497. The Dangers of Dust Buildup in Your HVAC System
28 Jan 2026 · 11 min
Single-speaker podcast advising homeowners about how dust and dirt degrade indoor air quality and HVAC performance, increase energy use, and accelerate system wear. Explains basic heat-transfer mechanics (indoor/outdoor coils, frost/defrost on heat pumps), lists common contaminants (pollen, spores, pet dander, lint, dirt), and gives practical maintenance guidance: check filters monthly, replace filters at least every three months, consider appropriate MERV ratings, watch for airflow/duct bypass, and get professional HVAC service twice a year.
Questions this episode answers
Check the air filter every month.
Three months (three months is the max).
Twice a year.
90% of the time.
Two to five times worse (EPA cited).
Chapters
As a homeowner, if you're a homeowner, you understand the most important thing is keep your home comfortable and safe. And a big part of that is your indoor air quality, your heating and air system. After all, the heating air is one of the biggest users of energy, of the appliances you have at home, of the appliances in your home, the heating and air is one of the biggest energy users. And one thing that contributes to the energy uses and your indoor air quality is dust. Dust can affect your air quality in your home, but it can also cause wear and tear on your system because it's going to act as an insulator and make things work harder. Heating and air is all about heat transfer. So to get into the mechanics of it, you have, you know, the indoor coal or the outdoor coil, things you, things you actually see as dirt, debris, grass clippings, maybe even on the outer coal, as this stuff gets on the coil and makes it harder to transfer heat. Heating and air is all about heat transfer. You either bring in heat into the house or you're taking heat out of the house. So in air conditioning mode, you're taking heat out of the house. It works the same as your refrigerator. Everybody, you know, has that in home, and everybody has a heat pump. It's your refrigerator. So it's taking the heat out out of what you put in there. If you put a bottle of water in there that's warm, it's removing the heat. Therefore, the bottle of water seems cold or cool, depending on when you get it. So heating air is the same way in your house. It's trying to remove the heat. Or when it's in heating season, you have heat pump, it's bringing heat into the house. It's taking heat from the atmosphere, taking heat as much as you can. That's why you see frost on the outdoor coal during heating season. And then when it goes in defrost cycle, it burns that or melts that frost off so it can keep operating normal. So you want to make it as easy as possible for that system to get the heat transfer going on. Where there's heating or cooling season, you want to make it as easy as possible. Well, dust and dirt do not make it easy. Dust and dirt buildup matters. It could be different particles. It could be pollen, it could be spores, it could be pet dander, lint, dirt. It could be a number of things, but they're also not good for your system or, and sorry, and not good for heating air. So, you know, dust buildup is going to start straining that system. It's going to make everything work harder. It's going to cause a buildup in that coil. It could be a build up on that motor blower, motor blower wheel. It could build up and make everything work harder. Yes, you're still getting heating or air in the house. Air is still moving, Air is still, you're still comfortable with the temperature, but everything is starting to strain and starting to work harder. And their energy bills are going up. Your energy use is going up. We talked before about energy, you know, energy bills skyrocketing. Well, again, you want to, if we're talking back then, you want to control what you can control and what you can, you can't control energy prices, you can't control the cost of electricity, but you can't control how much of that you use, how much electricity you use. You can control the dust and dirt build up on your system, making your system run efficiently as possible. And hey, a great secondary benefit to getting rid of the dust and the dirt is better indoor air quality. We spend 90% of our time indoors today. 90%. And the EPA says indoor air is two to five times worse than outside air. We've talked about that before. We talk about the, the trappings and the VOCs and wouldn't even talk about dust and pollen and spores and pet detner and everything else is that's in the environment, in the air. So you just start by changing your filter every single month. You should check or change your filter. Why I say or is because some months in the middle of the year, in the, in the middle of the season, the system is not running a whole lot and that filter might need to be changed, but it does need to be checked. So check and change your air filter every month. How do I know I have the right air filter? Well, that's a whole different question for a professional. If you're not sure and that professional H Vac person is at your house, you need to ask that question. If it has not been brought up, you need to talk about your filter, your habits. The first line basically of defense for you, the homeowner, things you can control, things you can do is changing that filter and keeping that filter clean, checked and changed every month, no more than three months, regardless, regardless of the season, if it's dirty or not. If it's been there for three months, it needs to be changed. Three months is the max. You want the air filter to stay in your home. You want to get that changed out. If your filter is not getting dirty, but your system is getting dirty, Then your air, then the air is bypassing that filter, is going past the filter to get to the unit. So you could have a number of things going on. With duct system, with airflow, all, all these things could be going on. But getting back to dust, dust and dirt. Dirt is the number one killer of heating and air conditioning systems. So keep the dust and the dirt out, get it. Main gear system maintained twice a year, serviced by a professional. And they know what they're doing, they have a checklist, they go through it with you as well as to what looks good, what doesn't look good, what needs to be improved, what can be improved. Now, if you want to make those improvements again, it's totally up to you, but it should be the company, H Vac company's job to let you know what's available and what could help you. Now, you can say no, say yes, you can. It's your home. Do what you want to do. But as a homeowner myself and as a father, I would always want all the options on the table. If I go to a doctor and, you know, my son's sick and I would, I would want the options available versus the doctor assuming what I would want done. Doctor assuming what I want done does not give me peace of mind to let me make a choice. Now, I can ask that doctor or that professional what their opinion is and then I can make a determination or decision on my own. But you always want to have the opposition presented to you to see what you want to handle. If you want to handle anything. But to get started, to get the dust out, make sure you check the filter, make sure you change that filter. But checking it every single month, having the right filter in your home, the filter that's going to help out, help out your system and do the best job for you. It's like going to the doctor. Everybody is different. Every home is different. There's not a one size fits all mentality, especially when it comes to air filter. And the higher the MERV rating, the more efficient the filter. Is it getting the smaller verticals? The challenge usually is the fact that the particles you're trying to stop are the ones you can't see. Once that dust is laying down there on the desk or on the floor, that dust is heavy enough to be, to be there. It's not airborne, it's not going through the air filter anymore. It's heavy enough to be sitting there, but you want to attack it and get it before it gets to that point. You're seeing a whole. You're seeing a bunch of dust pile up to see what you're seeing. A bunch of that's happening for you to see it. But you want to control that before it gets to that point, before it gets to a pile that you can see. You want to filter it out, get it out of the air, get it out of the system, and that would do. Do the best for you.
More from Derek


713. Fan "On" or "Auto"? The Thermostat Setting That Could Be Making Your Home More Humid


712. Why Is My Upstairs Always Hotter Than Downstairs? The Truth Every Homeowner Should Know