Living In The Philippines Forum

Itís Your Money => Building in the Philippines => Topic started by: Palawan Aussie on May 14, 2013, 10:09:41 PM

Title: Passive Cooling
Post by: Palawan Aussie on May 14, 2013, 10:09:41 PM
Frosty writes,

Quote
It sounds like insulation is an after thought when building a house. What has everybodying been using to insulate the outside walls?



There's good information regarding passive-cooling here .. in fact, the whole website is excellent ..

http://www.builditsolar.com/Projects/Cooling/passive_cooling.htm (http://www.builditsolar.com/Projects/Cooling/passive_cooling.htm)


For example, here's a simple research initiative that people might like ..  (I wouldn't use lime on an aluminium or tin roof though)

http://www.builditsolar.com/Projects/Cooling/WhiteRoofExperiment/WhiteRoof.htm (http://www.builditsolar.com/Projects/Cooling/WhiteRoofExperiment/WhiteRoof.htm) (snipped)

From David: My roof needs replacing anyway, so I thought I would do an experiment to see the effects of painting it WHITE. I have already placed digital thermometers in the attic for previous experiments so I could easily monitor progress.

I started off with a product made for the purpose... a highly reflective "elastomeric" roof coating. However, a 5 gallon bucket of this product costs $60.00. I figured I needed TEN of those 5 gallon buckets to cover my 1300 square foot roof. That put the cost up around $600 dollars. TOO MUCH MONEY for a little experiment.

So I opted for the EL-CHEAPO method of using HYDRATED LIME mixed with 50% water to do the job. Two bags of Hydrated Lime cost $14.00 total!!  It is available in the concrete department of any hardware store for $7.00 per 50 pound bag. This stuff goes on kinda GRAY looking when it is wet. But when it dries it is BRILLIANT WHITE.
 
Lime kind of burns your skin, so don't get it on your skin or eyes. I did all the mixing right on the roof so I wouldn't have to lug all that water up the ladder. Just kept the water hose running while  worked. Painting was easier by just dumping a gallon or so at a time right on the roof and just rolling it evenly. It took about 6 hours of work to accomplish the task.

Here are the results of this experiment: Attic temperatures were reduced by about 30 to 40 degrees.... and house temperatures were reduced about 8 or 10 degrees. Some folks might think 8 or 10 degrees isn't much... but, it is right on the edge where we don't even need to run the air conditioner! I personally would not use AC at all.... but the wife still likes it ON occasionally.

If a simple home-owner like me can accomplish reducing my attic temperature by 40 degrees by using fourteen dollars worth of paint... why cant these roofing companies come up with something that can reflect the heat without breaking my bank account?

It has rained a couple times since painting... and the lime seems to be holding on OK and not rinsing off. Don't paint if its going to rain in the next 24 hours though. ONE neighbor asked what i was doing. I explained I was "coating my roof with special reflective coating" to reduce air conditioning costs. If he had objected, I would have mentioned that president Obama recommended doing this in one of his speeches!  Right now, this looks "unusual"... but in a few years i believe white roofs will be very common to reduce greenhouse gases and electric bills. One village in Greece has ALL their roofs white.


(http://www.builditsolar.com/Projects/Cooling/WhiteRoofExperiment/WhiteR12.jpg)


Title: Re: Passive Cooling
Post by: Art, just a re(tired) Fil-Am on May 14, 2013, 10:47:58 PM
It all sounds and looks practical, but who would want an all white roof that doesn't fit the scheme/theme of one's subdivision, unless one lives in Greece or on the Greek Isle of famous Santorini where everything is all white washed, except for a few blue dome roofs!
We're in the Philippines and anything is possible, if one wants it to be and where there are no restrictions!   

https://www.google.com.ph/search?q=pictures+of+santorini+greece&rlz=1C1FDUM_enPH474PH476&tbm=isch&tbo=u&source=univ&sa=X&ei=W06SUbLkD8iZiAeU0YDYBA&ved=0CCkQsAQ&biw=1120&bih=635
Title: Re: Passive Cooling
Post by: paulgee on May 17, 2013, 03:00:25 AM
Our sub division has red, blue, orange and brown roofs on the houses. We went for the whitest roof they did, which is a creamish colour.
Not sure what difference it makes, but one can only try.

Paul

Title: Re: Passive Cooling
Post by: Frosty on May 17, 2013, 12:46:38 PM
I think the lighter colour roof is a great idea, maybe not white but a light gray or tan maybe even a light blue.

Did you notice the roof vents thats another good idea, you don't want to trap all that hot air in the attic space it needs away out.
My brother put in a solar attic fan he told me it works great in the summer to help cool the house.
Title: Re: Passive Cooling
Post by: wildbill on May 17, 2013, 07:18:11 PM
no need to insulate the outer walls of most houses in the philippines because they are made of cement hollow blocks etc...:)
Title: Re: Passive Cooling
Post by: paulgee on May 17, 2013, 07:53:16 PM
Our house was built in our absence, with only family there to check things out. So we had no chance to do anything more about insulation etc. When we are there full time I hope that we can do something retrospectively to vent the roof space, or cover the ceiling there with insulation.

As I remember it the ceiling structure was composed of  thin metal struts, as picture below. I am not sure one could crawl round the loft space supported by them!

Paul

Title: Re: Passive Cooling
Post by: Tally J on May 17, 2013, 09:20:04 PM
The builder is currently installing the furring strips to hold the gypsum board for the ceiling in the house I am having constructed.  I am trying to get them to install insulation while this is being done as the ceiling supports are certainly not strong enough to support my "excess" weight.  I am still running into resistance "as this is not the way it is done here" not to mention having a hard time locating insulation that is at least 3 to 6 inches thick rather than the 3-4 mil they will install.  The insulation will make a significant difference in the inside temperature on the second floor of the house.

I have my brother-in-law trying to track some down for me though.
Title: Re: Passive Cooling
Post by: wildbill on May 17, 2013, 10:07:11 PM
Tally Colin says they have the thick insulation in CITI hardware but im still looking around no citi here where I live I will posts it if I find any
Title: Re: Passive Cooling
Post by: Tally J on May 17, 2013, 10:54:48 PM
Thanks Widlbill.

House in the Angeles city area. I Googled CITI but there does not appear to be a location in the Angeles area.  Cannot locate insulation on the Wilcon, Home Depot or Federal web sites so that is why I asked my brother-in-law to see if he could locate some.  Building is hard to do long distance.

I may just have to buy it here in US and then ship it along with my household goods.
Title: Re: Passive Cooling
Post by: Gray Wolf on May 18, 2013, 12:34:44 AM
no need to insulate the outer walls of most houses in the philippines because they are made of cement hollow blocks etc... :)

Typical hollow blocks act as heat sinks and will retain heat built up during the day well into the evening hours.  I know of several people who have added sheets of foam insulation to the interior walls to reflect that heat away from the interior.  Some have even used foam insulation on the outside of the walls to prevent the heat from building up in the first place. 

Colin, and others, used thick foam panels in construction in lieu of concrete walls.  They were then skim coated with a thin layer of concrete to add solidity to the walls.

"It's not done here" is a typical response given by builders in the Philippines.  But keep in mind, these same people think that temperatures in the 70's (20'sC) are "nippy".  Go figure.   ;)

Insulation, both foam and fiberglass, is available in the Philippines.  You just have to do some work to find the proper supplier.
Title: Re: Passive Cooling
Post by: Frosty on May 18, 2013, 09:21:07 AM
GW your right about block walls heating up during the day, without any insulation to prevent the walls from heating up the air con will need to work over time to keep up with the outside tempture.
Title: Re: Passive Cooling
Post by: wildbill on May 18, 2013, 09:24:19 PM
Yes it does heat my outside walls as well some times I put the hose pipe to work in the afternoon just to try an cool the wall down.
Title: Re: Passive Cooling
Post by: Frosty on May 19, 2013, 10:24:29 PM
My brothers and I built my parents house. 3 of my brothers are engineers and they all thought they were the boss,and they were all a pain in my a_ _, anyways back to my point. one of my brothers figured out where the sun was during the different seasons of the year. Winter time the sun is low in the sky the windows on the south side of the house were placed so they got the max amount of sun light. In the summer they figured out how to keep the wall on the south side of the house in the shade by the overhang of the eve, we ended up with a 2 foot overhang for our location, only the bottom of the wall gets any sun during the day this is not a big deal it helps with light in the basement and the basement is always cooler.
I was thinking that before anyone starts to build they should take a tape measure and walk around and check out the shadows on walls and where the sun is hitting the wall. In the long run it will save money on the power bill.

Wildbill
Have you thought about some kind of water mist, I've seen them down in Las Vegas outside where people are walking around it helps to cool them off
Title: Re: Passive Cooling
Post by: wildbill on May 20, 2013, 09:51:37 PM
water mist no I havent but thanks it would really help I think
Title: Re: Passive Cooling
Post by: BingColin on May 23, 2013, 07:44:34 AM
I have been away for a few days visiting El Nido so have not been able to respond until now.

I think it important to insulate walls even if you are not planning to use much aircon. Take a look at this section of my web site. http://thephilippinejournal.wetpaint.com/page/Design (http://thephilippinejournal.wetpaint.com/page/Design)  We use very little aircon and the house is noticeably cooler most of the time even with the windows open. A hollow block wall has an R value of around 1.0 and my 3 inch polystyrene walls around 11.0. That is 11 times better; they are cold even if the sun is on them all day. If you want to use aircon then you will have a big reduction in electricity bills. We only have fans in the lounge and master bedroom, but I do use a small aircon more often in my study. There are other aspects of house design that you need to consider to make it comfortable, and I cover them on my web site.

Whatever you do with the walls, it is essential to insulate the attic space and give lots of ventilation. We used 6 inch foil bags filled with fibreglass from Citi Hardware, but they then stopped stocking it at our local store. You should be able to buy the rolls of fibreglass at building supply stores.
Title: Re: Passive Cooling
Post by: paulgee on May 23, 2013, 09:30:20 PM
Our house is a standard sub division property - hollow blocks and no roof insulation.

We can do nothing about the walls but if we stay there long term in future we will get some roof insulation.

During the 3 months we were there last year we used aircon but as frugally as possible and I think the cost would be manageable, especially as we have split aircon which is cheaper to use though more expensive to buy. And the Sep-Dec time we spent there was not the hottest time of the year, so that would have to be taken into account.

Paul
Title: Re: Passive Cooling
Post by: rayhigh on May 15, 2014, 09:21:07 PM

Hello Colin,

I'm new here.  What is the address of your website?

Thanks!

I have been away for a few days visiting El Nido so have not been able to respond until now.

I think it important to insulate walls even if you are not planning to use much aircon. Take a look at this section of my web site. [url]http://thephilippinejournal.wetpaint.com/page/Design[/url] ([url]http://thephilippinejournal.wetpaint.com/page/Design[/url])  We use very little aircon and the house is noticeably cooler most of the time even with the windows open. A hollow block wall has an R value of around 1.0 and my 3 inch polystyrene walls around 11.0. That is 11 times better; they are cold even if the sun is on them all day. If you want to use aircon then you will have a big reduction in electricity bills. We only have fans in the lounge and master bedroom, but I do use a small aircon more often in my study. There are other aspects of house design that you need to consider to make it comfortable, and I cover them on my web site.

Whatever you do with the walls, it is essential to insulate the attic space and give lots of ventilation. We used 6 inch foil bags filled with fibreglass from Citi Hardware, but they then stopped stocking it at our local store. You should be able to buy the rolls of fibreglass at building supply stores.
Title: Re: Passive Cooling
Post by: BingColin on May 15, 2014, 09:38:52 PM

Hello Colin,

I'm new here.  What is the address of your website?

Thanks!

I have been away for a few days visiting El Nido so have not been able to respond until now.

I think it important to insulate walls even if you are not planning to use much aircon. Take a look at this section of my web site. [url]http://thephilippinejournal.wetpaint.com/page/Design[/url] ([url]http://thephilippinejournal.wetpaint.com/page/Design[/url])  We use very little aircon and the house is noticeably cooler most of the time even with the windows open. A hollow block wall has an R value of around 1.0 and my 3 inch polystyrene walls around 11.0. That is 11 times better; they are cold even if the sun is on them all day. If you want to use aircon then you will have a big reduction in electricity bills. We only have fans in the lounge and master bedroom, but I do use a small aircon more often in my study. There are other aspects of house design that you need to consider to make it comfortable, and I cover them on my web site.

Whatever you do with the walls, it is essential to insulate the attic space and give lots of ventilation. We used 6 inch foil bags filled with fibreglass from Citi Hardware, but they then stopped stocking it at our local store. You should be able to buy the rolls of fibreglass at building supply stores.



Hi Ray, my website used to be with 'wetpaint' but they seem to have changed hands and it is now http://thephilippinejournal.wikifoundry.com/ (http://thephilippinejournal.wikifoundry.com/).

We have now installed aircon in our bedroom and have it set to 26C. Our electricity bill does not seem to be any higher than when we used a fan, and as long as you keep the doors closed it remains cooler for most of the day.
Title: Re: Passive Cooling
Post by: rayhigh on May 15, 2014, 09:46:22 PM

Colin,

Thanks so much for the updated link.  We are determined to build our place to keep as cool as possible - I really want to avoid $300/month electricity bills!

Best,

R


Hello Colin,

I'm new here.  What is the address of your website?

Thanks!

I have been away for a few days visiting El Nido so have not been able to respond until now.

I think it important to insulate walls even if you are not planning to use much aircon. Take a look at this section of my web site. [url]http://thephilippinejournal.wetpaint.com/page/Design[/url] ([url]http://thephilippinejournal.wetpaint.com/page/Design[/url])  We use very little aircon and the house is noticeably cooler most of the time even with the windows open. A hollow block wall has an R value of around 1.0 and my 3 inch polystyrene walls around 11.0. That is 11 times better; they are cold even if the sun is on them all day. If you want to use aircon then you will have a big reduction in electricity bills. We only have fans in the lounge and master bedroom, but I do use a small aircon more often in my study. There are other aspects of house design that you need to consider to make it comfortable, and I cover them on my web site.

Whatever you do with the walls, it is essential to insulate the attic space and give lots of ventilation. We used 6 inch foil bags filled with fibreglass from Citi Hardware, but they then stopped stocking it at our local store. You should be able to buy the rolls of fibreglass at building supply stores.



Hi Ray, my website used to be with 'wetpaint' but they seem to have changed hands and it is now [url]http://thephilippinejournal.wikifoundry.com/[/url] ([url]http://thephilippinejournal.wikifoundry.com/[/url]).

We have now installed aircon in our bedroom and have it set to 26C. Our electricity bill does not seem to be any higher than when we used a fan, and as long as you keep the doors closed it remains cooler for most of the day.
Title: Re: Passive Cooling
Post by: BingColin on May 16, 2014, 08:04:04 AM

Colin,

Thanks so much for the updated link.  We are determined to build our place to keep as cool as possible - I really want to avoid $300/month electricity bills!

Best,

R


Hi Ray, I would recommend that you consider 'Inverter' aircons, they are cheaper to run. I think they are only made in the split type which are a lot quieter that the window/wall type anyway. We favour the Samsung aircons, and other things, they are very good and less expensive than some other brands.

We have a 2hp split type inverter in the kitchen a 2.5hp in the bedroom. They are use quite a lot together with  0.5 window type in my study. I am planning to replace that with a 1hp interter soon. The other bedrooms have 0.5hp window/wall types but they are rarely used.

Our total electricity is usually around P7000
Title: Re: Passive Cooling
Post by: medic3500 on May 16, 2014, 11:09:43 AM
Yikes, your electric bill alone is more than my rent and all utilities. I guess I'm a cheap ass.
Title: Re: Passive Cooling
Post by: Lee2 on May 16, 2014, 09:21:36 PM
I wish I had bought inverter units when we bought our two carrier units years ago but I do not think they were available back then. When they go, I hope no time soon, as they are expensive to buy new ones, then they will be probably replaced with inverter units.

Our units are split units, if I had it to do again then I might have bought window units as the noise helps cover outside noises and even I can work on window units to pull them out and clean them myself.
Title: Re: Passive Cooling
Post by: paulgee on May 17, 2014, 02:39:36 AM
Our house is a standard sub division property - hollow blocks and no roof insulation.

We can do nothing about the walls but if we stay there long term in future we will get some roof insulation.

During the 3 months we were there last year we used aircon but as frugally as possible and I think the cost would be manageable, especially as we have split aircon which is cheaper to use though more expensive to buy. And the Sep-Dec time we spent there was not the hottest time of the year, so that would have to be taken into account.

Paul

Yes, the aircon I referred to above are actually inverter types, Panasonic. Well worth the extra outlay, and cost us nothing to run whilst we live in the UK ! But obviously the maintenance is more than the standard aircon units.
Title: Re: Passive Cooling
Post by: Gray Wolf on May 17, 2014, 03:54:01 AM
I had to do a little research to find out what exactly an inverter type A/C is.  For those who, like myself, didn't know, here's the info:

"An inverter in an air conditioner is used to control the speed of the compressor motor to drive variable refrigerant flow in an air conditioning system to regulate the conditioned-space temperature. By contrast, traditional air conditioners regulate temperature by using a compressor that is periodically either working at maximum capacity or switched off entirely. Inverter-equipped air conditioners have a variable-frequency drive that incorporates an adjustable electrical inverter to control the speed of the motor and thus the compressor and cooling output.

The variable-frequency drive uses a rectifier to convert the incoming alternating current (AC) to direct current (DC) and then uses pulse-width modulation in an electrical inverter to produce AC of a desired frequency. The variable frequency AC drives a brushless motor or an induction motor. As the speed of an induction motor is proportional to the frequency of the AC, the compressor can now run at different speeds.[citation needed] A microcontroller can then sample the current ambient air temperature and adjust the speed of the compressor appropriately. The additional electronics and system hardware adds cost to the equipment installation but can result in substantial savings in operating costs.

Eliminating stop-start cycles increases efficiency"


Sounds like a good system!  :)
Title: Re: Passive Cooling
Post by: BingColin on May 17, 2014, 10:26:31 AM
Our large Samsung side-by-side fridge freezer is also an inverter type which should also help reduce electricity costs.

Dan, our neighbour opposite has a bungalow the same volume as our house and his electricity bill is only P2000. He has a large open plan living area that we found uncomfortably hot.
Title: Re: Passive Cooling
Post by: wildbill on May 17, 2014, 11:01:13 AM
Yikes, your electric bill alone is more than my rent and all utilities. I guess I'm a cheap ass.
Medic your no cheap ass,I also don't like high Bills ,we run one window unit during the niter then during the heat of the day,our bill runs about 2,to 3 thousand a month,..to each his own,but I'm not wasting the money.we must save for those Rainy days.
Title: Re: Passive Cooling
Post by: brett4gam on May 17, 2014, 01:04:04 PM
Hi Colin, I tried to use the quote button to make my post from your comment but for some reason it took the quote from rayhigh as well, so I did a copy and paste.

"Hi Ray, I would recommend that you consider 'Inverter' aircons, they are cheaper to run. I think they are only made in the split type which are a lot quieter that the window/wall type anyway. We favour the Samsung aircons, and other things, they are very good and less expensive than some other brands."

I agree the inverter is the only way to go, we have just purchased an LG 2.5 hp  split inverter system for the place we are renting here and will take it to the new house when we get it sorted out.  The opressive heat during the day and night got too much for us.

As part of research, I also wasn't aware of the window type air con that were an inverter type until I saw the ad from SM Appliances.  Mind you when I saw the price it was out of the question, can get a split type cheaper than what they advertised.

Thanks also to GW for doing the research and explaining the difference  :D

Cheers
Brett.
Title: Re: Passive Cooling
Post by: BingColin on May 17, 2014, 01:49:19 PM
Hi Colin, I tried to use the quote button to make my post from your comment but for some reason it took the quote from rayhigh as well, so I did a copy and paste.

"Hi Ray, I would recommend that you consider 'Inverter' aircons, they are cheaper to run. I think they are only made in the split type which are a lot quieter that the window/wall type anyway. We favour the Samsung aircons, and other things, they are very good and less expensive than some other brands."

I agree the inverter is the only way to go, we have just purchased an LG 2.5 hp  split inverter system for the place we are renting here and will take it to the new house when we get it sorted out.  The opressive heat during the day and night got too much for us.

As part of research, I also wasn't aware of the window type air con that were an inverter type until I saw the ad from SM Appliances.  Mind you when I saw the price it was out of the question, can get a split type cheaper than what they advertised.

Thanks also to GW for doing the research and explaining the difference  :D

Cheers
Brett.

I wasn't aware of a window type inverter either, but the split type are so much quieter with the compressor outside the house.
Title: Re: Passive Cooling
Post by: Gray Wolf on May 19, 2014, 01:26:56 AM
Hi Colin, I tried to use the quote button to make my post from your comment but for some reason it took the quote from rayhigh as well, so I did a copy and paste.

Thanks also to GW for doing the research and explaining the difference  :D

Cheers
Brett.


Brett and all,

This might help explain how to use the quote function:

http://www.livinginthephilippines.com/forum/index.php?topic=49082.new#new (http://www.livinginthephilippines.com/forum/index.php?topic=49082.new#new)

You are quite welcome!   :)
Title: Re: Passive Cooling
Post by: arlie on May 19, 2014, 05:30:20 AM
Brett or any one else who knows the answer and would like to tell me.  My understanding of the split type air con is that the compressor is located in a different place from the evaporator and the two are connected by copper tubing carrying refrigerant.  At least here in the states after those two are connected the system which was shipped separate must be vacuum pumped and refilled with refrigerant.  How can they be moved from place to place in the Philippines with out a technician with the right equipment to hook them back up? I ask because I would like to purchase a split unit for our house there but don't know where to find a technician.      Thanks for any help.   Arlie
Title: Re: Passive Cooling
Post by: Lee2 on May 19, 2014, 06:30:25 AM
Brett or any one else who knows the answer and would like to tell me.  My understanding of the split type air con is that the compressor is located in a different place from the evaporator and the two are connected by copper tubing carrying refrigerant.  At least here in the states after those two are connected the system which was shipped separate must be vacuum pumped and refilled with refrigerant.  How can they be moved from place to place in the Philippines with out a technician with the right equipment to hook them back up? I ask because I would like to purchase a split unit for our house there but don't know where to find a technician.      Thanks for any help.   Arlie

The places you buy split units from have installers come out and install them. We bought two split Carriers and the place we bought them from installed them.
Title: Re: Passive Cooling
Post by: brett4gam on May 19, 2014, 09:42:39 AM
Brett or any one else who knows the answer and would like to tell me.  My understanding of the split type air con is that the compressor is located in a different place from the evaporator and the two are connected by copper tubing carrying refrigerant.  At least here in the states after those two are connected the system which was shipped separate must be vacuum pumped and refilled with refrigerant.  How can they be moved from place to place in the Philippines with out a technician with the right equipment to hook them back up? I ask because I would like to purchase a split unit for our house there but don't know where to find a technician.      Thanks for any help.   Arlie

Hi Arlie, Lee is correct, you can normally arrange an installer from the retailer, so far, after buying a few units from various places we found that if you do not use their installer, they claim it voids the warranty.  This is yet to be seen as so far we haven't run into any problems, and have registered each unit with the manufacturer for warranty.

In the typical extended family we have an electrician who does the electrical connection for a qualified Air con technician who has all the equipment required.  The unit we purchased last week was installed perfectly by the technician, and he will be the one we will use when it comes time to relocate it.

I think from memory the refrigerant has to be captured, the unit moved, vacuum pumped again and new refrigerant installed.

Hopefully a painless task, but it is some time off yet.

Tks GW for the helpful advice on using the quote button, worked this time, guess there may have been a temporary glitch the other day when I tried to use it, or I just buggered it up.  ;D

Cheers
Brett.
Title: Re: Passive Cooling
Post by: arlie on May 19, 2014, 09:49:00 AM
Brett and Lee.  Thank you very much for your quick reply.  That eases my mind considerably, I will get one on my next trip to the Philippines.  Arlie :)
Title: Re: Passive Cooling
Post by: Gray Wolf on May 20, 2014, 05:31:04 AM

Tks GW for the helpful advice on using the quote button, worked this time, guess there may have been a temporary glitch the other day when I tried to use it, or I just buggered it up.  ;D

Cheers
Brett.

Walang problema, brod!  I know it's sometimes a daunting task making these forums work the way we want.  It took me quite some time to figure out what little I do know.   ;D  :)
Title: Re: Passive Cooling
Post by: Colin on March 15, 2019, 05:50:49 PM
I have been away for a few days visiting El Nido so have not been able to respond until now.

I think it important to insulate walls even if you are not planning to use much aircon. Take a look at this section of my web site. [url]http://thephilippinejournal.wetpaint.com/page/Design[/url] ([url]http://thephilippinejournal.wetpaint.com/page/Design[/url])  We use very little aircon and the house is noticeably cooler most of the time even with the windows open. A hollow block wall has an R value of around 1.0 and my 3 inch polystyrene walls around 11.0. That is 11 times better; they are cold even if the sun is on them all day. If you want to use aircon then you will have a big reduction in electricity bills. We only have fans in the lounge and master bedroom, but I do use a small aircon more often in my study. There are other aspects of house design that you need to consider to make it comfortable, and I cover them on my web site.

Whatever you do with the walls, it is essential to insulate the attic space and give lots of ventilation. We used 6 inch foil bags filled with fibreglass from Citi Hardware, but they then stopped stocking it at our local store. You should be able to buy the rolls of fibreglass at building supply stores.

This is an old 'lost' post of mine, but I though I should update the website address anyway. It is http://thephilippinejournal.wikifoundry.com/page/Design. (http://thephilippinejournal.wikifoundry.com/page/Design.)
Title: Re: Passive Cooling
Post by: JoeLP on March 15, 2019, 08:57:18 PM
I'm from Michigan in the USA originally.  We go yearly from weeks rarely above freezing to weeks in August rarely with a high below 85-90 degrees.  My dad made his money in the construction industry and mainly in residential homes.  His company grew a big name in one of the more rural areas in the UP of Michigan.  How'd he do it?  His houses were very well know for their insulation. 

The better you insulate, the better money you save.  We have a split system in our house now for a couple years and I had to fight with Tina to get her to understand what we NEEDED to do before hand.  She went ahead and bought the spit system anyway.  This was for the upper level(all of it) and our staircase was open going to the lower and our outer walls we only finished.  No paint or insulation(and the outside wasn't even complete finished at that time).  She hooked it up and we only used it part time and our bill went up over 5000php/mo.  Got the stairs enclosed.  The excess costs in the electric bill went down to only a 3500 jump.  Had half of the outer finishing that was finished hammered off, then went with the foam fiber cement mix and had it all finished.  Then flexicoat painted.  We now only have a bump in our electric bill of about 1500-2000.  Oh, and we use the AC all the time and it keeps the complete upper level(2 beds and a living area) completely cool at a much more effective level.

Insulation, in the big picture, saves you MUCH more money and electric if you do it right.
My dad built a lady a home just outside of Munising, MI in the UP.  She was living in it for her first winter.  A brutally cold one.  Her first gas(heating) bill came and it was really low.  Her new house was bigger than her old one, and the bill under half what her old house was.  She called the gas company and demanded they check into it.  She was afraid they'd find the mistake later and need to pay a huge fee then.  They came and checked everything out, and found nothing wrong.  She called again after the next month's bill came and same thing, it was too small.  This time when she called the gas company's call center the man finally asked "who built your home".  She said H & H Construction.  The man told her she had nothing to worry about.  That the company that built her house is why it's so cheap and that her house is just very well insulated.  That's what built my dad's business to being so large was his reputation on being able to give so many layers of insulation yet not jump the price but a little.  I grew up in the homes he built/remodeled.  I learned first hand the money saved if you insulate properly. 

All that said, if your renting, or not looking to stay in your house very long, it's not worth the investment.  Even more so in a place like the Philippines where the average person doesn't think about such things and such things are very unlikely to raise the value of your home because of such.

Also, like others have said on here, the place you buy your split system from has installers and our required that we use them for warranty sake.  And we have used that warranty 2 times.  Nothing the fault of the AC unit(and LG) but rather the workers who worked on it.  The local Robinson's appliance was unsure what to do because Tina and I were the first to get out the warranty and demand they live up to it and get someone to fix it.  No one ever demanded they live up to the warranty.  Sorta funny to me.  But, they did it(after a call to LG from Tina and myself) and at no cost to Tina and myself, they fixed their mistake.  But, the warranty was void if an unlicensed tech installed it.  So we just allowed their installers to do it all.  Think it cost like 800php.  Worth taking that route.