A furnace is super simple. It draws air in from the living space, it heats it up and delivers it back out to warm the home. Modern furnaces are all forced air systems, and there are three configurations.
- Up-flow furnaces are placed in homes with basements.
- Horizontal flow furnaces are designed for homes with crawl spaces.
- Down-flow furnaces are for homes built on concrete slabs.
If you have an older home, you may even have a furnace that uses physics to distribute the air instead of employing a blower. That is, the cooled air sinks down into return vents and the heated air rises up into the living space through the ducts. Hot air rises, cold air sinks. It’s an incredibly efficient way to circulate air, but it doesn’t quite have the impact and
immediate gratification of blower units.
However, that little physics lesson can help us understand why up-flow furnaces tend to have longer life spans than the others. When air in your home reaches its desired temperature and the thermostat shuts down the unit, the hot air in an up-flow model will dissipate its stored air quickly because it will rise out of the unit on its own. With the other models, heat collects and doesn’t allow the unit to cool down as fast, thus they incur more wear.
That’s something to think about if you’re building a new home. Another thing to consider is the heat source.
Gas furnaces are very common and use either natural gas or propane. With either fuel, the furnace works the same way. Gas enters into a chamber, is ignited by a pilot source and warms the air within a heat exchange chamber. The air is blown into the living space through heating ductwork and the exhaust gases are vented out of the home. The only difference is that natural gas is usually delivered via a municipal connection and propane generally comes from an on-site tank.
Electric furnaces use heating elements, or strips, to warm the air instead of a fossil fuel source. Everything else works the same way.
As with all HVAC systems, air filtration is critical to effective heating. Make sure you change filters often and have your furnace professionally serviced on a regular basis. To find out if a furnace is right for your home, contact your local ARS air conditioning and heating installation specialist today.
