Aside all the scientific arguments and counter argument the fact remains that Insulation on an open carport makes litle difference in the temperature of the car, parked underneath it. 

Does it make any difference, I am sure it does, but is it significant enough to care? I don't think so,

If I was making a carport and insulation was inexpensive enough I would use it , but if it made a significant impact on the price, I would not. 

1 hour ago, Thian said:

So what's the best roofing material for a stainless steel carport these days?

If you actually have a Stainless Steel 18-8 roof that is buffed then it’s Emissivity is at about 0.16, (aluminium foil is at about 0.095) the problem with stainless steel is that the Oxidized surface is at about 0.83 so buffed its good but if it oxidises it is quite bad

 

for reference 1 is a perfect emitter (the perfect black body), the closer you can get to 0 the worse an emitter a surface is so the more you like it

36 minutes ago, sometimewoodworker said:

The company is in Khon Kaen I talked to them at an architectural show there, maybe a year or two ago. So if you are within about 100km of KK I will look up the information when I get back home and can send it by PM 

No i'm in BKK and want it from here, from a large company like thaiwatsadu or homepro or so.

8 minutes ago, sometimewoodworker said:

If you actually have a Stainless Steel 18-8 roof that is buffed then it’s Emissivity is at about 0.16, (aluminium foil is at about 0.095) the problem with stainless steel is that the Oxidized surface is at about 0.83 so buffed its good but if it oxidises it is quite bad

 

for reference 1 is a perfect emitter (the perfect black body), the closer you can get to 0 the worse an emitter a surface is so the more you like it

No only the frame is stainless steel...so the roof can't be so heavy.

 

But the plastic sheets are a little translucent and black....it's really hot underneath and that heat also blows into the kitchen/house......so i want a high quality insulated panel which can be curved and lasts at least 10 years. 20 years would be better though.

24 minutes ago, Denim said:

If , however , that area is sometimes used to sit under then the difference might be worth it to some people but frankly I would say not worth the money since a slight breeze negates any small difference.

The reason for adding the silver foil Under my roof was precisely the fact that I could not go outside when the sun was on the roof because my head was uncomfortable due to the heat radiating from the underside of the roof. Any breeze was irrelevant as it had little effect on the radiant heat.

5 minutes ago, Thian said:

No only the frame is stainless steel...so the roof can't be so heavy.

 

But the plastic sheets are a little translucent and black....it's really hot underneath and that heat also blows into the kitchen/house......so i want a high quality insulated panel which can be curved and lasts at least 10 years. 20 years would be better though.

I suggest taking the pictures from this thread with you and going into specialist roofing shops.
 

I do have the contact information for one of the formers of Colorbond profiles. They will certainly be able to curve the material, they also offer a foam insulation with a silver surface. I am not sure that they would deal direct for such a small order but I’m sure they would put you in touch with a retailer that they supply they are in SamutPrakan.

They are similar to the company that supplied and fitted our roof, in fact one of the directors moved to them.

 

 

17 hours ago, sometimewoodworker said:

Claiming or stating your work history and Experience does not prove your point.
 

Stating that a black body is an excellent radiator of heat (a fact that I haven’t disputed) does not make your point.

 

Bringing in convection and conduction a methods of heat transfer certainly does not make your point.

you said, please address your incorrect statement. 

You seem to have this mindset if you can prove me wrong on black body radiation, everything else I say will have no credibility. Sorry, you can’t prove a negative. My post meant to say a black body is the most efficient vehicle for distribution of radiation. Of course other surfaces distribute radiation too, at different efficiencies. Go argue with a physics textbook, not me.

 

Two photos are attached. The first is a carport, with unlined cement sheet roofing. No insulation, no reflective foil. Photo taken at 8 am, for best lighting. The air gap between the roof of the car and the apex of the carport roof is about 2 metres.

 

The second photo is the car’s instrument display, which according to the car manual measures the car’s external temperature, presumably through a thermocouple. 29 C. After four hours or more of direct sunshine. That tends to make nonsense of your toastie 60 C radiation heat transfer. Convection is taking care of it.

 

One of the central tenets of science is the repeatability of any experiment. If it is done independently, as I have done, and another poster has done, that establishes the credibility of the data. Your problem is you are collecting data and interpreting it incorrectly. I’m quite sure if I used your instrument, I would get the same data as you do.

 

I do find it a bit amusing when posters are discussing options of insulation and reflective foil. It’s a freaking carport, right? It’s not a house. Is KISS ( Keep It Simple, Stupid ) part of your skillset?

 

I’ve noted another poster has called for politeness and courtesy in disagreeing over a thread. You do make that somewhat difficult. Go back to your post #16 if you disagree.

 

I can explain it to you. I can’t understand it for you.

 

1 hour ago, Lacessit said:

You seem to have this mindset if you can prove me wrong on black body radiation, everything else I say will have no credibility

There as it seems you are once again implying something I have never done. 

 

The only statements of yours I have questioned are on radiation (and your misstated assertion of mine of temperature at the car roof, do read what has been written by me)

 

you have twisted my correction of your incorrect statement on radiation to imply that I am saying things about other factors, I am not, in relation to your posts I haven’t talked about anything but Emissivity, while you seem intent on talking about anything but Emissivity

 

you have not corrected your assertion that “unless the underside is black very little radiation transfer will be occurring“
 

A black underside will have an index of around 0.9xx (possibly 0.999) depending on the exact coating. 
aluminium foil 0.02~0.05, most other colours will be about 0.95 (or very close to that of black and very far from aluminium)
 

References:

1) Handbook of Chemistry and Physics, Chemical Rubber Publishing Co., Cleveland, Ohio

2) DMIC Report 177, Battelle Memorial Institute

3) Thermal Radiation Properties Survey, Honeywell Research Center

on the radiation/emissive characteristics of different Colours 

21 hours ago, Lacessit said:

Unless the underside is black, very little radiation transfer will be occurring. The main mechanism of heat transfer will be convection. Provided the carport is well ventilated, convection would not be an issue.

Why do you think builders install soffits and roof vents?

My carport is completely open on all four sides. Unlucky for me I got stuck with a sh#t product.

It appears that this issue has turned into a slinging match over the product at hand, this thread was raised purely to inform people about this type of insulation and the possible pitfalls one might encounter when purchasing without some prior research. 

why would you insulate the underside of a carport ? I have had one put up with no insulation, after 14 years it looks as good as new

31 minutes ago, soalbundy said:

why would you insulate the underside of a carport ? I have had one put up with no insulation, after 14 years it looks as good as new

Simple, from time to time I have a get together of friends and because my dining room has limited seating, I set up tables and chairs outside under my carport. The radiant heat is dramatically reduced.

We also like to do things under the carport but if it's bloody hot there we don't do it.

Plus our carport is connected to the house and that very hot air blows into the kitchen when the windows are open.

 

And if the kitchen is very hot the relay of the double door fridge starts clicking nonstop...(above 33 celcius)...because they sold me a double door fridge with icemaker and watertap which is not suited for thailand....bought it at Power Buy...it clicks every day for 10 years but still works good.

2 hours ago, DUNROAMIN said:

Simple, from time to time I have a get together of friends and because my dining room has limited seating, I set up tables and chairs outside under my carport. The radiant heat is dramatically reduced.

Have you thought of running a couple of fans to keep the air moving?

The crazy rude arguing that takes place in this forum, frequently involving the same people, makes me wonder why they are not removed by admins?  It really does become tiresome dealing with these people...
People are free to share differing opinions, but the lack of civility and general argumentatative comments (with a need to "win") from some are so childish it makes me wonder if at least one of these people isn't America's Toddler in Chief - the Great Orange One!  ????

On 10/30/2019 at 4:27 PM, sometimewoodworker said:

If you read what I posted you would understand that that was exactly what I said

 

Radiant heat is not ambient heat 

 

Ambient heat has a very loose relationship to radiated heat. Just stand in the shade of a tree at 7 am on a sunny morning now then step out into the sun.

Google thermal emissivity and IR temperature measurement. It has a huge effect on apparent temperature readings. But what would I know after twenty years of experience in the thermal imaging field in industrial plants.

Paint both of your targets matt black and then take a reading if you want any sort of accuracy. Doubt if the cheap IR thermometer you are using has the capability to adjust for thermal emissivity. The high quality gear from makers like Fluke do have but they are not really in the handyman's tool kit....or budget.

8 hours ago, emptypockets said:

Doubt if the cheap IR thermometer you are using has the capability to adjust for thermal emissivity.

It does thank you

Despite some glowing reviews  by others on "Colorbond"  I  found  the company useless, had a similar problem with damaged  panels, owner i bought from couldnt give a flying fart, colorbond  head office Thailand  never even replied to my e mails, So mailed Australia instead saying Thai colorbond dont respond and in STUPID passing the buck style they responded saying I should e mail the Thai colorbond  importer................Christ they are all w$nkers

On 11/1/2019 at 9:09 AM, JimShortz said:

The crazy rude arguing that takes place in this forum, frequently involving the same people, makes me wonder why they are not removed by admins?  It really does become tiresome dealing with these people...
People are free to share differing opinions, but the lack of civility and general argumentatative comments (with a need to "win") from some are so childish it makes me wonder if at least one of these people isn't America's Toddler in Chief - the Great Orange One!  ????

toughen  up