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FURNACE:
Heating System Basics
The majority of American homes are heated with a forced-air furnace, most commonly fueled by natural gas, but also by electricity, liquid propane or fuel oil.
How a Furnace Works
A furnace works by drawing air inside a heat exchanger, where it is warmed with a flame of natural gas, propane or fuel oil, or with heated electric coils. A blower sends the warmed air through the house via metal ducts; it enters the room through a register or grill in the floor or wall. Indoor air is circulated continuously through the system, so a furnace filter is used to contain dust, pollen and other airborne particles. An older home might have a boiler, fueled by natural gas, liquid propane or fuel oil. A boiler works by heating water and circulating is through pipes to radiators, where it warms the surrounding air. Unlike a furnace, a boiler doesn't circulate air throughout the house, which is why the air in a boiler-heated home might seem "stuffier."
Radiant Heating
Radiant heating is making a comeback in many new homes. Instead of circulating heat by moving the air in the room, a radiant system heats objects - including people. The most common form is radiant floor heating, which uses electric cables or small tubes of hot water embedded in a concrete floor or under a tiled floor. During the height of its popularity during the '40s and 50s, radiant heating was also installed in wall or ceiling panels. Homeowners in the Midwest usually use radiant heating as a supplement to a primary heating system. It's most often installed under the floor in uncarpeted areas such as kitchens, bathrooms, laundry rooms and garages. For added luxury, radiant heating cables can be embedded in a driveway - no more shoveling!
MAINTAINING YOUR FURNACE
When was the last time you changed or cleaned your furnace filter? Failing to replace or clean the filter regularly can be costly! Dust and dirt can work their way into the blower and coil assemblies, reducing the furnace's operating efficiency and eventually causing damage to the motor. Heating professionals say simple dust and dirt are the cause of almost half of their service calls; most manufacturers recommend changing or cleaning filters at least every other month (once a month is best).
Get an Annual Service Checkup
In the Fall for your Furnace...In the Spring for your Air Conditioning
An annual service checkup by a heating/cooling professional is usually a good idea. The technician will check the flues and temperature settings, examine the heat exchanger for cracks, and check the safety mechanisms on natural gas units. A $69-$89 annual tune-up per system can reduce your heating unit's operating cost by three to four percent.
What to Expect
During your annual fall check, your technician should:
Clean and adjust the burner, pilot and ignition assembly
Check the heat exchanger for cracks
Check the pilot thermocouple
Examine all filters
Check vent piping
Test gas piping for leaks
Test the electronic ignition
Test the fan
Adjust the burner for efficiency
Test the limit switch
Measure the manifold gas pressure
Adjust thermostat calibration
Check belt/tension
Test safety controls
Examine the draft diverter and lubricate the fan motor
During your annual spring check, your technician should:
Check refrigerant
Examine all filters
Clean condenser coils
Clean condensate drains
Check blower motor operations
Test safety controls
Advise on condition/cleaning of evaporator coil
Keep in mind, that just like your car, your heating system needs regular care and maintenance. And just like having a good mechanic for your car, you should have a good technician for your heating system.
REPLACING YOUR FURNACE
Although older forced-air had efficiencies in the range of 56% to 70%, modern heating systems can achieve efficiencies as high as 98%, converting nearly all the fuel to useful heat for the home.
Conservation efforts and a new high-efficiency heating system can often cut your fuel bills and your furnace's pollution output in half. Upgrading your furnace from 56% to 90% efficiency in an average cold-climate house will save 1.5 tons of carbon dioxide emissions each year if you heat with gas.
If your furnace is old, worn out, inefficient, or significantly oversized, the simplest solution is to replace it with a modern high-efficiency model. Before buying your new furnace, first make every effort to improve the energy efficiency of your home, then have a heating contractor run a heat-loss calculation to size your new furnace. Energy-efficiency improvements will save money on the furnace, because your home will need a smaller furnace. A properly sized furnace will also operate most efficiently.
Efficiency Rating
If you live in a cold climate, it usually makes sense to invest in the highest-efficiency system available. In milder climates with lower annual heating costs, the extra investment required to go from 80% to 90%-95% efficiency may be hard to justify. When shopping for high-efficiency furnaces, look for dependability, and look for the ENERGY STAR® label. Buy a system with a good warranty and a reputable company to back it up. Your All Season's Heating and Cooling sales representative can help you make the right decision.
When buying gas systems, specify sealed combustion. Sealed-combustion furnaces bring outside air directly into the burner and exhaust flue gases (combustion products) directly to the outside, without the need for a draft hood or damper. They generally burn more efficiently and pose no risk of introducing dangerous combustion gases into your house. In furnaces that are not sealed-combustion units, back-drafting of combustion gases can be a big problem.
Beware of Carbon Monoxide
If you have a natural gas furnace, or any type of fuel-burning appliance, regular professional maintenance can literally save your life.
A properly functioning gas appliance produces harmless water vapor and carbon dioxide, which are vented out of the house. But if a heat exchanger is cracked, a flue pipe is plugged or if the pilot light doesn't have an adequate amount of oxygen, the natural gas won't combust properly, causing deadly carbon monoxide (CO) to develop.
Symptoms of Carbon Monoxide Poisoning
When this colorless, odorless, tasteless gas is inhaled, it enters the bloodstream and robs blood cells of oxygen. The symptoms of carbon monoxide poisoning mimic the flu -nausea, headaches, dizziness, fatigue - and long-term exposure can be fatal.
One way to check the "health" of a natural gas appliance is to look at the color of the pilot light. The flame should be at least 80 percent blue. If the flame is mostly yellow, it could beproducing carbon monoxide - have the unit checked by a professional immediately. But remember that CO can be produced even if the pilot light is blue, so invest in an annual professional tune-up and follow the other preventive measures listed here.
To protect your family, invest in a high-quality carbon monoxide detector. Similar to a smoke detector, these electronic alarms alert you to dangerous levels of CO. Carbon monoxide is lighter than air and rises to the upper levels of your home, so install the detector close to bedrooms and living areas.
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