I have no clue what we have but there is a "switch" in the basement that DH flips twice a year that sends more air upstairs in the summer and more on the main floor in winter. We also installed attic fans years ago, as well as ceiling fans in all the bedrooms, which we seldom need to use.

bpath, Ours is higher efficiency too, but still, I would seriously try running the fan. Our older furnace had a fan as well but we didn't know what it was for and he said the variable speed together with the fan is what we needed for the size house we have. We never hear it. We've actually stood in front of vents a couple of times to make sure it was on. It was! I guess it pulls the hot air down to the cool air below and the cool air to the hot air above and the A/C only goes on when it needs to. Our upstairs has been consistently 1-2 degrees cooler than the downstairs for the month it's been installed.

Joanie, I really don't know much about it either and maybe that's what we're supposed to do too and no one told us. I think I'll have to look into that!

When we installed a variable speed Trane heatpump, the foreman told us to run the fan 24/7. Well we did and the house was SOOO humid! Needless to say, we don't do that anymore.

We have a two stage or variable system -- not a heat pump, just typical Ac/furnace. We got it to run the low speed to dry the air for allergy reasons, but it did improve the eveness of temperature in the house. I also love the fact that you don't hear it kicking on.

Hmmm....we've had exceptional humidity outside lately but the not in the house, though I admit, we do run it a bit on the chilly side. :c). I like that too lascatx, we really can't tell it's on!. I'm just so excited that it worked just how he said it would...so often it doesn't and then your stuck.

So I went Googling to see why our indoor humidity increases with the fan on the "on" position. It echos exactly what we were told years ago. Maybe this is specific to heat humps and/or living in a humid area (we do)

Explanation with Graphs

A simple solution is an inline booster fan. My daughter has 4 bedrooms upstairs. Without a booster fan the area would be intolerable during summer heat.

Adding an attic exhaust fan, the kind that goes through the roof, made a world of difference in my house. I could not believe how much cooler the upstairs became when that is running. I also close the downstairs ducts in the hot weather and use ceiling fans in the bedrooms. What an improvement! Glad you found a solution, too.

We have a heat pump and live in the Midwest where it is very humid. We have a split floor plan which makes the house three stories. Our master is also over the garage, and our house inspector told us his house was a similar layout and to keep the thermostat on circulate. Even through 110 degree heat and humidity so high you start to sweat within seconds of stepping outside it has been cool in our bedroom. We keep the thermostat at 78.

I agree that it is so nice when something works as expected. I am so happy with this AC company and this installation was our first experience with them. But we recently had an issue late one night. We ran all the checks we could and then called to leave a message in hope of getting an appointment the next day. The owner answered from home and told us his phone had been going crazy. There had been a power surge in the area that overheated compressors (we hadn't noticed anything but he lives in the area and works this area). Told us what would probably resolve it (and did) and said to call if we had any further problems and they would work us in (not needed). We slept cool and no charge. I wish I had someone like him to call in every trade.

lascatx, wow, now that is a really savy business owner because you will forever be his customer AND you'll probably also refer people every chance you get. I love reading stories with out comes like that!! I recently had a lovely experience with a new insurance broker, I didn't have to do any research, got really good coverage, saved 1600 in annual premiums AND the agent was low key and fabulous to work with. I've already sent some folks her way.

Monicakm, that's a pretty interesting article, I even went back to her original article where some of the replies had some interesting arguements too. I think it's sort of a hit and miss depending on the house and system being used. Even though it feels like a hot summer day in the deep south outside, it's not humid inside. I bookmarked the article though for future reference (just in case) Thx!