Priority One: Energy Efficiency:
If you’re like most people, a little more than half of your energy budget goes toward heating your home in winter. A properly maintained heating system, especially in a house that is already oriented toward energy efficiency, can save you serious money.
Types of Systems
There are different types of central home heating systems: forced warm air heating and hydronic heating, which uses steam or hot water. Whether you are considering the installation of a complete new system or are just replacing a component of your present system, it is a good idea to become familiar with each system and the different types of fuel available.
To provide the most comfort and value, a furnace must be sized properly for the house in which it is to be installed. An oversized unit will cycle frequently, causing great variations in room temperature. An undersized unit may not provide sufficient heat to make your home comfortable.
How Different Heating Units Work
- Forced Warm Air Heat: Forced air ducted heat uses a blower in conjunction with a ductwork system to circulate warm air throughout the home. A blower pushes heated air through the ductwork into the various rooms through registers or diffusers. As the air cools off it drops and moves to the return air grilles and is pulled back to the blower by way of the return air ductwork. The furnace then heats the air and the cycle is repeated.
- Hydronic Heat (Hot water or steam): In a hydronic system, a boiler heats water (to steam in a steam system), and the hot water circulates throughout the home through pipes. The boiler supplies hot water (or steam) to radiators located throughout the home. A separate pipe returns the cooled water back to the boiler. Usually a circulating pump is used to push the water throughout the piping system. There are three types of radiators available for hydronic heat systems:
- The vertical tube, cast iron type, is typically installed standing on the floor.
- Baseboard radiators can be cast iron or copper tube; the latter having thin metal "fins." They are typically located at floor level against the outside wall.
- Convector radiators also have finned tubing enclosed in a rectangular box, usually metal. Air circulates up through the floor level through the tubing and then flows out the top into the room. Some convector systems use a fan to force the heat out of the convector.
- Furnaces and boilers are available in gas, oil and electric. Generally, air conditioning systems (a/c) used with the furnace are electric, although, in some areas, gas a/c units are available. Package units in various combinations (gas heat/electric cool; electric heat/electric cool; gas heat/gas cool) are available but are used more typically for commercial applications.
A gas furnace utilizes a heat exchanger to transfer heat into the home. The gas flame mixes with air brought in for combustion inside the heat exchanger. The burned gases travel through the heat exchanger and out through the vent pipe and chimney to the exterior. At the same time, cooler air from the house is circulated by a fan around the outside of the heat exchanger. That air is heated by the heat exchanger, continues into the ductwork system and, eventually, into the home. Metal and/or masonry vents are used in lower efficiency furnaces due to the high temperatures involved.
Current manufacturers’ furnaces contain extensive electronic controls, so contacting a reputable, knowledgeable dealer for information and/or service is recommended.
Newer, higher efficiency furnaces may have multiple heat exchangers to allow the air circulating into the home to adsorb more of the heat from the heat exchange process. Multiple exchangers increase the efficiency and decrease the temperature of the burned gases being vented. As the amount of heat extracted from the burned gases is increased, moisture is created that can quickly destroy metal vents. With super high efficiency furnaces, temperatures are lowered and PVC vents must be used rather than metal. PVC vents will not melt at these lower temperatures and are resistant to moisture damage.
Gas furnaces should be certified by the Gas Appliance Manufacturers Association (GAMA) and boilers should have the I = B = R seal. These certifications and seals indicate that the Annual Fuel Utilization Efficiency (AFUE) and heating output capacity of your furnace or boiler have been determined and are accurately stated. Look for "Energyguide" information with any new furnace or boiler. This fact sheet is required by the federal government to be posted on every furnace model. This guide includes the Annual Fuel Utilization Efficiency (AFUE) showing a cost/use format that allows consumers to compare the operating costs of various units. Since 1992, new furnaces and boilers must have a minimum AFUE of at least 78%.
An Oil Furnace is similar to a gas furnace in that it has a fan/blower system to distribute the heat throughout the house. In an oil furnace, a power burner is used to mix oil with air. The mixture is sprayed or "fogged" out of a nozzle where the fuel is ignited by electrodes. Air is blown into the heat chamber, heated and then exits outdoors through a vent pipe and chimney. Like a gas furnace, an oil unit has safety devices to shut down the oil supply if there is a problem at the burner. A fuel pump is part of the burner used to pump the oil from a storage tank; this supply line is filtered so the oil stays clean.
An Electric Furnace contains resistance wire strips that are heated by electricity. A circulating fan blows cool air, returned from the home, over the heated strips. This heated air is then distributed in a ductwork system throughout the home similar to a gas furnace system. Since there are no burned gases involved, electric systems do not require vents or chimneys.
Electric Heat Pump
An Electric Heat Pump system is similar in appearance to an air conditioning system. An outdoor unit with a compressor and coil are used. Through a special piping system, the heat pump is able to use the compressor and coil to extract heat from the outdoors (even at sub-zero temperatures) and transfer that heat inside the home to a coil which is located with a blower. The heat is circulated into the house through a ductwork system similar to the one utilized with gas or electric systems.
A heat pump's heating performance can be compared using a Heating Seasonal Performance Factor (HSPF). All residential size heat pumps have this rating, and it is available from the contractor who installs the unit or the manufacturer. The higher the HSPF, the more efficient the unit. Since 1992, new systems are required to have an HSPF of 6.8.
Before purchasing a heat pump, check to see if its manufacturer is certified by the Air-Conditioning and Refrigeration Institute. This means that the pump has met strict standards for performance and reliability.
Automatic Controls That Save Money
All furnaces and boilers have controls to prevent them from overheating while the room thermostat provides heating in an even flow. Special thermostats are available which automatically raise or lower the room temperature at whatever times you choose.
Many people prefer to sleep at a lower temperature than their normal living temperature. The thermostat can automatically lower your desired temperature in the evening by any number of degrees you desire. In the morning, even before you rise, it can raise the temperature up to your desired comfort level. You can also have the thermostat lower the temperature during the day if you will be out of your home. Besides providing greater comfort, these thermostats can provide substantial savings in energy costs.
Hiring a Contractor
Choosing a contractor can be the most important aspect of heating system maintPenance, repair or replacement. Check the reputations of several firms with friends, neighbors and your Better Business Bureau (www.bbb.org/bureaus). Get estimates on the work to be done from two or three possible contractors.
Follow these guidelines before deciding to proceed:
- Getting An Estimate: Bids for extensive repair or replacement of heating systems should be submitted in writing. Estimates should always include a full description of the services to be provided. If the heating system is to be replaced, the estimate should include a full description of additional work required for the installation of ducts, registers, electric wiring, and any other work needed.
- Products and Services: Compare more than cost when examining the bids. Check the size of the equipment each contractor recommends. Ask each contractor to explain how the estimate of the required heating capacity and equipment was determined. Make sure the service and products of the contractor you use will provide the maximum benefit in both comfort and value.
- Warranties: Check the warranty offered: what does it cover, for how long and who will honor it? Always keep a copy for your records.
- Guarantees: The contractor you choose should provide at least one year of free service labor should any malfunction occur.
- Maintenance: Check the owner's manual and contractor’s recommendations regarding routine maintenance.
- The Final Contract: Read the final contract thoroughly and understand it clearly before signing. Be sure to keep a copy.
To learn more about home inspection, contact the following:
Your Local Better Business Bureau
Web site: lookup.bbb.org
Federal Trade Commission
at 877.FTC.HELP (877.382.4357),
Web site: www.ftc.gov
Air-Conditioning & Refrigeration Institute (ARI)
Web site: www.ari.org
American Gas Association (AGA)
Web site: www.aga.org
Gas Appliance Manufacturers Association
Web site: www.gamanet.org
U.S. Department Of Energy
Web site: www.doe.gov
* If you find any of the web sites listed above to be inactive, please contact the respective organization. Also, be aware that the above phone numbers may be subject to change without notice.