Inspected a home with a zoned HVAC system that had a thermostat at the downstairs and one at the upstairs to control the different zones. This is fairly common in my area. This was a one year old house. I typically operate the zones independently and then at the same time to see that they are functioning properly.

Usually the upstairs zone is independent of the downstairs zone, with each area being controlled by the thermostat in the zone. On this system however, with the upstairs thermostat in the off position, I operated the downstairs thermostat on heat mode and when I went upstairs I found that the game room area (which is open to the downstair area via balcony railing) and one upstairs bedroom were controlled by the downstairs thermostat. All other upstairs registers/ducts were not blowing because the upstairs thermostat was off.

On the majority of the newer homes I have inspected, the upstairs and downstairs zones have always been indepenent of each other. Other than the inconvenience issue of having to go downstairs to adjust temperature for two rooms of the upstairs area, could this also affect the balance of the system or have other potential issues?

Comments welcome.

Eric

Sounds kinda boneheaded to me. It's a stretch, but the only rationale I can come up with for doing that is that the owners requested that it be done that way so the gameroom and the one bedroom upstairs could be at the same temp as the lower level. The only way that I can conceive of where that would make sense was if the other upstairs rooms weren't planned to be used heavily (and the gameroom and bedroom were) and they wanted to avoid running the entire upstairs system.
That said, it's not likely to work well. Unless there's a separate return upstairs, it's always going to be warmer up there just due to simple physics: hot air rises; cold air sinks. Even with a separate return, it's a questionable approach, especially if there is any opening to the other areas upstairs.

Is there a chance that the physical design of the home precluded running ducts easily from the 2nd floor system to those areas, and the main floor system was used since ducts from there could be snaked into the area?

Kevin,

I was performing the inspection for the owners and they were not aware of the set-up until I found it. As far as the routing of the ducts goes, there was no reason the ducts needed to be on the downstairs zone. The HVAC equip. was in the attic and it appeared that there was plenty of room to configure the duct system and zones however they wanted.

The owners also complained of some rooms at various areas being colder/hotter than other areas. This complaint is pretty common on these one year old homes and often it seems to be related to direction the house faces, etc.; however, there have been times when the HVAC guys come out and do some tweaking to balance things out and it works.

Thanks for the reply,

Eric

I would recommend getting a tech to check it out. Believe it or not, it is pretty easy to get ducts crossed when you have been working in an attic for a few hours and sweat is dripping in your eyes; they all start looking the same.

Bottom line, the thermostat should be located to sample and control the zone it controls, anything short of that and the installer did not do it right.
I can't see the system in question, but it sounds a little screwy to me.

__________________
Jim Luttrall
Mr. Inspector.net, Inc.
Allen, Texas 75002

My thoughts exactly. The client also said that HVAC guys had been out before to adjust balance of system. I couldn't help but wonder if this was one of their "tweaks".

Seems like more and more I am wondering if the guys who actually have the licenses (Master HVAC, Electricians, Plumbers) are actually doing any of the installations or even inspecting/checking up on what what their trainees are doing.

I inspect a lot of new houses and I have to say, sometimes the sheer number and scope of errors and problems I find is overwhelming.

And yet, time after time my clients tell me that the builder has told them that a third party inspection is a waste of money.

Eric

Aah yup. Don't need not dang 3rd party 'spector in this here house ..

I did a new home final yesterday that the builder had told the buyer it was "done" ... "ready to move into". HAH ! Mind you this home is ~4000 s.f. and has a price tag of about $300K.

Cosmetic misses alone were an adventure. D/W not properly secured and out of line ... left side to right side over 1" in depth difference. Maybe the installer was still hung over and could see straight to line up the D/W. ?

75 gallon W/H pilot would not stay lit to heat the tank.

Garage door operator installed w/o infrared beams.

Electrical connections for controls of a gas furnace were not secured in the 'internal' J-box behind the access panel. The other furnace took an act of gyration as the A/C freon line was routed 'tight' against the access panel making it close to impossible to remove.

... and on it went. My client was very pleased and that is what counts.

__________________
Cheers - Nolan E. Kienitz, HCRI, PMP
Dallas Home Inspector
www.NolansInspections.com