4 Common (and Dangerous) Habits That Ruin Your HVAC System

Given how tempting it could be to forget about out HVAC systems after turning it on, it can be easy to forget about what they need. The cost of some of our bad habits can be instantly seen in our energy bills. But there are certain habits everyone should avoid at all costs.

1. Closing vents in unused rooms

To many penny-pinching homeowners, closing the vents of unused rooms seems like a common sense way of reducing the energy bill. And they’d be right – if we’re talking about anything but modern homes equipped with central air conditioning and heating.

The problem with this practice in modern homes is that people doing this assume that closing the vent means less energy cost, since the system would theoretically be covering a smaller space. The problem is that HVAC systems are designed to control the temperature of the entire residence, not specific rooms. Inside doors are rarely ever sealed like doors that lead outside, meaning that it’s impossible to leave one room cool and another hot. Since closing a vent forces other vents to work harder reach these sealed rooms, it puts more air pressure on your entire system. If many vents are closed, you can even cause the system to malfunction, since they require airflow to control the temperature.

If warm air can’t enter the system, the coil will freeze and prevent any more cold air from being generated. Alternatively, it could overheat the system and cause the thermal limit switch to cut the furnace to prevent a fire. Either of these outcomes can be fatal on your HVAC system depending on their severity.

2. Leaving windows and doors open while the system is in use

Those with a green thumb will often opt to open their doors and windows instead of turning on their air conditioning. Some of us would rather turn on the AC a few degrees if we deem it the better option. However, there is a minority who either has a misguided desire for both worlds or is just very confused about how air conditioners work; one of the worst things anyone can do to their HVAC system is use it while leaving a door or window open. Just ask a hotel owner or grocer − they know just how expensive it can be to keep their places invitingly cool despite how frequently the doors swing open.

Leaving a leak in your airflow as big as a window can bring enough warm air to keep an air conditioner constantly working, and inevitably freezing. Letting the winter air come in through the front door can put enough strain on your furnace to either cause it to switch off or fail catastrophically. Remember to switch off your thermostat if you intend on leaving a window or door open for any extended period of time.

3. Ignoring the air filter

Keeping tabs on your air filter is one of the easiest things you can do to make sure you have a healthy system. Ignoring it and letting it collect a carpet of dust creates a blockage that forces your air conditioner to work harder to push out air. It also spreads dust and other allergens throughout your house, which is completely opposite to what the filter was designed to do. Remember to replace or clean your frame every thirty to ninety days (depending on the needs of your home). Taking care of your filter will save you more than what you spent on maintaining it and will keep your air clean to boot.

4. Not replacing old equipment

There is no mistaking it – HVAC systems can be pricey. But frugality should never be a reason in keeping old and run-down equipment. Some obvious signs to watch out for to see if something in your system needs replacing are:

• You’re having to call maintenance more and more frequently.

• The energy bills are inexplicably rising.

• Your home has humidity issues (typically, dry winters and humid summers). Watch out for excessive condensation, since this might indicate a problem.

• Dust is everywhere.

• Your system makes excessive noise while operating.

• You’ve had the same equipment for more than a decade (heat pumps and air conditioners, 10 years. Furnaces and boilers, 15 years.)

Even if you follow good practices and have regular preventive maintenance performed, all HVAC equipment needs replacement at some point. Consider seeking a professional’s opinion if you think your home might be overdue for a fresh system. Remember that HVAC is an investment, and leaving your home to go without maintenance because of frugality or laziness is never an option.

Jason Wall is an HVAC technician with more than 23 years of experience who enjoys baseball and spending time with his family. He writes tips for Griffith Energy Services.