Thermal results for skoolie surfaces, paint, insulation

[Rusty]

It is 80 degrees air temp when I took these samples using a very expensive HF tool: Infrared Thermometer Non-contact, Digital ($15). Test was done very scientifically and tester was sober. It's Sept 23 in Chicago and our high temp today is going to be 91 degrees (record) .

First post will be exterior temps, 2nd post will have interior measurements.



Driveway, shade temp




Driveway sun




Tire in sun




Blue paint in sun





White paint in sun





Reason I'm fooling around with this as it's too hot to paint nose of bus must wait a bit- paint can says not to apply above 93 degrees surface temp.

Something something Global hotness.

[Rusty]

Here are the interior temps:


Foam wall, inside, wall facing sun




Rib, inside, wall facing sun




FRP ceiling w/ foam




White emergency door, inside, facing sun




Tinted glass,




Single pane clear glass, inside facing sun

[PNW_Steve]

Rusty,

was it you who did the side by side of different roof paints and measured temp differences a while back?

[EastCoastCB]

I think that was Jazty.

Your results look just like what SuperDave and I found.
The flat white on his roof was more than ten degrees cooler than the blue on the sides. The flat white was double digits cooler than any other color or surface on the entire bus.

[Rusty]

Originally Posted by PNW_Steve

Rusty,

was it you who did the side by side of different roof paints and measured temp differences a while back?

Not I. Is eye-opening, though. Tinted glass was HIGHER???

[EastCoastCB]

Originally Posted by Rusty

Not I. Is eye-opening, though. Tinted glass was HIGHER???

Dark colors absorb heat.

[Rusty]

Originally Posted by EastCoastCB

Dark colors absorb heat.

ya think??

[Serengeti]

Originally Posted by Rusty

ya think??

Thanks for sharing. Looks like I will be buying 5 gallons of white paint.

Sent from my SM-G955U using Tapatalk

[cadillackid]

also remember NOW.. as in late september is *NOT* the time to be sun testing up north.. our sun angle is not nearly what it is in the summer solstice... .. and yes surfaces are still going to be hotter or cooler based on color.. if you really want to know what repels and what aborbs heat.. wait till mid may through late july next year... or go to florida.. the sun angle in florida right now is similar to what it is in chicago in july..
-Christopher

[family wagon]

Also remember the physics involved in the IR thermometer. A few common misconceptions:

• the laser doesn't have anything to do with the temperature measurement. It's just a laser pointer to help with aiming.
• the measurement area is a circle, not a tiny point. It's the base of a cone whose peak is at the thermometer device. As distance between the device and the measured surface increases, the measurement area increases too. ("distance-to-spot ratio")
• emissivity matters. Per wikipedia: "Most surfaces have high emissivity (over 0.9 for most biological surfaces), and most IR thermometers rely on this simplifying assumption; however, reflective surfaces have lower emissivity than non-reflective surfaces. Some sensors have an adjustable emissivity setting, which can be set to measure the temperature of reflective and non-reflective surfaces. A non-adjustable thermometer may be used to measure the temperature of a reflective surface by applying a non-reflective paint or tape, with some loss of accuracy."

The last point may explain some of the surprise in the glass temperature measurements.

[PNW_Steve]

Originally Posted by family wagon

Also remember the physics involved in the IR thermometer. A few common misconceptions:

• the laser doesn't have anything to do with the temperature measurement. It's just a laser pointer to help with aiming.
• the measurement area is a circle, not a tiny point. It's the base of a cone whose peak is at the thermometer device. As distance between the device and the measured surface increases, the measurement area increases too. ("distance-to-spot ratio")
• emissivity matters. Per wikipedia: "Most surfaces have high emissivity (over 0.9 for most biological surfaces), and most IR thermometers rely on this simplifying assumption; however, reflective surfaces have lower emissivity than non-reflective surfaces. Some sensors have an adjustable emissivity setting, which can be set to measure the temperature of reflective and non-reflective surfaces. A non-adjustable thermometer may be used to measure the temperature of a reflective surface by applying a non-reflective paint or tape, with some loss of accuracy."

The last point may explain some of the surprise in the glass temperature measurements.

You Sir are a wealth of knowledge! Thank you for your contributions!!

[family wagon]

Whoa there, that's maybe overdoing it a bit!

In this case I read the business card sized user guide that came with my own $15 IR thermometer a year ago and today remembered just enough of it to be able to search online and refresh my memory of the relevant buzzwords.

This thread reminds me: I always thought it would be interesting to take a thermal camera into a stock bus and have a look, especially in the summertime. This year I bought another bus, and in the hottest July on record for Salt Lake City no less. But I didn't even think of the thermal camera until I saw this thread today. We're supposed to warm back up to mid-70's here by the end of the week. As cadillackid points out the angle of the sun just isn't the same now as it was in July, but maybe it'll still be interesting.

[cadillackid]

I always hate that about IR thermometers becuase when im working on HVAC it would be so nice if I could measure the pipe temperatures with one.. but of course I learned early on thats very inaccurate.. dull mat surfaces they seem to do pretty good with... even flat light colored painted surfaces.. just not much reflectivity or they are inaccurate.
-Christopher

[Rusty]

Originally Posted by family wagon

Some sensors have an adjustable emissivity setting, which can be set to measure the temperature of reflective and non-reflective surfaces.

The last point may explain some of the surprise in the glass temperature measurements.

I don't think my $15 Harbor Freight tool accounts for emissivity. Makes sense because my hand disagreed with the #s.

This got me wondering while I was working inside the bus. I had my hand on the wall (foam), then moved forward and my hand was on a rib and it felt HOT. It felt like someone had a torch on it. Seems like the ribs focus the big sheet panel heat to a point of ingress.

I can't wait for the Harbor Freight FLIR camera. Have seen the smartphone ones- way nifty.

> Cadillac: I tried to tilt the Earth, but no go. I guess I'll have to drive down to Florida for retest (and help you guys party) this weekend!

[cadillackid]

Originally Posted by Rusty

I don't think my $15 Harbor Freight tool accounts for emissivity. Makes sense because my hand disagreed with the #s.

This got me wondering while I was working inside the bus. I had my hand on the wall (foam), then moved forward and my hand was on a rib and it felt HOT. It felt like someone had a torch on it. Seems like the ribs focus the big sheet panel heat to a point of ingress.

I can't wait for the Harbor Freight FLIR camera. Have seen the smartphone ones- way nifty.

> Cadillac: I tried to tilt the Earth, but no go. I guess I'll have to drive down to Florida for retest (and help you guys party) this weekend!

ha!! i wish the tilt mechanism would fry and lock with ohio stuck in Summer mode... alas yeah!! be great to meet ya!! and hey sounds like there will be a few other busses down there so while likely no sceni-cruisers or silver-sides still you can hang with some cool bus-folk!!

remains to be seen which bus I drive down.. I knew i shoulda just torew that hib apart on redbyrd myself instead of send it to a shop.. grrrr they are taking too long...
-Christopher