Grrrrr. For the past week I've been struggling with achieving a comfort zone of even temps in my house. Yesterday was THE WORST day. I have 3 heat pumps and I'm trying to keep them from doing battle with each other. I had all the thermostats set at the same temps, however, when the heat pump for the main area of the house (lr, dr, kitchen) turns to the heat cycle (temp set at 68) the heat rises (the lr has a 22 ft cathedral ceiling open to the staircase bridge/gallery that crosses to the upstairs bedrooms). Consequently the upstairs overheats. When that occurs the a/c upstairs comes on and the two units are at war -- one is heating and the other is cooling. It becomes unsufferably hot upstairs and the only way I can seem to alleviate the sitch is to turn on the gas fireplace downstairs.
The master bedroom wing is to the right off the main living area, has 3 rooms and operates fine until the cold air from the upstairs a/c infiltrates and it goes to the heat cycle.

I cannot seem to figure out how to set these things to maintain an even comfortable temp throughout. At the present time I have the upstairs set to heat at 64 and cool at 69 -- otherwise the heat is stifling. Downstairs I have the heat set at 67 (which is a tad chilly). I have all the overhead fans running to circulate the air. I also have the overhead fan in the main house (downstairs) running.

I'd welcome suggestions.

Edit: Below is a sketch of the house layout. The second story is the bottom sketch and the rec room in the second story sits over the garage. I think if you double click it'll be easier to view.

 

Have you tried the overhead fans in the other direction? HPH

 

Val,
an HVAC guy should be able to put in a low voltage cut out relay on the second floor unit.
Basically the control wire to turn on second floor cooling would be disabled by the control that enables heat on the first floor.

Specifically. The 2nd floor AC request line would run through a relay that is normally closed, i.e makes contact and is connected to the compressor.
When the first floor Heat request line is turned on it will pop open the relay and break the connection.

A more elaborate ( read $$$) approach would be to get an integrated controller.
Something that would look at outside temperature and figure out "the smart thing" to do with both controls.

 

Yes I reversed the settings when the outdoor temps started cooling down.

boltonblue I'm afraid its going to come to that. Apparently they didn't teach hvac when my +1 went to engineering school. His approach has been, "hmmm I'm not sure what we can do about this," or, "its cold in here, have you been fooling with the controls?" or, "its stuffy in here." or he shuts off the fans when he gets uncomfortably cool and forgets to turn them back on when he leaves the room. Yet I'll keep him.

 

Val,
With the caveat that I haven't seen the technical data on your system or the installation...
The relay approach should be fairly cheap.
The actual relay is $10-15, throw in the base wire etc. you might be up to a $100. for materials. (Probably pessimistically high)
A good tech should be able to wire it all in, in less than an hour @$100/hr (pessimistic again)

So you should be able to get out of it <$250, maybe a lot less.
Just make sure the tech clearly documents what he does so you don't go crazy later trying to fix the second floor AC.

if you can wait, we can come down for a visit and do a site inspection.

 

How long would I have to wait. Its hot in here.

 

I don't have any expertise in the HVAC area. But, I will offer this advice:

Back in the 90's some friends of ours had an HVAC failure in July when here in the Washington DC area we had a record heat wave of days in the 90's and 100*F temps for most of the month. They called, and called and virtually everyone they called said that they were servicing their "contract" customers first and it was over three weeks before they could get anyone to come and fix their system.

I am not a fan of extended warranties or service plans but based on their experience that is the one Full Maintenance Agreement that we now carry. As neither of us do well in the heat. If need be we have a high tech wood stove that can heat our whole house in the winter. But, we need to be cool in the summer.

When we did have a problem (turned out to be blown fuses) they were here within hours.

 

We have an HVAC expert here now. He discovered we had a melted relay in the upstairs unit and is now doing a check to be sure it will work properly and our issues should be resolved. YAY.

 

Sounds like an easy fix.

 

I had a similar situation this year when we replaced our main AC. The house built in 65 when AC was not an everyday service, therefore they had not built the ductwork to maintain air velocity through the system (no reduction in the duct size). This made cooling our bedroom, which is at the end of the run, really hot. We wound up running a separate supply and return to the bedroom, and that resolved our problem.

Maybe an openable skylight (I was thinking outside the box).