BTU stands for British Thermal Unit, which is a measurement of how much heat it takes to raise the temperature of a pound of water by one degree (F). Without getting too technical, it’s basically a unit of measure we use for heat. How does that tie into your HVAC system? Well, your air conditioner doesn’t really have a BTU. (It’s measured in tons.) We mainly use BTUs to measure your furnace.
We do a heat load calculation on someone’s home to determine how many BTUs are necessary to heat the space. First, we take into account the number of doors and windows in the home, which are probably the biggest contributors to heat loss. We also look at insulation, the amount of wall space, and square footage of the room or home. All of these variables are used to determine how many BTUs are necessary to heat the space to a desired set point.
You might hear someone ask, “How many BTUs does this furnace have?” It’s pretty much based upon the heat load calculations of the space to ensure the furnace is big enough to keep that specific space comfortable. We know that we need to raise the temperature by a certain number of degrees based upon the design temperature and where you might be in the country (how cold of an area it is). That’s how we size the furnace for someone’s home.
Sometimes an HVAC company will just guess the BTU using general rules of thumb. This is pretty dangerous; you’re basically going to come away somewhat dissatisfied with the results. If a proper measurement isn’t taken into consideration, the sizing of the unit isn’t going to be suitable, ultimately leading to discomfort in that particular space. If the unit is undersized, it’s going to run much longer than necessary and won’t last as long. If the unit is oversized, it will start and stop too frequently, which can also be hard on it.
If a homeowner is interested in getting a quote for a new HVAC system, or if our technician was at someone’s home and they set up a visit from our comfort advisor, one of the first things that we would do is take a look at the actual space that requires heating. We’ll do heat load calculations very early in the process so that we can size and match the right equipment to the space. That then leads us to determining the cost of the new system.
If you’re in the market for a new HVAC system before the next year’s cold season arrives, maybe you’ll want to get ahead of the situation and reach out to us now. Contact us online or give us a call at 540-483-9382.