Derek Cole answers listener questions about HVAC sizing and efficiency. He explains why a load analysis and measuring your house is required to size replacement units correctly, and why longer run times actually improve efficiency and dehumidification.
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Hey, on this episode we talk about why do you have to measure my house to give me a price? And why is my unit constantly running in the heat? You ask your comfort and energy questions and they get answered. This is the Ask Derrick Cole Show. Hey, this is Derek Cole. Welcome to episode 85 of the Ask Derrick Cole Show. Answering your home and energy questions. Why do you need to measure my house to replace my unit? That's a good question because probably you've never heard that before. Okay. The reason we need to measure home is to do a load analysis on your home. Now, 99.9% of the time when we replace your unit, it's going to be the exact same size. Yes, that is true, but in this state you have to do a SCALDA load analysis, which measure the home, measure the windows, measure doors, measure insulation, see what direction the front door is facing, south, north, east, west, whatever that's going to affect the load. That's going to determine, after you do all those calculations, what size unit you need. Now, like I said, 99.9% of the time it's going to be probably the same size. Now, this year already, I know of two situations in which we've gone down half a ton in size because they had a 40, 30 year old unit and they added a deck to the home. They enclosed a deck to the home and what was the south side is now the north side because all the windows are being shaded by the deck they added to it. They've upgraded the windows from single pane to double pane. So things do change in the course of a home life cycle. So you do that measuring and the loaded analysis to make sure that size equipment is still good for the home. Like I said, I know at least two of them so far have gone down half a ton in size because they've made those improvements to the homes in the last 20, 30, 40 years from what it was when it was first installed. So measuring the home is something that's kind of rare in these parts apparently because not too many companies are individuals do them. But it's something you have to do for your license in this state because if something were to go wrong and you would need to pull that load analysis, you would have to show the state inspector, yes, the load came up to three tons. We installed three ton. You know what went wrong, then we can figure it out, but we can show proof. Yes, we did our diligence, we pulled a load on that house and we did it. My unit keeps the home cool, but doesn't Stop running. You don't want to stop running. I mean, think about when it's 98, 100 degrees outside. Think about getting in your car and then driving to the store. How many times did you turn off the ac? Probably not ever. Your home's the same way. It's trying to keep that same temperature all throughout the day. So it's not going to stop running if it's on a set point it's trying to reach. Now if it reaches that set point, then obviously it's going to turn off. But the unit running for a long period of time is not necessarily a bad thing if the unit is sized. To go back to the first question. If it's sized properly, it is running, it is better for it to run longer because it's more efficient than turning on, turning off, turning on, turning off. It's kind of like a related to miles per gallon in the car. Okay, what's better for your car? Is it better to hop on 95 and drive to Wilmington or is it better to go through up 401, stop and go traffic all the way down to Wilmington, which is better? Gas mileage, the interstate. Why? Because it's running, not stopping. Same way for your unit at home. So the more runs, as long as it's keeping you comfortable, it's fine, it's cool. Think about it again. You get in your car. Well, let's say we take that trip to Wilmington. Okay? So you get in your car from Laurenberg, you go into Wilmington, it's a two hour drive. You get it on the interstate, it's 98 degrees outside, you got the air on full blast. You get to about maxing about, you know, 10 minutes into the trip, you start to turn down a little bit because you're getting comfortable. And guess what you start noticing it gets really cold the slower the fan goes. So then you turn the temperature up just a little bit because now you're cold in the car for the long trip. Same way in your house. The longer the unit runs, the slower the fan speed, the better it is to dehumidify and cool your home. The more time that air has to sit over that cooling coil and actually extract the moisture and the heat out of it before it blows it back in. The better it is for you. Same way. Same reason you get cold in the car on that two hour trip. You know, you're nice and toasty to start with and then you're getting cold as you go on and you turn the temperature up a little bit or turn the fan down same way in your home. So it's not really a bad thing for it to keep running all the time. And plus, with the 9,800 degrees, you don't want it to stop running. If the unit stops running, you have a problem. Did you see that? All right, that's episode 85 of the Ask Derek Cole Show. Be sure to hashtag your questions. Ask Derrick Cole, and we will get them on the show.
