keeping house cool

arjay wrote:I was thinking of the through the wall type extractors, or even the through the ceiling type we have in our shower rooms. Would they not work(fit)? I realise the former have more power and thus move more air.

The big onion type ones, are a bit prominent, and remind me of mosques!!

What do you think of this as an idea:-

1. I get an extractor fan installed in the soffit above the front bedroom balcony (the hot side/corner of the house and being above the balcony easy to get at without ladders) and that extracts the hot air from the roof space.

2. I then get another one installed to the rear of the house, probably in the soffit (?) above the second bedroom balcony (so again, easy to access, and on the cooler side of the house, where the prevailing wind comes from), - this time it draws the air into the roof space to replace what is being extracted at the front. (Though I am not sure whether you can get extractor fans that work the other way round?!)

Ultimately, I guess if you had a reasonable/meaty extractor fan, the air would find it's own way into the roof space through the slots and gaps in the soffits to replace what was being extracted.

3. As an alternative to no 2, I could beef up the ceiling extractor in the main bathroom and/or the en-suite (above the shower) and let that provide replacement air into the roof space.

Then turn both/all such fans on during the daytime hot weather.

Both the en-suite and the main bathroom have small extractor fans pulling air up from above the showers in those rooms and up into the roof space. Currently the roof space is only ventilated by slots in the overhanging roof (soffits?) - those slots face/are parallel with the ground.

Believe or not Arjay I had the same thought, but I didn't think 2 fans would be enough, at least not for our home. Actually my thought was to incorporate both fans and vents. Much like your idea but with the fans forcing air into the attic space and the air escaping though the vents at highest point of the roof.

But in the end I think 1 or 2 roof vents at the apex of roof would be sufficient to allow for some of the trapped hot air to escape.

It's ironic when we are talking about how to keep your house cool, that we should rain, followed by much cooler weather.

I plan to go up and have a look in the roof space tomorrow and see what scope there is for vents fans or whatever!!

i had the idea of the extractor fan in the silver reef .the room size is 28 m.sq. i finally realised the reason i heard a strong draught when i was closing the corridor door was the fact the bathroom extractor fan was on. the fan is in a wall at right angles to the corridor and there is the small bathroom door. arjay if the site for your 2nd fan is protected from rain why not turn the fan around? can not contribute for 3 days have to go to the embassy.

arjay wrote:It's ironic when we are talking about how to keep your house cool, that we should rain, followed by much cooler weather.

I plan to go up and have a look in the roof space tomorrow and see what scope there is for vents fans or whatever!!

yes and also the best time to work in the attic. When I installed the insulation in our home I had to do it in sections, basically one room a day, because it got to hot. This was just before last years hot season.

In a few months time I'll be going back to do another job and that's to unfcuk the electrical wiring connections. Something for you to keep in mind, especially if you're going up for a look. Problem I ran into when putting down insulation was that it sometimes snagged electrical wires [developer to cheap to use proper conduit, wires crissed crossed throughout roof floor space] which in one case shorted out our bedroom recessed lighting system.

Well, I got up in the roof space today, along with the builder's Foreman as we had a water leak.

I must admit to my surprise it wasn't that hot. The Foreman said the same. I assume that the reflective insulation immediately under the roof tiles does its job well. It's always been very hot when I've been up there in the Uk and the ambient temperature here is a lot higher, so I was pleasantly surprised. While the workmen were up there, they carried out some repairs to the reflective foil insulation, which was damaged in a couple of places.

I think the space up there is so large that I doubt installing normal extractor type fans would be sufficient anyway. I plan to check again on a windy day and see if there is air movement up there - I think there is. I'll then give further thought to possibly installing one extractor fan over the front bedroom, as I think air would come in to replace it quite adequately. Alternatively I could lay an insulation blanket over that room only (the main bedroom), thus making the AC more efficient/effective in that location, which is the room that gets the afternoon sun.

Also, I plan to give further thought as to what extent a sun canopy over the front patio windows and wall, might help there.

eutectic bags is the answer

what is a eutectic bag when it is at home ???

Ok, my house is in Australia but the summer temperatures can be the same as Udon. My house is old style Queenslander set high on stumps. This allows free flow of air under the house. The ceilings are 3 metres (10 foot high), floors are wood and there are plenty of doors and windows to allow air flow.

I have a corrugated steel roof with a 50mm foil faced insulation blanket directly under it, R 2.5 ( I do not know how this rating is expressed in the UK or US) fibreglass batts on top of the ceiling. I also have 2 wind powered whirlybird type extractors on the roof. These are the same colour as the roof so not so obtrusive. They spin even on no wind days driven by hot air naturally finding an exit. I have one more whirly bird to install. I am looking for a kit consisting of a ceiling vent (closable), and a length of flexable pipe. This will allow the whirlybird to extract air from the house. I have seen them around here.

For cooling/warming I have reversible ceiling fans in every room plus one pedestal fan.

I think rather than doubling up on thickness of batts (this does not double the R factor) a foil barrier laid on top of the batts would be more efficient. In Austraila there are foil faced cardboard batts avaiable to go on top of fibreglass batts. These are relatively cheap, they are a concertina type of design and when opened are about 30 to 50mm high. The foil radiates heat away from the ceiling and the airspace between the top and bottom of the cardboard batt affords extra insulation. Plenty of information on google re insulation. I also have a lot of tree shade on both the Northern and Western walls.

My house is cool on even the hottest day, cost effective as the fans do not draw a lot of power but is cold in winter. Easy to overcome the cold, sheepskin slippers and extra clothes. By cold I mean 12-18C in daytime during winter.

Just as an aside I found out I can install solar hot water in my house for AUD 1600, about 35K baht at the moment, plus installation. This is due to Australian Government rebates etc.

John

Another factor in Thailand is the fact that the walls of most houses are single skinned, and constructed of basic bricks, thus they have no insulating characteristics and the heat transmits through the wall quickly and easily. Shade from trees and shrubs etc can help reduce that.

The walls of the rooms that get the late afternoon sun stay warm well into the evening.

I'm no expert on keeping a house cool, but I've got 12 years of living in Udon under a variety of conditions to give me some experience. In no particular order, here's some of the things I consider important:

At all costs, keep the sun off your windows and walls. Better than an interior curtain is an external bamboo shade that keeps the sun from hitting the window in the first place. If you don't have trees/overhangs to shade your walls, try experimenting with some of that green/blue shade cloth. Done right, it doesn't have to look too tacky. The western walls in one of the homes we rented downtown was hot well into the evening.

Before we put insulation in our ceiling (4"), we could feel the heat penetrate the gypsum ceiling, despite the ceilings being 11' tall. The insulation put a stop to that.....made a big difference. Our kitchen, which has a lower roof line than the rest of the house used to be unbearable during the heat of the day. Now it's bearable.........not cool, but bearable.

Our experience is: if it's 95 outside and your windows are open, it'll soon be 95 inside. Having experimented with keeping them open/shut, we've found that closing the windows during the day keeps the interior much cooler than with them open. On the negative side, the lack of air movement will make the room feel uncomfortable, even though it'll be cooler than with the windows open. As soon as the heat of the day breaks (around 4), we'll open the windows up and keep them open until 8-9am.

We put in a white rolled-steel roof with a thin layer of insulation attached to the steel. Everything I've read (among many sites, http://www.fsec.ucf.edu/en/ offers lots of suggestions) says white roofs are cool roofs. Thais'll think you're crazy for wanting a white roof........they'll opt for brown/red/blue. Next time you're at one of the big shopping areas during a hot sunny day, put your hand on the roof of a dark car/truck....then put your hand on the roof of a white car/truck.

If you're building a house, put big air vents on either end of the house to allow the hot air to naturally vent out.

Ultimately, though, there's nothing like the dehumidified cool air that an airconditioner provides.

Some good stuff there, - thank you for that Parrot.

Agreed it's better to keep the sun off the windows and walls in the first place, rather than try and reflect it when it's already inside, which is in part what I am doing! I have sun liners on some curtains and blinds, and whilst they do work, obviously in some ways its too late by then, as the heat has already got into the room.

I don't know if they sell it here in thailand but in the USA you can get solar screens which keeps heat out
it was expensive but I had them installed on my windows in Arizona were the heat get to 130+ during July & August and over 100 all summer longer ( mohave valley AZ second hottest spot in the USA )

Does anyone know if they have the solar panels Aznyron refers to, locally?

I believe car windscreen tinting is done by using a thin film applied to the windows. Does anyone know can you do the same to your house windows to cut down the sun/heat? Do any companies locally do such work?

yes you can put it on windows in your home not sure how good it will look a few years down the line if corners come adrift or fine scratch marks through cleaning, or better still if you are having new windows fitted just order tinted/darkened glass,to do a real pro job car window tinters remove the glass..or should remove the glass to get the pro finish...and do not buy rolls of tint and try it yourself..!!

Arjay, not sure if they are available there in the LOS but in the states they use what is called a whole house fan which mounts in the floor of the attic and is louvre covered , when the fan is activated it causes a suction drawing the night cool air in and in turn forces the hot air from the house proper and attic out through vents in the soffits or roof vents. Obviously the fan is large and high powered but the key is having proper ventilation to allow air flow out of the attic, in turn the windows in the house should only be opened a small ammount causing a virtual low pressure into which the cool air rushes. I used to have this in a home in the states and it worked like magic. Cannot see why it would not also work there if you can find the fan system.

I am presently living in the Philippines which has weather just like Thailand, during the day it starts out cool but by evening the house is a heat trap and it does not cool off until about 5am if that. Also here everything is made of concrete and on a slab and many houses have flat roofs which make it even hottter. Insulation is unheard of basicaly, when asked about it most builders just look at you like your nuts. Also here electricity is quite expensive and not very reliable so even your aircon cannot save you some times. If a lighting storm occurs they turn off the power so they don't suffer transformer damages, always a plus on a hot and rainy evening.