Cooling home with air flow- what works? Settle argument please!

[Jenn]

We have 2 stories, and in fall and spring (and now with our late cool spring even in AL) we can cool the house down after dark by letting hot air out an upstairs window or pulling it out a fan we have going into the (vented with its own thermostat operated fan) attic. (With a window open to the outside downstairs- best for chimney effect- and maybe upstairs as well.) We are doing it tonight since the HVAC unit quit working and with 75F and dropping outside the 85F second floor will be better off with outside air. (Calling the HVAC folks in the morning- this is just our temporary fix for the night.)

Husband says leave only one window open, and has been turning on ceiling fan in the room with fan into attic running. I say as many windows open as possible all over house to increase inflow of cool air, and leave ceiling fan off since it just slows down flow of hot air out into attic with the turbulence. Any opinions? Don't worry, he's man enough to accept if he's wrong, and hopefully I'm woman enough to accept the same if I am.

So- ceiling fan on or off in room with fan exhausting room into attic? (with no people in it overnight)

To maximize cooling (or anyway get inside temp as quickly as possible down to outside temp) where and how many windows should we open? Is more better or worse? Upstairs or downstairs make a difference?

THanks for helping!

[gibbsgirl]

I'm not sure.

I have the house fan in the upstairs on. It definitely helps. No a/c running.

The ceiling fans help cause they blow on us and give us that comfort. I usually decide whether to run the fans on and how many windows or doors I leave open during night or day based on if it's raining and how much breeze will come in.

If the breeze is good I do more windows open. if it's raining or no breeze, I do the ceiling fans on or on higher.

Two of our Three bedrooms upstairs have ceiling fans. And, I notice a significant difference in the third. It's hard for me to keep it as cool in summer and as warm in winter there (poor daughter!)

So, if the breeze outside isn't cutting it, I say ceiling fans. If the breeze will cut it, and no rain, I say more windows.

[farmrbrown]

We've got the same basic set up as your house - temp. controlled attic fan exhausting out the eaves. The ceiling fan above the bed helps keep the air moving and bodies cool.
As many open windows as you can, sometimes there isn't a breeze when the air is heavy.
One thing I added was closable register vents in the bedroom ceiling to let the heat out into the attic quicker. Close them when it's winter or you use a/c.

[geo in mi]

First law of air flow is that air must go outside so air can come inside. I vote for having as many upstairs windows open as possible, and the fan in one of them exhausting air to outside. Here's another way to do it.




geo

[fishhead]

When I lived in AL we didn't have air conditioning but I slept fine with just a fan. Each night I'd close up all the windows except one in my bedroom and one in the living room. I'd put a box fan in the living room window facing out. That would put the noise of the fan in another room and it would pull in fresh air over my bed.

Before that I'd been living in AK so it wasn't like I was used to the heat but I still slept fine.

[NEfarmgirl]

We used to figure out which way the air was flowing through by opening a couple windows and seeing which one sucked the air out first. Then I would put a box fan in that window with it facing out and turn it on medium speed. After that I would open a few more windows on the opposite side of the house so the air was being sucked through.

If there are no people in the room then I don't see the point of running the ceiling fan. It is designed to cool people, not the room itself. If you have the attic fan running I would open the windows that would give the best flow through the house to the attic fan. For 4 years we managed to cool a 1500 square foot house with a small window swamp cooler designed for 1 room by running it on one end of the house and putting a box fan in a window opposite side of the house. We did run ceiling fans in the rooms that we were in because it did help having air movement, put they were turned off when the room was empty.

[gila_dog]

I think that the more windows you open the better. The idea is to replace the hot air inside the house with cool night time air from outside. Ceiling fans running will stir up the air, keeping hot air in a room from settling near the ceiling and staying there. But I think the main thing is to open the windows at night and then close them during the day to keep the heat out and the cool in.

[StL.Ed]

I was always told that if there is a breeze, to open the upwind windows on the lower floor, and the downwind windows on the upper floor for maximum flow; however, if there is no breeze, open all the windows for a "chimney" effect.

Fans complicate the matter, depending on the whole layout of the house. An upstairs attic fan might not draw air through the downstairs, if upstairs windows are open; but, if you sleep upstairs, having upstairs windows open will cool that area better.

You could both be right, depending on the objective.

[Harry Chickpea]

Ceiling fan OFF unless it is literally blowing air on you or creating enough draft to encourage your being cooled by evaporation. If your fan uses 50 watts, ALL of that 50 watts eventually goes into HEATING the air in the room. Even moving air increases the heat in it, since heat IS molecular movement. (You can prove the effect by measuring the temperature of a couple cups of cool water, putting it in a blender, and letting it "blend" for ten minutes. The water will be warmer simply from being moved around.

The question you didn't ask is as important as the one you did. Air in the southeast has significant humidity. If you turn your AC off at night and use outside air that is only marginally cooler that the air inside, you may be increasing the humidity level inside to where the AC actually has to work harder than if you had never opened a window. It may seem counter-intuitive, but in the southeast, the primary function of AC is often to simply remove the humidity - and it takes a LOT of energy to phase change water from the gaseous state to a liquid.

[gibbsgirl]

forgot to say...our windows open both top and bottom. you just slide whichever one you want.

I try to remember to open the bottom half downstairs and the top half upstairs. I want to upper air in the downstairs to drift upstairs, and the upper air in the upstairs to drift outside.

[Jenn]

Thanks all! Geo in mi that house actually HAS a chimney! Just with windows. Harry we guessed the humidity issue (though not the wind direction aspect) through experience. So now temp difference has to outweigh humidity difference to open windows. Will have to pay more attention to windspeed.

Sadly our windows don't open at the top. We also have a sharp turn from stairs into 2nd floor so I think the window at top of stairwell should have warm downstairs air exiting it, but it usually seems to be admitting cool air! And maybe most of 2nd floor outside air comes in from other 2nd floor windows as well. We have threads/ yarn on windows we use most and still haven't sorted out which windows do what- maybe because it is often different. But in am we shut windows either when temp outside is getting close to inside or when the yarn is hanging straighter showing less air flow.

[NEfarmgirl]

I sometimes will put a box fan at the top of the steps to pull the air up and that seems to help quite a bit when the main floor is a lot cooler than the upper floor of the house. We have a turn in our steps, but the fan does manage to pull the air up through the stairwell. We generally have a south breeze this time of year so it is easy to figure out which window need opened, but sometimes from the east or north and that does change things.

[Michael W. Smith]

I guess it would all depend on if the fan in your attic is strong enough to suck the air from downstairs. (Are you opening the door to the attic and can feel a draft coming through the door and up into the attic or not?) And if there is a draft, does the draft decrease if you close all the 2nd story windows and just have the first story windows open?

I would think the more windows you have open, the more cooler air is coming in. (Our windows open either from the top or the bottom, so many times we slide the bottom one UP and the top window DOWN - so as (at least in my mind) cool air comes in through the lower window and the warmer air goes OUT through the top.

And while I appreciate and admire the "old ways" - working with hand tools rather than power tools - and think it would be neat to live back in that time - I can't even imagine life before electricity and trying to sleep in a stifling hot room! (I prefer a cooler bedroom, and while we haven't turned on the bedroom window AC yet - when it gets too warm, it's on and set in the mid 60's.)

And to make matters worse (before electricity), many people only bathed once a week. I can't imagine the poor farmer's wife who had to sleep (or try to sleep) beside her husband in a stifling room who had worked out in the field ALL day - sweating ALL day . . . . . . and the day before . . . . . and the day before. Of course, the wife might not smell too pleasant either, working up a sweat during the day from physical work as well as cooking a meal over a hot fire (or stove).

You have to wonder, did many people back then, simply sleep outside where it was cooler than in the house?

[gibbsgirl]

Originally Posted by Michael W. Smith

You have to wonder, did many people back then, simply sleep outside where it was cooler than in the house?

Michael, google "sleeping porches". Here's one link. I think they're very cool and have considered setting one up on one of our porches eventually.

Here's one link

http://www.bobvila.com/articles/slee.../#.VVJ7jM90zIU


As far as the bathing goes, I think people did do cleaning up but not a full bath. Perhaps a good scrub down with a rag.

Interestingly, I can tell you that my daughter and I quit using shampoo and conditioner and sometimes also soap in the shower about a month ago. We've seen some amazing changes in our hair, skin, etc. One of the unexpected changes was that our body odor does not actually smell the same anymore and it doesn't smell nearly as bad.

We think it has to do with the same idea that shampoo and conditioner is a vicious cycle that makes your hair go from extreme dry to extreme oily because it's trying to overcompensate.

Our skin has improved and our nails are stronger. Used to have acne problems and weak nails. We suspect the same chemicals in the shampoo and conditioner were causing acne irritation and weakening our nails.

Used to have to use lotion and chapstick constantly. It was painful we were so dry. Haven't used lotion since then, and chapstick use has cut way back.

The body odor issues we think may have been worse to manage before because it all seems to be related. The chemicals in the soaps/shampoos/conditioners were more irritating and throwing our bodies chemistries off.

Who knew, right?

Anyway, I kind of wonder if some peoples body odors or amount of body odors may have been different back then because they didn't use so much of this stuff in those days either.

Heck, I've read old advertisements that were touting that consumers should start using shampoo once a week. So, it wasn't always around and it wasn't always daily.

Wish I could have asked my grandmother more about this. She always had her weekly hair appts. It had never occurred to me that those appts might be the only time she washed her hair!

Okay, sorry I drifted and kinda hijacked your thread Jenn.

[Maura]

If you have a basement, bring the air through the basement. Open one window, the one farthest from the door, and open the door. Use a box fan on the first floor to force the basement air toward the stairs, although if you set it up right you’d only need the attic fan.

[Patchouli]

With an attic fan you definitely want as many windows open as possible.

[TexasRed]

I know what I'm about to throw out there is not the same as your situation, but it works in our home for air exchange. If I'm way out in left field, it's okay to tell me so

We are in the high desert, so use evaporative coolers not AC. Basically a big fan that blows across wet pads. Even without the wet pad component (we often just run the "vent" setting at night and cool days. The concept is the same as your airflow delima; hot air out - cool air in. A box fan in a window could be used the same way an evap. cooler is.

Some of them are window units, most are mounted on the roof. Some are run through duct work like a heating system, but I've had several that just had a downdraft straight into the house. Sometimes on second floor, sometimes on first - it doesn't matter.

Anyway, on to the guts of the way it works. Turn in the box fan (any window) to draw in the cool air. The rooms you want cooled, we open a window just enough to make a Kleenex lightly cling to the screen. (this vaires with distance from fan and house size). You do this in every room you want to cool. The "light cling" is the air movement (or exchange) making that happen. Open the window too far and the movement stops, tissue falls to the floor. Open it too little and it is almost sucked through the screen, too strong.

To achieve that "perfect cling" will ensure an adeuate air exchange in the house. It has been tested down to a science here, and works quite well - night or day. Once you have figured out the right amount to open whichever windows, it becomes a kind of default setting.

I would like to know if this woud work in these farmhouse settings? Maybe it is just not enough air volume without the cooler fan? Or the cooler fan could be substituted with the attic fan.

Hope this helps someone achieve a cool nights rest.

[NEfarmgirl]

Originally Posted by Michael W. Smith

And to make matters worse (before electricity), many people only bathed once a week. I can't imagine the poor farmer's wife who had to sleep (or try to sleep) beside her husband in a stifling room who had worked out in the field ALL day - sweating ALL day . . . . . . and the day before . . . . . and the day before. Of course, the wife might not smell too pleasant either, working up a sweat during the day from physical work as well as cooking a meal over a hot fire (or stove).

You have to wonder, did many people back then, simply sleep outside where it was cooler than in the house?

My grandparents washed up every evening, but only bathed on Saturday evening because they had church Sunday morning. I spent a lot of time with them as a child and they didn't stink. Grandpa smelled sweaty until he cleaned up, but he farmed. Grandma washed her hair and had it styled once a week. I still can't understand how she kept her hair nice the whole week, because mine is a mess after sleeping on it one night. If it was too hot, the kids would sleep on the enclosed screened porch where there was airflow.

I do know others that slept on the screened in porch when the temps were to warm inside.

[Forcast]

my parents and grandparents would put this big full size window fan in the kitchen window, blowing out. Then at night would open only the bedroom window on second floor. The cool air would be sucked through the bedroom window out through the house by the kitchen window. But no other windows are open.

[haypoint]

I live in an area that is nearby one of the worlds largest bodies of fresh water and it stays cold year around. As a result of this lake, night time temperatures drop into the 60s most summer nights. Daytime temperatures are often in the upper 70s to mid 90s. It is common practice to open windows in the evening and shut the house up at day break, holding the cool air in and keeping the hot daytime air out. With the house closed up, hotter air rises and the upper floor will be warmer. I know many people that do not have any sort of air conditioning and stay comfortable.
Many things operate on the hot air rises principle. Hot water, too. The heating radiators in my house are much smaller in the second floor than the main floor. Heat from the main floor flows up to the second floor. The radiator's water is not pumped, but flows upward as it is heated, as cooler water sinks to the furnace.
So, yes, open a window on the first floor and a couple on the upper floor and let the heat out. A breeze from a ceiling fan feels nice, but it isn't taking the heat out of the room.