Adding Rooms to Existing Duct System
28 Jan 2026 · 1 min
Derek Cole discusses adding a sunroom or room addition to an existing HVAC system. The speakers cover thermostat placement, improper duct tap-ins, and sizing issues that affect comfort throughout the whole house.
Chapters
They've had the sunroom. And, yeah, I just want to tap in a few little runs to my duct system. Throw it over here. Miserable. No, not going to happen. Not going to be comfortable. Because now you're building three walls of glass. And this lady in particular was. It was on the southwest side of her house, and she was like, I'm using my unit. I said, where's your thermostat at? She pointed to the middle of the house where it's supposed to be. There is no way that thermostat can read what's happening in that sunroom.
And what you need to be aware of. Most people say, well, if it doesn't work, this addition, I'm fine with. If I'm not comfortable, you're not just going to be not comfortable in that room. It's going to affect the whole house. Because when you take that air off of that duct system to go into that room, you're taking it from somewhere that needs it in the rest of the house. So you're not just going to be affected in that new area. You're going to start surfing in your old part.
Yeah, it's going to. I mean, it fixed the whole envelope. What we call the house is the envelope. So it. I mean, there's a cause and effect. It's like taking medication. I mean, yeah, you're curing one thing or you're masking over symptoms, but you could have higher blood pressure or could lead to liver problems. You know, there's always a cause and effect. So when you start tapping into existing things and not sizing it properly, you're gonna have challenges.
Problems, not challenges. Problems.
Yeah, you're not gonna be comfortable. I mean, you're spending that money to add the room on, and you've turned a comfortable home until the whole house is now uncomfortable. Exactly.
Yeah.
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