Tell Me Why This Is a Bad Idea: Home Cooling edition

My house has an unfinished stone basement which, even in the hottest part of the summer, will stay around 70°. Some days, like today, when there's a weird spike up to 80°+ but the average temp is fairly low, the basement will be a full 20° cooler than the house. (Granted the house stays fairly cool on days like today - one of the advantages of a brick house.) And there are plenty of days when it's almost warm enough to justify firing up the AC, but not quite. And it's still nice and cool in the basement.

So, I'm trying to figure out something that will push all that cool air from the basement up into the rest of the house. I'm thinking of getting my hands on a salvaged HVAC fan and jury rigging something to tie it into the existing ductwork so that it's only pulling cool air from the basement, not recirculating air from the returns like it does now.

Obviously, this is going to be clunky, and I'll need to be able to reverse any hackwork I do in order for the HVAC to run efficiently. But this will be a temporary, seasonal setup.

So, tell me why this is a bad idea.

This is a bad idea for 2 reasons: 1-Radon, a radioactive gas that seeps out of the ground, your location may or may not have this. 2-Humidity, basements are humid and musty generally, the extra humidity would increase the wet bulb temperature possibly yielding a net loss for comfort.

On the other hand you could set up a pumped ground loop and a water to air heat exchanger in the existing ducting system (with proper drainage for condensation) Have a backhoe and a few hundred feet of PEX?

This doesn't really work the one time I saw my parents try it. You get a blast of cool air and then nothing, stone isnt a very good conductor of heat. Good way to warm the basement up though.

I think they just left the filter access door off(ancient 50s oil furnace).

alex wrote: And it's still nice and cool in the basement.

in the early 1970's my friend's house had no air - they had a kitchen table and would eat all their meals in the unfinished basement - then head over and work on cool projects in their workshop area. this was an early man cave.

an attic/whole house fan sounds like what you are looking for.

Install in ceiling of top most floor and vent through attic

In reply to Grtechguy: Doesn't help during the day, it will help to suck cool air into the house at night, then close up the house to keep it cool(ish) until about mid day when it will heat up again.

I would love an attic fan, but alas, we have no attic.

slopecarver wrote: In reply to Grtechguy: Doesn't help during the day, it will help to suck cool air into the house at night, then close up the house to keep it cool(ish) until about mid day when it will heat up again.

My neighbor uses theirs all the time during the hot summer days,

it pushes hot air out of the attic and pulls cool air from the basement.

Alex, you don't need a true "attic". Your house has trusses and at least a ridge vent?

I've always been curious about this too, but everyone says it doesn't work...

I grew up in central GA without air conditioning ( late 70s/mid 80s.) We had an attic fan, and ceiling fans in every room. We'd open all the windows at night and pull in the cool air, then close up the house until around mid day.

And then we'd spend the rest of the day laying miserably in a pool of sweat unable to move for fear of heatstroke until about 2 am when it finally cooled off enough to berkeleying sleep.

But in the mornings it was awesome.

i did that in my house- i'd open the walk out door in the unfinished basement to let cool air in, with the door left at an angle to force the air to circulate around the basement, and put a fan in a window in the living room or my bedroom upstairs blowing air out the window...i'd close every other window and door except for the one with the fan in the window to help keep the air moving where i wanted it, and the house would stay relatively comfortable all day long and only get unbearable towards the end of the day on the hottest and muggiest of the days.. it helped that it was a relatively small house (660 finished square feet upstairs) and was mostly shaded by some big trees to keep the direct sunlight off the house for most of the day..

i didn't use a very big fan, either... just a little $10 18" multi speed fan from Wal Mart was enough to keep things cool as long as i didn't let the house get too heat soaked..

Grtechguy wrote: Alex, you don't need a true "attic". Your house has trusses and at least a ridge vent?

Well it's a brick house with a flat roof. I'm sure there's some air space up there, but I honestly don't know if there's a ridge vent. This place was built in the 1880's.

What I'd really like to do it replace the skylight over the stairwell with an attic fan during the summer time. The light is nice, but sucking the hot air that accumulates up there would sure be nicer.

Does the skylight have a UV cover? That alone would likely substantially reduce the temperature.

An additional cover, you mean, or is the material itself UV resistant? No in the first case, I dunno in the latter (but the it's only a couple years old, so I'm guessing it's up to modern standards). During the stupid hot part of the year this year, I'll probably put a tarp over it.

We get temperature data and power usage data broken down into monthly averages from our power company, and each summer, without fail has been hotter than the last. July and August of last year had average temperature of 89°. And our HVAC is just barely adequate for our house and it's starting to wuss out, so any little thing I can do will help.

One caveat about attic fans - the ones with thermostatic switches can be a problem. My friend's house had one. A small fire started and the attic warmed up from that... whole-house fan kicked on, and WOOP - not a small fire any more.

I grew up in central GA without air conditioning ( late 70s/mid 80s.)

Damn dude. You're my hero. I'd either be dead or in jail for murder. Can't stand being hot.

I jus put a real big box fan at the base of the stairs and point it up, it makes a very big difference in the temp upstairs. Of course where I live 15% humidity is about the most we ever get, so any moisture that is brought up basically acts as a swamp cooler.

icaneat50eggs wrote: I jus put a real big box fan at the base of the stairs and point it up, it makes a very big difference in the temp upstairs. Of course where I live 15% humidity is about the most we ever get, so any moisture that is brought up basically acts as a swamp cooler.

in that case you should look into evaporative cooling.

icaneat50eggs wrote: I jus put a real big box fan at the base of the stairs and point it up, it makes a very big difference in the temp upstairs. Of course where I live 15% humidity is about the most we ever get, so any moisture that is brought up basically acts as a swamp cooler.

My mom does that too, both basement and to the upstairs. It does help, though I'm not sure how much.

I'll be the dissenting vote. Your idea can work, but under certain situations. We really can't say it will or won't without knowing a lot more about your house. Some of the cautions previously posted are valid. Do a search for passive solar design. These houses are designed to cool in much the same way as you are describing.

All the houses I grew up in only had evap coolers, it worked pretty well here in the dry part of Texas. I never knew what humidity was till I went to college near Houston and lived in an unairconditioned dorm.

poopshovel wrote:

I grew up in central GA without air conditioning ( late 70s/mid 80s.)

Damn dude. You're my hero. I'd either be dead or in jail for murder. Can't stand being hot.

I grew up in central SC same way till I was ~8 y/o. We lived in an 1800's farmhouse with no A/C, no insulation and one of those huge floor register heaters. That one burned down, the new house my dad built with the insurance money had central A/C. Talk about a HUGE relief. The m/h we lived in till the new house was finished had these noisy ass window units.

The schools had no central A/C until probably the late '70's, we had to leave the classroom windows open and dayumn it still got HOT.

One of my dad's favorite stories: he lived in Savannah, GA in the early 50's. Nobody had A/C, not even the rich folks, in the summertime you opened the windows at night and sweated like a hooker in church.

Dad came into a little extra cash, convinced his landlord to let him put an attic fan in the duplex he was living in. Got it all done, nice job, timer on the wall, you name it.

First night he and his first wife turn the thing on and jump in the sack, start some poke and tickle. Next thing ya know they are both slapping themselves all over and running for the bathroom, seems the attic fan was sucking the sand gnats through the window screens.

I vote buried water loop also, there is not enough cool in the basement to last all day.

A few things I do is leave window plastic up all year round except for a couple of windows that get fans. I turn fans on at night blow cool air in then. Two fans blowing in at the lowest points of the house and one out at the highest point. Turn the fans off early in the morning so they don't suck in hot, then close the windows. It helps to close curtains in the day time to reduce greenhouse effect too.

One thing I have always wanted to do is find a way to vent the refrigerator condenser outside in warm months and just let it heat the house in cooler months.

I have a basement and a log home with a tin roof. I just put a fan at the bottom of the stairs tilted back at a 45 degree angle. Usually cools the upstairs about 10 degrees. It's a lifesaver when you don't want to run the air.

I built a swamp cooler for my shop out of a 5 gallon buck a shammy towel and a shop fan... Works like a charm (when humidity is low)