Vacaville is an easy town to spot: it’s about halfway between Sacramento and San Francisco, with a brightly colored playground for kids at the Nut Tree Plaza. I know plenty of people in Northern California, like Vacaville folks, who live in a small, quiet community, then commute into one of those bigger cities during the work week. Their favorite thing about living outside a metropolis is how much quieter it is. In fact, did you know Vacaville is home to a special retreat spot where people go to enjoy silence? It’s called Silent Stay, but I don’t know if I’m supposed to be talking about it—at least not loudly, anyway.
It’d be a shame for all that quiet to be lost when you get inside your own home, but I get calls all the time about noisy appliances disrupting a family’s peace, especially furnaces around this time of year. If your furnace seems to be getting louder each winter, it could be because of its proximity to the return vent, a lack of duct lining, or it may just be all around too darn big. So for suburban homeowners in search of relaxation, I have three ways to get your furnace running quieter than a terrible singer mouthing Christmas carols at the annual neighborhood holiday party this winter.
No. 1 – Move the Furnace Away from the Return Vent
Your furnace is always going to make noise because in order to create heat it uses combustion, and that’s never quiet. This noise finds its way into your home through the ductwork and out the vents. As sound waves travel most efficiently in a direct path or a straight line, every time they have to make a turn, a major portion of their energy is lost. So, the more turns you can incorporate into the journey between your furnace and an opening in your HVAC system, like a return vent, the less sound will be emitted into your home along with the hot air.
A problem I see somewhat frequently is that furnaces are built with the return ducts located directly above or below them. Return vents suck air from a room back into your HVAC system to be warmed, and they’re typically larger than other vents. If they are located right above a furnace, noise is coming straight out of it and into your home without a single turn. Furnaces with return vents set off to the side are a lot less likely to disrupt the peace and quiet in a home.
If a homeowner has space, I almost always suggest having a furnace positioned so that the return vent is offset, and there are at least three 90 degree turns in the ductwork before any of the air is released. The most drastic way to reduce the noise coming from your furnace is to move it away from the return duct, or any other duct with an opening, altogether. Updating ductwork or vents can be tricky business, so I highly recommend you hire a professional if you’re considering adding new ductwork to your HVAC system.
No. 2 – Insulate Your Furnace’s Ductwork
It’s possible for the ductwork in your HVAC system to be insulated, which does more than just prevent air leaks—it also cuts down on noise. If your HVAC system doesn’t have any insulation, then the hot air being blown out of the furnace is running along bare metal, meaning that noise is likely to echo against the metal ducts and be carried out into your home.
One of the key places in an HVAC system to make sure there is internal insulation is in the space between the return grill and the furnace blower, because, as I mentioned above, from the furnace to the return duct is where air leaving the HVAC is released most directly, and so it’s the noisiest, sort of like how I-80 West is the most crowded as you’re first heading out of Sacramento, but your commute gets quieter as you exit off into your own sleepy town.
Internal HVAC insulation, also called duct liners, is different than normal insulation because it only comes in one type—fiberglass. Like many of the other parts of your HVAC system, including ducts, filters, and the heat pump, HVAC insulation will wear down and quickly deteriorate if not properly installed, cared for, and maintained by a trained professional. This is particularly worrisome because the air coming out of your furnace will begin to blow not only sound, but fiberglass and other debris into your home, where the toxic particles can create minor health issues for you and your family. To guard against all of this it’s best to hire a trained professional to install this insulation, not only for the sake of your ears, but for your health.
No. 3 – Downsize Your Furnace
An oversized furnace means more than an extra large heating bill from Pacific Gas & Electric—it also means that your HVAC system is creating an airflow too great for the rest of your system to handle, including the return vent and the ducts. I’ve already told you about how important it is to find the perfectly sized furnace for your home, but I didn’t really go into the noise issue. With more air, you’re also going to have more noise coming from inside your furnace and out into the open where it’s sure to bother you and the peace and quiet you were looking for when you moved into your home’s suburb. Having a trained HVAC professional out to determine and install the right sized furnace for your house will quiet down the entire system—and your home.
It’s getting cold in Northern California, and chances are you’re wanting to stay in a bit more, keep warm by blasting your heat, and enjoy a quiet evening. But you can’t keep warm and relax in silence if your furnace is sending too many soundwaves through your ducts and vents. Call on a local professional to evaluate the position of your furnace, its size, and the insulation in your ducts. That way, you’ll enjoy as much heat, and as little noise, as possible. Just imagine the relaxation that would come with that.