Circulating basement-cooled air - Should I?

[MS]

I am wondering if it's advisable to circulate the cool basement air throughout the house, using the blower and ducting from the forced air heater?

I would need to install an auxiliary air intake into the return duct (small house - only one return), in its basement run and cover up the original inlet on the first floor. I would also need to figure out how to control the blower. I don't see any of this as a big technological problem, the question is: is it worth it?

My biggest concern is the potential for some musty smells traveling from the basement (the usual basement smell) throughout the house.

Aside from this, it seems to make sense - take the very cool and comfortable temp air, even on very hot days, from the basement and distribute it throughout the house, where each level (two floors + basement) go up in temperature by what seems like 5-10 degrees.

The house does not have central air, nor a whole house fan. I know the benefits of the latter - let's not discuss that again - but am interested in your thoughts of circulating the basement-cooled air.

[*CBHVAC*]

Least of your worries... Basements, being typically more humid and dark, are breeding grounds for molds you wont see....till they find a food source..:)

You can do what you want. This has been talked about many times. Your basement will not act like a heat sink, in enough of a manner to make a difference for more than about an hour, then, the basement temps will be the same as your home....warm.

Geothermal systems, (basically what you are wanting to do) that use nothing but buiried pipe to remove heat from the air, can have several hundred feet of pipe buried deeper than your basement, and still require an evap and compressor to remove, or control humidity. Your basement does not have the capacity.

[SQLit]

Do you have duct work in the basement? If so open the dampers and turn the fan to ON. If you do not have dampers then your going to have to provide a return for the air. Pretty big one like leave the basement door open. Low pressure air does not find its way easily through small openings. It will work to a point. The mustiness will probably go away because of the dryer air and the fact your moving air all of the time. As long as the basement is the same size or larger you will get some benefit. When I use my whole house ventilator I usually get outside temp +5-8 degrees.

[MS]

So, in effect the underground pipe can only replace the condenser? Sounds like a small benefit...

Mold - yes, thank you for reminding me - and I take your point. Makes sense not to introduce it to other levels of the house.

I didn't realize the cooling capacity of the basement "operates" on such a limited efficiency (one hour or so?).

Basement Humidity - I do have that condition, but a dehumidifier is in place and collects about 45 pints in 24 hrs. I am converting it, today, actually, to discharge the condensate into a sink so it will always be in the loop (it won't shut off when its tank fills up).

I guess the only hope I had was that the dehumidifier (or two) would be capable of removing enough moisture from the basement to dry the air sufficiently. One DH can now maintain 55% to 65% humidity level.

The grand plan was to install two dehumidifiers that would both drain into a sink. With two of them running, my supposition was that enough moisture could be removed to handle both, the natural basement humidity, as well as the additional humidity introduced by the air intake from the rest of the house (it's a small cape-style home, 26' x

30,' two living levels + basement).

Assuming the dehumidifiers can reduce the humidity well enough and fast enough, we are still back to the natural cooling capacity of the basement itself; only one hour? that's a disappointing realization/fact(?).

I look at it like this: an extra dehumidifier is only about $150. With most of the rest of the hardware (ducting and fan) already in place and the basement acting as the cooling apparatus, this sounds like it could work - in theory.

I am not being argumentative - I respect the laws of physics - just trying to see if something can be done within the "gray areas" on the margins...

[Joseph Meehan]

It really depends on a number of factors. However it should reduce the humidity in the basement, and that should reduce any mold production.

Note: MOST mold is not harmful. However that kind that is is very harmful.

[Kevin]

[m Ransley]

My underground 25x25 basement never gets above 72 even with a dehumidifier and 90+ outside , I cut in returns as you are thinking about. I have central air and it helps balance and circulate air a bit. A sawsall, jigsaw a closeable vent and 15 minutes are all it takes. If you need a new dehumidifier a 70 pt Sears is quiet and operates to

45f. I just bought one. The cooling benefit depends on your basement , location, ground temp, size of windows , type, amount underground and air infiltration. For the effort and cost it is a good experiment.

[MAG]

Why not just apply the $150 to a window-rattler AC for the upstairs? That way you would be directly cooling your living space with a machine designed to do just that?

Best of luck to you with whatever you decide. Let us know how it works out.

Marc

[MS]

Did you block the return intake on the first floor or did you add new ones in the basement and let them contribute only in the summertime?

[m Ransley]

I actualy added one on the second floor inlarged one of 2 on the first and added 2 in the basement. I open and close them whenever.

[m Ransley]

I dont block the first floor, for AC you need movement

[William Brown]

[bill]

no