Inspected a new construction home today, 2600 square feet and 2 stories. There was only one HVAC unit, one thermostat (upstairs) and one return register (upstairs). I thought it strange there wasn’t a zone control system for both floor levels, especially that there was only one return register upstairs (the bedrooms were located upstairs). Couldn’t find anything concerning this in the IRC, so I’ll just inform my clients. Any thoughts out there? Thanks.
Open staircase? Think old ‘gravity system’ for the return.
+1 on that. The upstairs may not need a return register at all. Cold air sinks.
I see that all the time here, in Florida. But here the return should be upstairs. (A/C runs most of year, heat rises)
I still think it is odd, myself, because it would seem to have better air circulation with another return. But I dont call it out, its pretty common around here.
Ooh, good point. My heating only climate bias slipped in…
My concern is that without a zone control system for the downstairs, the downstairs will always be colder no matter what time of year.
Yeah, that’s pretty normal.
But there’s no particular reason the downstairs will be colder. If the system is well balanced hot airflow to the downstairs can mix with the falling cold from upstairs, and all end up pretty even.
Right, Daniel…I was just going to ask where he lives.
Back in the day, I lived in a budget priced townhouse in Atlanta, with only a single unit serving two levels. The system had a damper in the attic ductwork labeled “Heat” and “A/C”. Once or twice a year I had to haul my fat butt up there to flip it. Something similar to this:
The sentence above reads as though there was only one return register and it was upstairs. Was that your intent? Were there return registers downstairs as well?
The position of the upstairs return is also helpful… floor… wall (high/low)… ceiling.
As mentioned above, Florida would typically be more concerned with removing the hot, moist air for better cooling.
For a truly balanced system, each room that has a supply should also have a return. If you are pumping cool air into a hot room and the door is closed or the windows aren’t sealed too good, with no return duct, the system will have a hard time cooling that room. Not very efficient at all.
In older homes, this obviously will not be the case. A common problem in flip houses is not trimming doors properly. I like to see a one inch gap between the bottom of the door and carpet. For this may be the only way to get any recirculation.
Sounds like a pretty standard installation here on Oregon. I just did a new 3-story house yesterday that was all on the same zone. Upstairs was probably 10-12 degrees hotter. Builders are just required to give you heat… they don’t seem to care about how much and where.
I would have to make note of that for my client. Not as a defect, but an FYI. They are going to be very disappointed once they move into that 3 story.
For a forced air system to operate efficiently, the volume of return air should equal supply. Leaving doors open, having adequate spacing under doors, and relying on staircases for air return are not signs of a modern, well built house.
And… what’s your point?
Don’t be an alarmist. As long as the kitchen has a granite counter top and stainless steel appliances the buyers are usually not concerned with mechanical systems.Sarcasm of course.
Welcome back to our forum, Kevin!..Enjoy participating.