keeping house cool

24 is cold, 30 is acceptable

we all are definitely different

24 us just starting to get comfy, 30 is way too hot. i set the ac's at 27, with compressors on. if compressor kicks off, depending, i'll turn the temp down and fan down to keep compressor on. the humidity is a killer for me. understanding, it is jacking my cost up, but for myself, well worth it.

if house is already built or a rental, then a bit more difficult to cool. old house i completely redesigned, to make the difference, as that was mine, and planned on living there for long time. the original plan, wasn't working at all. so a lot more overhang, and double walls on expansion, and insulation, all helped. now, here, the rental. fairly well made, 1st floor self cooling in cool season, get little sun, except for kitchen, which is almost seperate, and stays at ambient temp or 5 degrees higher. the 2 spare bedrooms, upstairs, are basically storage now, and master gets the later sun upstairs, so not too bad, but hot, and ac is necessary. also ac necessary on 1st floor, sun exposure or not, in hot season. cool season, the 1st floor is like entering ac on a hot day. actually quite chilly some days.

if building, you can really prepare and make a huge difference in exposure with your design. i never lived in tropics, but seem to be learning very quick. didn't realize how brutal the sun could be. also, keep the buddhism out of the house building, can't face this way, head in bedroom has to go this way............sorry, ain't happening. next house will be ugly, but practical, and very little ac will be necessary, even in hot season, except for sleeping. 3 sides will be double wall, very few windos, the 4th will be all glass. roof or rooftop sitting area, completely shaded by another roof. for sleeping, i'm still, cool the room off enough for lite sheet, even if meaning have to turn ac on, so i don't sweat with it. impractical, but hey.

electric went out last week, gave it an hour or so, ok, call ruysuk, i need ac, no arguements, as they are also ac corrupted. as long as electric is under 3000 and i'm comfortable, i can deal with that. haven't broke 2000 yet, maybe this month for 1st time, in just over a year. will be rearranging inside of house, so bedroom will be sleeping only, as it is the tv room also, which means many times, both floors are ac'd, which is a waste, once tv brought downstairs, it will be one ac on at a time, majority of the time. hopefully. my brother's electric bill, in philly summer heat, over 300 usd/10000 baht a month, so if feel good.

The value of attic insulation is still uncertain, BRIAN1874 vs. Khun Paul. In logic, I agree with Brian, but Paul presents evidence to the contrary. Anyway, in my new house, I am planning to do away with the attic altogether, for now.

Walls are the problem; keeping them from becoming a high capacity, low discharge thermal capacitor of the kind you would want in a solar heated house in colder climates is the challenge. Compared to an all masonry house, walls with insulation between the studs would, I think, lower the heat storage.

I did not know that using a fan and airconditioner at the same time is a no-no. The bedroom in my house is narrow and long (3.0mX6.6m) with two hot walls and a low capacity airconditioner (smallest LG, 8,500 BTU, I think) on the long wall at one end. For proper airconditioning, the room should have two of them along the long wall. But with the bed placed at one end of the room in front of the airconditoner, I get by with one. I keep it at 24C and run a pedestal fan aimed on me in the same direction as the airconditioner. I do use a light comforter all year, the kind you can buy in a plastic case in stores like a Tesco or a big C. Now, you have got me worried about using the fan.

OK, I should I lose the comforter for a light cover, and try to go a bit native as Paul suggests.

L A , a practical house does not have to be ugly !!!!!! before you even think about the house , think about the plot , which way does it face , can i put a house on it where the majority of the windows will face north or east , certainly the main room ones anyway . will i be able to establish a shady outside seating area . ect , ect . get the land right and youve won half the battle . people are differant , and as such their , tolerances to heat vary greatly . work out how cool you want the inside temperatures of the house , and remember that its only april and october that a realy hot . then use the materials that are readily available to work to that temperature . yes you can get any house cold enough , but as soon as you go into the heat , you will melt . keep it comfortable , without going over the top . otherwise your body will never adapt to the climate . im not being largist , or whatever the correct P C term is , but do big people not feel the heat more than lesser people ?

simple deduction watson it called insulation and the term is R. factor the higher the number the more
protection you have for both heat & cold the most important area to insulate is the ceiling you want
at least R20 R 30 is what is recommended so let your wallet decide how much protection you can afford

The question of using attic insulation depends on where the heat is. Heat always flows from hotter to less hot. If your attic is hotter than your room you will benefit from ceiling insulation. If you have a well designed attic space with foil under the roof and lots of ventilation your attic should be about the same temperature as the outside air. If you open your windows and never use the AC your rooms will be as hot as outside so with a good attic you don't need insulation. But if you have the standard hot Thai attic it will help even if you don't use an AC. In two rental houses with hot attics I put in fiberglass insulation in the rooms we used most. On a sunny day even without the AC on if you walked between rooms it was easy to tell which room had ceiling insulation.

In the house I built I have ceiling insulation and a good attic where the attic temperature stays about the same as the outside air even on a bright sunny day. And I built double block walls with 2" of fiberglass in between for an R value of between 9 and 10. We've found it effective to open the windows at night after it's cooled down and close them in the morning as it warms up. During the day there's only about a 2 or 3° temperature rise inside the house. Without the ceiling insulation it would be higher. And, of course, when we do use the ACs they'd have to run longer.

I've found that using a fan with the wall mounted ACs here gives me a more comfortable room. When I built our house I tried to locate the ACs as centrally in the room as possible to give a uniform temperature. But when the AC cycles on I don't like a stream of 20° air blowing directly on me when I'm lying in bed, watching TV, etc. So the ACs are mounted off center and I use fans to mix the air to get back to a uniform temperature. This has worked well at keeping the room comfortable and keeps the ACs from cycling erratically.

As Khun Paul and Saint say, acclimating yourself to the environment is also a major factor is staying comfortable. Getting used to the heat means that when we do turn on the ACs they're set to 28°. Which my friends back in the states gasp at but that's very comfortable for us. It also keeps me from feeling as hot when I go outside.

im not being largist , or whatever the correct P C term is , but do big people not feel the heat more than lesser people

hey...........what are you trying to say us larger frame, more body mass, especially if good portion muscle, covered with that ever so soft layer of.....insulation, tend to fair better in cool weather, at least i do. Ree, except for big bubble, no fat at all, freezes up fast. heat....i could definitely take it when i was younger, with no insulation for cool months

on topic with cooling the house, yes, the glass wall would face almost all north, no sun. not ugly, just unconventional. seen a couple around town, with my idea, look rather nice. i may even use the sun, maybe run a lot of pvc on outside as solar water heater. lot of pvc at rental is exposed, almost to the point as the kitchen has hot water, without the water heater. but all exposed areas will be double walled and roofed. probably a flat roof as sitting area, w/steel covering as 2nd roof, shade and rain protection. now, as you say, need to find that lot, w/north exposure, giving me some kind of view, with back of house facing road. that's going to be the hard part, and at a reasonable price. hence the 7 rai in NBLP, that i'll take a peek at, gives me plenty to play with, if in good QUIET location.

Khun Paul and Fremmel are also correct.Heat relates to pressure (more heat=higher pressure.lower heat=lower pressure)so a warmer attic than living area with an insulated ceiling may prevent trapped attic heat being forced through an insulated ceiling.(keep attic heat moving??) The flip-side is that heat gain through walls and windows in the living area would be trapped by the same insulation. As i said earlier,each house and the rooms within are individual to heat gain and AC performance.In this instance there may be no right or wrong but lets hope that all input is considered constructive and assists those requiring the information in their final decisions.Its still a matter of choice.
As for fans disrupting AC air-flow.I recommend no fans outwith the AC.They definately disrupt the air-flow and prevent sensible/real temperature returning to allow the sensor to operate the outdoor unit correctly.I`ve seen this in a smoke test where the AC is running only and there is a constant return to the sensor.Ceiling,wall or floor fan switched on and the smoke is completly distorted and there is lesser or no air return to the sensor.Again,if your more comfortable with fans on its entirely up to yourself,but your electric bills will be higher and compressor lifetime shorter.I wouldn`t recommend it. cheers for now,brian

Even just choosing an apt. Hopefully get one that faces the prevailing wind direction (it makes
a colossal difference if you like to have windows open occasionally. And away from the arc of
the sun so the unit isn't baking all day. Avail yourself of what natural shade is possible. I agree
with Saint & LA that the design/architectural considerations taken into account before building
can alleviate cooling headaches later-on trying a lopsided fight against the forces of nature.

As for fans disrupting AC air-flow.I recommend no fans outwith the AC.They definately disrupt the air-flow and prevent sensible/real temperature returning to allow the sensor to operate the outdoor unit correctly.I`ve seen this in a smoke test where the AC is running only and there is a constant return to the sensor.Ceiling,wall or floor fan switched on and the smoke is completly distorted and there is lesser or no air return to the sensor.Again,if your more comfortable with fans on its entirely up to yourself,but your electric bills will be higher and compressor lifetime shorter.I wouldn`t recommend it. cheers for now,brian

In a correctly placed AC I'm sure your right. But unfortunately, a lot of times they're not correctly placed. Here's an extreme example: an AC placed on a side wall at one end of a long narrow room that has poorly insulated walls (my last rental house). I guess because hot air rises it would get back to the sensor before the cool air at people level warmed up. So the AC would cycle on and make that end of the room uncomfortably cold until the return air cooled off. Without a fan to mix the air the end of the room with the AC would be too cold while the other end got uncomfortably hot. I tried it both ways. With the fan things were pleasant but without the fan they weren't.

The house I built is not nearly as extreme. But with fans the air temperature is more uniform and so more comfortable. Possibly that makes the AC cycle a little more frequently and run shorter periods of time. But even if it is slightly more expensive it corresponds to why I put in ACs in the first place - to keep comfortable. And the increase can't be too much. I just paid last month's electric bill this morning - 1,020 baht for a 4 bedroom house. In the interests of full disclouse , I didn't start using the AC until just before Song Kran about 2 weeks ago. But that's running it in the evening in the living area and all night in the bedroom.

Hi Fremmel.An average 9000 btu & 12,000 btu wall mount unit is designed to throw and return air a max of 7.5 and 9 metres respectively.You should really only feel colder in one area at the beginning of the cycle until temp is maintained throughout the cooled area.I don`t fully understand AC cycling shorter periods of time and and it being more expensive.Maybe we use different terms to mean the same thing.It depends on the compressor (outdoors)being off (off cycle)for as long as possible as this is about 90% of the running cost.Disrupted air-flows usually mean longer run time for the compressor.But hey if your comfortable and "cool" running it that way and your bills continue to remain low.go for it.cheers again Brian.

I was using cycling for the compressor. I leave the fan set on continuous low instead of auto because I don't like the change in noise level and air movement when the compressor cuts in. In my example of my old rental house the room was about 3 m x 5+ m with the AC on the side wall at the end. So the air flow was directed at the opposite wall (yes, I set the vanes in the unit but there wasn't enough travel to really send it down the room). It seemed to me that what happened was the cool air would come out, sink, make it's way to the other end of the room displacing the warm air, which would rise and make it's way back to the unit. But the 20° air from the unit would have cooled that end of the room too cold by the time the return air got cool enough to turn the compressor off. I've never timed the compressor runs with and without the extra fan but I was guessing that with a more uniform air mix the compressor wouldn't run as long to cool down the air. And would start sooner because there wasn't a mass of cooler air next to the sensor. I was also guessing that would shorten the life of the compressor and use more electricity since motor startup is the hardest part of the cycle. But I'm certainly not an aircon engineer so why things are happening and the effect on the compressor is all supposition.

By the way, when using floor fans I don't point them back at the unit but in a direction to help the air flow from the unit, just skewed off to the side, so maybe it's not as distruptive as the setup you're talking about. My units are 9K BTU and 12K BTU so thanks for the additional info. I'll try pointing the vanes of the 9K BTU unit in my 3.5m by 4.5m computer room toward the side wall away from my desk and see if the air bouncing around mixes the air up enough to not need an extra fan.

If won't do much good to have a wall without windows if the wall is getting baked in the sun. Orient your rectangular house e-w, put a large extended porch with overhang on the long s side. Block your entire west end with your carport. Figure out a way to block the brutal morning sun....extended dipping overhangs, large trees, shade cloth, anything to keep the sun off the windows and walls. One option for the east side: no windows and double walls with air gap between.

We lived in our home for 7 years without ceiling insulation (11.5' ceilings). On hot days you could feel the heat radiate down from the ceiling tiles. If we turned on the air midday, it took a few hours to get comfy. With the insulation, the house cools off quickly, and stays reasonable with the ac off when we're out.

If your house is cooler on the inside than the outside, you've got to close your windows during the heat of the day. We generally open the un-ac'd part of the house windows at 6pm and close them at 8am-ish. Same same with patio doors, kitchen doors. Most people open up all their windows and doors during the heat of the day........makes no sense to me.

Trees trees trees trees and remove all that excess concrete around your house. It only serves as a heatsink.

I am much more interested in cooling my outdoor beer garden.
Does any one have any info/specs, on these nozzle types, here in Udon? I'm interested in nozzles that can atomize at least 15-20 microns, or more if possible. Thanks.

doubtful about that system, but the UD tent city food court utilizes the fan type at couple locations. so they should be available here somewhere.

laphanphon wrote:doubtful about that system, but the UD tent city food court utilizes the fan type at couple locations. so they should be available here somewhere.

MACRO has/had fan type misters. Vaguely remember them being priced between 20k-25kbt.