Detached Singe House & Heat

[depe]

We are planning to buy a new two floor detached single house in one of the “moo baans” in Bangkok. There are of course many things that concerns me, but the current issue is the heat. I would like to gather some experiences or recommendations from people who are living in this kind of two floor single houses. How hot does it get and what to do with it?

I’ve been living in Bangkok several years now, so the tropical heat is nothing new to me. Anyhow, we’ve been living in few different town homes with three floors. In those the first floor has been actually quite pleasant. You can easily spend time there with a strategically positioned floor fan and without AC. Even the second floor is not that bad, but I tend to use the AC, if I need to spend more time there (=during nights). The third floor gets quite hot during the day. The AC is almost a must at least now in the hot season. In general I just like that fact that the first/ground floor, where we spend most of the time, is not really hot at all and we don’t need to use the AC.

We have now visited many new houses, and it strikes me how HOT it is inside. I am speaking about the empty houses, not the furnished sample houses with ACs turned on. Of course there are no curtains, the windows have been closed etc. so it is not a realistic situation. Anyhow, the facts are that there is no third floor, where the hot air could “escape”, the houses are pretty much under direct sunlight (no big trees for shading), etc.

So, people living in this kind of single houses, what are you experiences? Can you compare the single houses and town homes? Any recommendations? Is there something to check, when visiting the houses to evaluate them with this angle? Just to be clear of course ACs will be installed in every room, but I would like to avoid using them as much as possible, and in general I don’t want to live in an oven.

[Pib]

I've lived in a two story detached home for 8 years here in western Bangkok. Sure, the second story gets pretty warm due mid day to sundown, but we actually don't spend much time during the day in the second story during that period...the second story is all bedrooms (well I use one as an office that I don't use that much) and two baths. At night we just turn the room A/C on...cools down nicely within 10 minutes.

I expect the new houses you have been visiting only turn the A/C on just before you might get there or if a model home for show they don't set the A/C to cool purely because A/C eat a lot of electricity....and Thais usually can deal with higher heat better than most farangs. Or the new homes you are looking at don't even have room A/Cs installed yet? And for the most part, since by far Thais are the biggest buyers of homes in Thailand, they are generally much more use to/more comfortable in higher heat than most farangs. Heck, my Thai neighbors in the house right next to me have multiple A/Cs but they rarely any of them---even at this time of year when it's really HOT!! Yes, yes, I know many Thais like A/C also but all my Thai friends, neighbors, and family use A/Cs much less than I do (and my spoiled Thai wife who has got use to A/C 24/7). For most they just have windows open, fans running, and A/Cs turned off.

I also expect your townhouse was significantly smaller in size than the homes you are looking at and of course unless your townhouse was an end unit it effectively had shade on both sides from the other units....and a smaller roof size to suck up the sun than a detached home.

But yea, unless a detached home happened to have some shade trees around it or partially in the shadow of another home, that a detached home would generally get warmer than a townhouse/condo.

[depe]

I've lived in a two story detached home for 8 years here in western Bangkok. Sure, the second story gets pretty warm due mid day to sundown, but we actually don't spend much time during the day in the second story during that period...the second story is all bedrooms (well I use one as an office that I don't use that much) and two baths. At night we just turn the room A/C on...cools down nicely within 10 minutes.

I expect the new houses you have been visiting only turn the A/C on just before you might get there or if a model home for show they don't set the A/C to cool purely because A/C eat a lot of electricity....and Thais usually can deal with higher heat better than most farangs. Or the new homes you are looking at don't even have room A/Cs installed yet? And for the most part, since by far Thais are the biggest buyers of homes in Thailand, they are generally much more use to/more comfortable in higher heat than most farangs. Heck, my Thai neighbors in the house right next to me have multiple A/Cs but they rarely any of them---even at this time of year when it's really HOT!! Yes, yes, I know many Thais like A/C also but all my Thai friends, neighbors, and family use A/Cs much less than I do (and my spoiled Thai wife who has got use to A/C 24/7). For most they just have windows open, fans running, and A/Cs turned off.

I also expect your townhouse was significantly smaller in size than the homes you are looking at and of course unless your townhouse was an end unit it effectively had shade on both sides from the other units....and a smaller roof size to suck up the sun than a detached home.

But yea, unless a detached home happened to have some shade trees around it or partially in the shadow of another home, that a detached home would generally get warmer than a townhouse/condo.

We have visited both the model/sample houses (with A/C on) and the empty ones without any furniture & non-existing A/C. I am now speaking about the empty houses that concern me. As I said, the situation is not realistic, since there are no curtains in windows, and most likely all the windows have been closed and the house has been heating up perhaps several days on row.

Yes, and you are right about the town homes I have lived in. They have not been the end unit, so the wall exposure to sun has been quite minimal. It is actually quite amazing how cool the 1st floor can be - even now during the hottest season.

There is actually quite a few nice threads about cooling houses in the "DIY & Housing" forum. I need to read those carefully. Basically I am just afraid if there could be some bad house design issues that could lead to major heat problem. And if there are, what kind of things I could check before doing any decisions. And of course it might be possible that even with the best possible design and by using all the possible tricks to make the house cooler, it will never be exactly cool compared to the homes I used to live.

[keeniau96]

If your target house is not a flat roof but has an airspace above the top floor then cross-ventilation with an attic fan is a simple and very effective relief. You need openings on both ends for inflow and exit air, best use barred and screened cover to keep out vermin. Have a switch on top or bottom floor and just remember to turn it on and off, or put on timer. Check the fan for quiet running and mount with rubber blocks or washers to cut vibrations.

[fredge45]

If your target house is not a flat roof but has an airspace above the top floor then cross-ventilation with an attic fan is a simple and very effective relief. You need openings on both ends for inflow and exit air, best use barred and screened cover to keep out vermin. Have a switch on top or bottom floor and just remember to turn it on and off, or put on timer. Check the fan for quiet running and mount with rubber blocks or washers to cut vibrations.

In addition to the attic ventilation be sure to check on having at least 15 cm (6") foil backed insulation in the floor of the attic (therefore on the ceiling of the 2nd floor rooms). Makes a huge difference!

[thai3]

One reason is modern houses are full of windows, far too many of them letting in the heat. Then people have the curtains drawn all day, so what's the point? Roof space, 6 inch insulation and some sort of air flow is a big help. Plus better paint on the outside, builders usually only use cheaper 4 seasons or similar, something better will reflect the heat a bit and stop the walls heating up like a battery in the day, shade from extra roofs and trees of course and lots of a/c.

Edited April 11, 2016 by thai3

[depe]

Thanks everyone for answers. There were some really good points.

If your target house is not a flat roof but has an airspace above the top floor then cross-ventilation with an attic fan is a simple and very effective relief. You need openings on both ends for inflow and exit air, best use barred and screened cover to keep out vermin. Have a switch on top or bottom floor and just remember to turn it on and off, or put on timer. Check the fan for quiet running and mount with rubber blocks or washers to cut vibrations.

The search still continues, but the few houses we have been interested in had the "pyramid shape" roof, so there is airspace above the top floor. Not sure how to setup a ventilation for this kind of roof. Anyhow, first things first, I need to check whether the roof air space is actually hot in the afternoon/evening.

[thai3]

How could it not be hot?

[CousinEddie]

To keep my place cool, I run the air conditioner. About 3,000Bt. a month.