Hondo123

I have a cape cod built in '67 with central air and aluminum forced air ducting. It appears the previous homeowner added some insulation to the roof. However in the summer, the second floor continues to get warm and stuffy even with all the registers wide open, while our basement is morgue cold. Our intake ducting near the fan unit in the basement does have a small louvered vent that I assume is there to draw in cold air into the system when it is blowing, but this hasn't made much of a difference to cooling the house to the best of my knowledge.

I'm very curious if there's a "better way" to move all that good cool air that has sunk into my basement to the top floor where it can be put to good use. I have often wondered if perhaps there was some sort of solar air movement system I could use to draw that cold air to second floor, or perhaps some addiitional ducting that could be installed in tandem with a standard electric recirc fan. I'm not wild about having a fan running all the time, which I why I wondered about the solar unit, which could run continuously during the day "off the grid".

Anyway, very interested in potential solutions to this challenge, even if they do not incorporate some of my initial ideas.

joechuckg

Do you only have one thermostat either upstairs or down. If so you might want to look into a zoning system where a thermostat would be added so you would have both floors controlled by dampers in the ducts. Can be kinda expensive but it would solve your problem

Hondo123

A second themostat will do nothing more than cause the A/C to run continuously as it tries to cool the top floor. The cooling is not a problem. The problem is I have a large pool of over-cool air sitting in my basement (probably "ponding" from the rest of the house) and a hot second floor (or call it third if you count the basement as a floor). Just need to get all that good cool air moved to where it's needed. A dual zone system would probably just make the basement even colder than it is already.

Any other ideas? Am I the only homeowner with this kind of problem?

Daddytron

Cold air will always have a tendency to settle as the warm air pushes its way up... duct booster fans are a simple (but noisy) solution. If you have means of installing a door on the basement at the top of the stairs and keep it closed, this would be an energy efficient solution. unfortunately... all the windows on the main floor and upstairs allow all that free heat from the sun into the house, and keeping the blinds closed makes a house feel like a dungeon. In my house, i keep a fan running at the base of the stairs, to push the cold air around, but once it hits around 80 outside, my AC runs non-stop and can't keep up. If you find a solution, please let us know

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Hondo123

A good thought, however we do have a door at the top of the stairs, and we do keep it closed nearly all the time. Didn't know about duct booster fans, but might consider it. We have Energy Star rated windows where the sum comes in on the two large ground floor bay windows, so sunlight heat is not so big an issue on the main and upper floor (which has only one window facing the sun throughout the day). In fact, most of the upper floor roof is shaded by a large maple tree in our front yard.

You would think "they" could come up with a system that would provide even distribution of heating or cooling throughout the entire living space. It's a no-brainer that heat rises, and cool air falls. I wonder why home systems are not designed to maximize distritrubtion throughout the "thermal container" in a multi-floor home. This just seems to be good design philosophy, opposed to just installing some ducting and a heating/cooling source.

I may ultimately need to come up with my own solution, perhaps additional ducting that chimney's straight up through the center of the house bypassing the middle floor with some sort of reversible fan attached to a thermostat that will move somewhat large volumes of air from basement to top floor, and reverse in the winter.

Anyone else with thoughts on this? I know my problem can not be unique.

Daddytron

We just had our once-a-year heat wave... temperatures in the high 80's to low 100's. and for the first week of this, my a/c was running constantly, trying to get the house to 74. During the second week of it (average daytime high of 91 with a 85% humidity). I flipped the switch on my thermostat to run the furnace fan constantly, the a/c would actually have a break for about 15 minutes every 10 minutes of running, and I was able to get my house down to 70. The basement is probably only about 5 degrees cooler than the main floor now. Maybe this will work for you?

__________________
Over budget and behind schedule...
That's how I roll :)

CallMeVilla

You need to have the AC system checked for leaks. This sounds like a problem of insufficient cold air distribution to the top floor and a major leak in or near the basement. An air flow meter can quickly identify the rates on various floors. Bad joints, improper returns, holes cut by prior owners . . . all can be the problem.

Good luck living in the basement to stay cool.

EdB868

How many square feet and how many supply registers are on the upper floor?

It's possible there are not enough supply air registers.

Veteran HVAC professional
www.needtoknowit.org/HVAC

CallMeVilla

Stay on him EdB . . . He needs your help!

EdB868

If you live in the northern band of the country,
chances are the duct system was designed for heating.

Cooling requires more air flow than heating -
I suspect there is not enough air going to the upper rooms.

You should have two supply registers in each of the
upstairs rooms.

One possible solution (not that easy, but possible) is
to run a 9" duct through a 1st floor closet to an area
behind the 2nd floor knee wall, then install a 9" x 6"
tee and run 6" duct to each room.

Also, make sure the ducts in the basement are sealed
with duct mastic.

You will most likely have to turn down the damper
during the winter, otherwise it will get too warm.

If that is not practical, look into ductless split system.

37 year HVAC professional
www.needtoknowit.org/HVAC