Is Running Your HVAC Nonstop Good Or Bad?

Posted on: 4 March 2015

With the record cold snaps and heat waves the US has been experiencing lately, your HVAC system may be running nonstop these days. Or perhaps you have been advised to set your thermostat to "On" instead of "Auto," letting it operate continuously all year. Is that a good or a bad thing? Read on to learn why the answer to that question is: it depends.

Energy Efficiency

There are two factors that people typically consider when looking at energy efficiency: environmental impact and cost, and the two are interrelated. Whether your HVAC system uses more energy to constantly turn on and off or to run nonstop depends on the age and quality of the entire system, including your furnace, air conditioner, and ductwork.

You can ask a qualified HVAC contractor or repair person about your particular system. You could also try comparing two months with similar weather, using your HVAC continuously one month and on-demand the next. Your utility bills may give you the answer.

Continuous Furnace Use in the Winter

If you turn your thermostat to "On" in the winter, two things can happen. Your system will run continuously, with the furnace kicking in intermittently and the fan running the entire time. However if the system runs with your furnace blowing heat all the time, it could mean your home is poorly insulated and sealed. If the latter scenario happens during more than just a few sub-zero days, you need to look at your home's overall efficiency at retaining heat.

Running the furnace with the fan blowing all the time has one noted benefit: you are likely to feel warmer, even if the ambient temperature remains constant. Because running the fan keeps air moving and eliminates pockets of warm and cold air, you may be more comfortable (unless you're sitting right next to a vent).

Nonstop Air Conditioning

In the summertime, the biggest issue with having your fan run continuously is that your AC may not perform properly during very humid weather. Running the fan so much may keep the AC evaporation coil temperature too high, thereby reducing its ability to remove humidity from the air. If your home feels too muggy, change the thermostat to "Auto."

Air Quality

Some people like to run their HVAC fans continuously year round to improve the air quality. The more the air is moved, the fresher it is, even if it is being recirculated within the house.

If you run your fan nonstop, you need to make sure you are using the highest quality filter available for your model. Also, be prepared to replace the filter more often, which means inspecting it regularly to see if it has accumulated a lot of dust and debris.

HVAC Servicing

If you decide to run your HVAC system continuously (or it does it by default during extreme weather), you need to have your unit serviced more often too. You may want to switch from biannual checkups to quarterly. With all that use, you need your motor and other elements in tip-top shape.

Also, make sure your ductwork is clean and the vents are unobstructed. Keep the area around the furnace and AC unit un-littered and clutter-free, and don't forget to do a regular inspection of your chimney flue--that's part of the system too. Your heating and air conditioning service and repair professional, like Comfort Advisors Heating & Air Conditioning, can keep you on top of all these items, so you're ready for the next wacky weather spell.