricate all moving parts. Parts that lack lubrication cause friction in motors and increases the amount of electricity you use.
- Check and inspect the condensate drain in your central air conditioner, furnace and/or heat pump (when in cooling mode). A plugged drain can cause water damage in the house and affect indoor humidity levels.
- Check controls of the system to ensure proper and safe operation. Check the starting cycle of the equipment to assure the system starts, operates, and shuts off properly.
Cooling Specific
- Clean evaporator and condenser air conditioning coils. Dirty coils reduce the system’s ability to cool your home and cause the system to run longer, increasing energy costs and reducing the life of the equipment.
- Check your central air conditioner’s refrigerant level and adjust if necessary. Too much or too little refrigerant will make your system less efficient increasing energy costs and reducing the life of the equipment.
- Clean and adjust blower components to provide proper system airflow for greater comfort levels. Airflow problems can reduce your system’s efficiency by up to 15 percent.
Heating Specific
- Check all gas (or oil) connections, gas pressure, burner combustion and heat exchanger. Improperly operating gas (or oil) connections are a fire hazard and can contribute to health problems. A dirty burner or cracked heat exchanger causes improper burner operation. Either can cause the equipment to operate less safely and efficiently.
Actions to Do Yourself
- Inspect, clean, or change air filters once a month in your central air conditioner, furnace, and/or heat pump. Your contractor can show you how to do this. A dirty filter can increase energy costs and damage your equipment, leading to early failure.
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