Housing heat reduction

[BEVUP]

Hello all

Have read many topics on subject - as i live in a typical 3 bedroom / 2 story Moo Baan house just thought i would discuss some latest thoughts

So have been looking at window film - lets say first

Looked on web for Solar guard Quantum 80 perc heat reduction - for 30 mt x 0.9 mtr roll ( - 11500 bht / add frieght + excise, so lets say for shop a cost of 20,000 bht all up

Went to car tint shop to get quote - Want 200 bht per Sq Foot Installed = 60 000 bht per roll ( i only need 43,000 bht worth)

So that would equate to 30,000 bht for 2 men 1 full day

Second - Whirly birds - Bought 2 from australia ( 250 mm ) as they have many colours & uv rated plastic dome that requires no bearing replacement 3500 bht each

(just need man with long ladder)

Roof Insulation - good question - As i am worried about the power cables over heating since alot of the builders have a tendancy to throw them every where

[Crossy]

If you have space shade plants work well, keeping the sun off the walls is more effective than just shading the windows and plants are cheap.

Venting the attic space is good and effective, don't forget you need to let air in at the bottom to replace that which exits the top.

If you use aircon an insulating layer on top of the ceiling will help, do watch for power cables.

[IMHO]

When it comes to tinting house windows:

1) You only need to tint the windows that get direct sunlight - with particular attention to windows facing to the South and West. Tinting windows that don't get direct sunlight won't achieve much.

2) You want a tint with reflective properties - a lot of car tints are better at cosmetics, creating darkness, and blocking UV/IR than they are at keeping heat out.

3) As an alternative to tint, you might also want to consider specially made heat reflective glass, like Solartag - which is available in a green shade that at least somewhat matches most regular green household glass.

[BEVUP]

Thanks for replying guys

Am thinking of all bases & was wondering if the Eaves that look like aluminium planks ( 1 plain & 1 with looks like many little holes in are actually holes ) or i will get 12 400mm x 200mm eave vents

Crossy your right & there is no avoiding the power as the aircon man (1 in main bdrm - top floor & 1 bottom floor ) took pictures (looking like spahgetti up there ) so am opting for the air flow affect

IMHO have been looking at many properties of film & yes reflective will be an 80 perc heat reduction against maybe max. of 70 perc for Carchoal Hp 60

Wife is worried about reflection as it will look like someone there all the time in the corner of her eye (need more research or sort problem)

[IMHO]

IMHO have been looking at many properties of film & yes reflective will be an 80 perc heat reduction against maybe max. of 70 perc for Carchoal Hp 60

Wife is worried about reflection as it will look like someone there all the time in the corner of her eye (need more research or sort problem)

We use Solartag Plus glass, and have never had anyone think they're seeing ghosts As noted, the green shade of it helps it appear more like normal glass than a mirror... The amount of heat the Solartag rejects is phenomenal - if you open one of our Solartag sliding doors just a bit when the sun's hitting the glass, the difference is immediately noticeable.

Edited June 11, 2015 by IMHO

[carlyai]

IMHO have been looking at many properties of film & yes reflective will be an 80 perc heat reduction against maybe max. of 70 perc for Carchoal Hp 60

Wife is worried about reflection as it will look like someone there all the time in the corner of her eye (need more research or sort problem)

We use Solartag Plus glass, and have never had anyone think they're seeing ghosts As noted, the green shade of it helps it appear more like normal glass than a mirror... The amount of heat the Solartag rejects is phenomenal - if you open one of our Solartag sliding doors just a bit when the sun's hitting the glass, the difference is immediately noticeable.

IMHO,

You gota link for that Solartag Plus glass, or a Thai distributor?

I've got cavity brick, and when the sun is on one of the house end walls, the outside bricks are nearly too hot to touch, but inside brick is cool.

But, have two windows with (green coloured glass, not sure what type as weren't here when windows went in) that get hot.

May be I need to replace the glass with Solartag Plus glass?

[IMHO]

IMHO have been looking at many properties of film & yes reflective will be an 80 perc heat reduction against maybe max. of 70 perc for Carchoal Hp 60

Wife is worried about reflection as it will look like someone there all the time in the corner of her eye (need more research or sort problem)

We use Solartag Plus glass, and have never had anyone think they're seeing ghosts As noted, the green shade of it helps it appear more like normal glass than a mirror... The amount of heat the Solartag rejects is phenomenal - if you open one of our Solartag sliding doors just a bit when the sun's hitting the glass, the difference is immediately noticeable.

IMHO,

You gota link for that Solartag Plus glass, or a Thai distributor?

I've got cavity brick, and when the sun is on one of the house end walls, the outside bricks are nearly too hot to touch, but inside brick is cool.

But, have two windows with (green coloured glass, not sure what type as weren't here when windows went in) that get hot.

May be I need to replace the glass with Solartag Plus glass?

Its made by AGC, so practically every window shop in Thailand has access to it.

http://www.agc-flatglass.co.th/product.php?Cat=2&Sub=4&Id=35

We have ~28sqm of glass that has no option but to face S-SE - Solartag was a life saver for us. Incredible reduction of the amount of heat coming in.

Edited June 12, 2015 by IMHO

[Crossy]

Solartag looks interesting.

Can it be cut on-site or does it need to be ordered to size?

[IMHO]

Solartag looks interesting.

Can it be cut on-site or does it need to be ordered to size?

Assuming you don't order the tempered version, cut on site just like normal float glass.

[Laza 45]

I used solar reflective glass in windows installed in a two story extension to our old house.. seems to work quite well. I used aluminium roofing with attached insulation and also installed insulation above upstairs ceilings to minimize radiated heat and the roof cools down quickly when the sun goes off it.. the roof on the old part of the house has cement tiles and no insulation.. like being in a toaster on a hot day! Downstairs in the new part I built cavity walls.. insulating block on outside.. conventional cement block inside.. upstairs one layer insulating block.. to keep load down.. downstairs stays relatively cool all day and is comfortable with fans... no aircon.. upstairs cools down reasonably quickly in the evening.. Good airflow through roof space is very important .. oh.. verandas along sunny walls to protect the walls from direct sun helps too..

The suggestion to put plants against sun exposed walls is a good one I think.. Bougainvillea might work well... any other suggestions?

[Crossy]

Bougainvillea can get out of hand very quickly and most varieties have spikes, but it looks nice and can be trained.

Bananas work well if you have the space, fast (very) growing, huge, shady leaves and they produce fruit, too much fruit in our case. But they're not particularly decorative.

We have loads of room so several mango trees are maturing (not too close to the house but still offering shade as the sun sets).

We also have many plants of assorted types in containers which Wifey moves around at random, the ones on the upstairs patio provide a marvellous cooling effect by absorbing the heat reflected off our white walls.

IMHO You can never have too much greenery.

[technologybytes]

i have installed roof insulation a number of time, most recently this week, and it's always worked remarkably well and is very good value. The price of the thick good roof insulation is 196 baht per 2.4 sqm roll. if you have a single story house then it's a no brainer. Every 100 sqm of roof space costs just 8000 baht, plus 500-1000 baht for a slim lad to climb into the roof space and install it.

The window film will work well for windows that get direct sunlight, but so will closing the curtains especially if you have a thermal lining on the curtains. I prefer having some trees to shade the windows.

The big issue with Thai houses is the brick walls that warm up all day and then become massive radiators for hours after the sun has gone down, you know that when in the evening it is cooler outside than it is in the house. I just built a cavity wall in our kitchen to deal with that problem.

If you can't afford roof insulation then a ventilation fan in the roof space can work well, but insulation is better.

Edited June 12, 2015 by technologybytes

[Mudcrab]

When I worked on shift I did the bedroom windows with aluminium foil (the cooking type) and sticky tape. Kept the light and heat out.!

Not pretty but very effective and cheap.

[mikemac]

We all seem to have our own favorite way of cooling our house.

The reflective material you stick on the window glass looks good and I will be looking into that.

I built a house in Australia years ago and put an exhaust fan in the top of the gable end on the western end of the house. It blew all the hot air out of the roof area. Made a big difference to the temp of the house.

We just had a new house built at Saraphee which has four gable ends. I will probably put one fan in one gable end blowing air into the roof cavity and fans in two of the other gable ends blowing air out.

[BEVUP]

All sound like great ideas but as we know it depends on what extremes we go to for best value

As we know the walls are of those small red clay bricks & rendered (acting like the roof tiles) so trees would be best option but difficult in Moo Baan & certainly can not afford to reline a 2 story place

The main concern is upstairs so out of all of the suggestions i am thinking of Whirly Birds & maybe adding vents to eaves even though the material they used have many tiny holes (which look like they dont draw much breeze in )

Have vertical blinds upstairs of reasonably good quality from Home Pro (so will wait on the film )

Would like to put in the roof/ceiling insulation - but as Crossy said Watch out for the cables

So question for Crossy on installation

How bad would the effect be if cant avoid cables & do the installation men (lets say Home Pro ) know to cut out for light fittings / ect

Thanks for all joining discussion as i wanted to update the window film bit for others after reading many other threads

Ps - I would of certainly had this covered if building from scratch

[bluejets]

Whirlybirds are not worth a cracker at removing heat.

Was advised by engineer that a chimney style tube with a "hat" creates much more draft and after having one of the former (whirlybirds) fitted in my workshop, I tend to agree.

[Laza 45]

Whirlybirds are not worth a cracker at removing heat.

Was advised by engineer that a chimney style tube with a "hat" creates much more draft and after having one of the former (whirlybirds) fitted in my workshop, I tend to agree.

Good idea!.. maybe a fan forcing air in and a vent like you describe to let it out would work well..

[Ghostnigel]

Can i ask, or am i missing something, but why wouldn't the electric wires be better under the insulation? It will still be very hot inside the roof space, but if the insulation does its job, underneath should be cooler.....anyone got an answer for me?

[Crossy]

Can i ask, or am i missing something, but why wouldn't the electric wires be better under the insulation? It will still be very hot inside the roof space, but if the insulation does its job, underneath should be cooler.....anyone got an answer for me?

The wires themselves generate heat when carrying current, this heat has to go somewhere or the wire (actually the insulation) will overheat.

Most domestic style cable is intended to run with the conductors at 70^oC max (pretty warm) and will be at that temperature when carrying its rated current in free air. Cover it in insulation and the heat cannot escape, you need to de-rate (reduce the max current) by 50% or more.

[Ghostnigel]

Can i ask, or am i missing something, but why wouldn't the electric wires be better under the insulation? It will still be very hot inside the roof space, but if the insulation does its job, underneath should be cooler.....anyone got an answer for me?

The wires themselves generate heat when carrying current, this heat has to go somewhere or the wire (actually the insulation) will overheat.

Most domestic style cable is intended to run with the conductors at 70^oC max (pretty warm) and will be at that temperature when carrying its rated current in free air. Cover it in insulation and the heat cannot escape, you need to de-rate (reduce the max current) by 50% or more.

Thanks Crossy, for the input, but wouldn't the wires do the same (overheat) sitting on top of alluminium foil, with the heat of the roof space around it? You must be right, but i'm still confused.

[Ghostnigel]

I am getting it done, waiting for a date...but i don't know if i can trust them to do it correctly now. If they do it wrong, i'd be looking up at the ceiling waiting for it to catch fire...gulp!

[Crossy]

Can i ask, or am i missing something, but why wouldn't the electric wires be better under the insulation? It will still be very hot inside the roof space, but if the insulation does its job, underneath should be cooler.....anyone got an answer for me?

The wires themselves generate heat when carrying current, this heat has to go somewhere or the wire (actually the insulation) will overheat.

Most domestic style cable is intended to run with the conductors at 70^oC max (pretty warm) and will be at that temperature when carrying its rated current in free air. Cover it in insulation and the heat cannot escape, you need to de-rate (reduce the max current) by 50% or more.

Thanks Crossy, for the input, but wouldn't the wires do the same (overheat) sitting on top of alluminium foil, with the heat of the roof space around it? You must be right, but i'm still confused.

In a way you are correct, you have to de-rate cables when the ambient temperature is high (like your nice toasty attic) but the effect is significantly less than burying the cable in insulation.

If you're interested have a Google for de-rating tables and compare say, an ambient of 50^oC (not unlikely in Thailand) and 6" of fibre insulation.

[Ghostnigel]

Can i ask, or am i missing something, but why wouldn't the electric wires be better under the insulation? It will still be very hot inside the roof space, but if the insulation does its job, underneath should be cooler.....anyone got an answer for me?

The wires themselves generate heat when carrying current, this heat has to go somewhere or the wire (actually the insulation) will overheat.

Most domestic style cable is intended to run with the conductors at 70^oC max (pretty warm) and will be at that temperature when carrying its rated current in free air. Cover it in insulation and the heat cannot escape, you need to de-rate (reduce the max current) by 50% or more.

Thanks Crossy, for the input, but wouldn't the wires do the same (overheat) sitting on top of alluminium foil, with the heat of the roof space around it? You must be right, but i'm still confused.

In a way you are correct, you have to de-rate cables when the ambient temperature is high (like your nice toasty attic) but the effect is significantly less than burying the cable in insulation.

If you're interested have a Google for de-rating tables and compare say, an ambient of 50^oC (not unlikely in Thailand) and 6" of fibre insulation.

ok Crossy, I will take a look....but i cannot promise you i will understand it, I've never been able to get my head round electricity thingies, i can do chippying and plumbing, (a little water can't kill yer) but 'lectric scares me.

I really wanted to know so that i don't get ripped off by the installers when they fit the insulation, didn't know what to look out for. At least now, i can make sure they put the wires on top, and know why....555

[Crossy]

ok Crossy, I will take a look....but i cannot promise you i will understand it, I've never been able to get my head round electricity thingies, i can do chippying and plumbing, (a little water can't kill yer) but 'lectric scares me.

I really wanted to know so that i don't get ripped off by the installers when they fit the insulation, didn't know what to look out for. At least now, i can make sure they put the wires on top, and know why....555

I wouldn't worry about wires to lights, they are so oversized there wont be an issue. Wires to thirsty appliances are what you need to look after, water heaters, aircon etc etc.

If you have any downlighters that will get covered they will need some sort of box to keep the insulation well away from the hot lamp and allow the heat to escape.

[Ghostnigel]

ok Crossy, I will take a look....but i cannot promise you i will understand it, I've never been able to get my head round electricity thingies, i can do chippying and plumbing, (a little water can't kill yer) but 'lectric scares me.

I really wanted to know so that i don't get ripped off by the installers when they fit the insulation, didn't know what to look out for. At least now, i can make sure they put the wires on top, and know why....555

I wouldn't worry about wires to lights, they are so oversized there wont be an issue. Wires to thirsty appliances are what you need to look after, water heaters, aircon etc etc.

If you have any downlighters that will get covered they will need some sort of box to keep the insulation well away from the hot lamp and allow the heat to escape.

Ok boss, i will make sure its done....thanks for taking time to answer to me, puts my mind at rest.

[Laza 45]

I don't like to be alarmist but thought I'd pass this along.. after the last big global financial crisis the Australian government embarked on some stimulus programs.. one was to provide subsidized roof insulation.. to provide jobs and to cut down on energy use.. and was very successful in those ways.. but... there were a few problems with such a program being introduced very quickly.. many people were put to work doing the installations who were not properly qualified... one type of insulation used was sheet foil.. spread across rafters.. several installers (young inexperienced guys) were electrocuted.. they were stapling the foil with metal staples and inadvertently stapled into electrical wiring. !! also there were a number of house fires attributed to improperly installed insulation.. most, I believe because care wasn't taken around light fittings.. as suggested above.. use a 'box' barrier around lights.. especially any halogen lights.. they get extremely hot.. There were many thousands of homes fitted with insulation under this program and the catastrophes relatively few.. but worth mentioning.. I think..

[mike324]

Whirlybirds are not worth a cracker at removing heat.

Was advised by engineer that a chimney style tube with a "hat" creates much more draft and after having one of the former (whirlybirds) fitted in my workshop, I tend to agree.

Good idea!.. maybe a fan forcing air in and a vent like you describe to let it out would work well..

Just to throw some info out there, I saw a solar power fan roof fan for sale on sukhumvit road, between BTS Phrompong and BTS Thonglo station. Shop is called 200 Volts.

One could probably reverse the fan so one blow air in and the other sucks air out. I would imagine if you are blowing air in you will have a lot of dust in the ceilings. Foil insulation would probably be the best option for roofs.

[adney02]

I will take a look.

But i cannot promise you i will understand it.

I have never been able to get my head round electricity thingies.

I can do chippying and plumbing, but lectric scares me.

[mickba]

IMHO have been looking at many properties of film & yes reflective will be an 80 perc heat reduction against maybe max. of 70 perc for Carchoal Hp 60

Wife is worried about reflection as it will look like someone there all the time in the corner of her eye (need more research or sort problem)

We use Solartag Plus glass, and have never had anyone think they're seeing ghosts As noted, the green shade of it helps it appear more like normal glass than a mirror... The amount of heat the Solartag rejects is phenomenal - if you open one of our Solartag sliding doors just a bit when the sun's hitting the glass, the difference is immediately noticeable.

IMHO,

You gota link for that Solartag Plus glass, or a Thai distributor?

I've got cavity brick, and when the sun is on one of the house end walls, the outside bricks are nearly too hot to touch, but inside brick is cool.

But, have two windows with (green coloured glass, not sure what type as weren't here when windows went in) that get hot.

May be I need to replace the glass with Solartag Plus glass?

Its made by AGC, so practically every window shop in Thailand has access to it.

http://www.agc-flatglass.co.th/product.php?Cat=2&Sub=4&Id=35

We have ~28sqm of glass that has no option but to face S-SE - Solartag was a life saver for us. Incredible reduction of the amount of heat coming in.

For an existing house/condo' I presume that you are talking about replacing the old glass with Solartag.

Any thoughts on using it as an additional layer inside the existing glass (AKA secondary/double glazing) ?

Wouldn't that stop even more heat transfer?

[IMHO]

For an existing house/condo' I presume that you are talking about replacing the old glass with Solartag.

Any thoughts on using it as an additional layer inside the existing glass (AKA secondary/double glazing) ?

Wouldn't that stop even more heat transfer?

Correct - if you have windows/glass doors that get direct sunlight, replacing the existing glass with solartag will give you a huge reduction in heat that gets into the room.

If you were going to use solartag for double glazing, you'd want to make it the outside layer, not the inside layer though. The actual glass itself still gets warm/hot under direct sunlight - i.e. what it doesn't reflect it still absorbs.