Window "tint" saves fuel through reduced AC load (duh, but nice to see quantified)

[NeilBlanchard]

Hi,

This isn't just any tinting -- it is low-E coating that blocks infrared light (heat). The "tinting" may not even be visible to us...

[Clev]

Originally Posted by NeilBlanchard

Hi,

This isn't just any tinting -- it is low-E coating that blocks infrared light (heat). The "tinting" may not even be visible to us...

From experience, the only way the stick-on tint lowers temperatures is by forming an air barrier as it starts to peel off the glass.

[Piwoslaw]

Originally Posted by QuickLTD

Am I wrong? Since most automotive A/C units are not temperature based systems like home units, once its on... it is on. Same engine load wherever the knobs are turned. Max AC just moves a baffle recirculating cabin air and the temperature control knob also just controls the mix between the a/c cooled air, air in the heater box and or outside/cabin air. Climate controlled cars like mine work on the same principles except the computer controls the mixtures. None of this should have anything to do with the compressor cycling. Turn on your a/c in 30deg F weather and see what I mean. It still turns on and cycles regardless.

The only thing I could see the tint doing is making it stay cooler longer if you wish to manually switch the a/c on and off every 5 minutes or making it cooler in general so you dont need a/c

If I am incorrect as to the operation of automotive A/C please correct me.

Dean

This was true in older A/C units, but newer ones cycle on and off depending on inside temperature. My Peugeot has something called Klimatronic, you can independantly set a different temp for the driver and passenger, and when driving I can feel the load suddenly increase when the compressor turns on.

[blueflame]

Same for white cars improving FE. Coupes with little glass cooler.

Houses still get made without thermal design, too.

Corrugated iron roofing seems to rust quicker when its painted dark red

A sun shade for the whole vehicle cab would be cool

The cops in NZ didnt like not being able to see inside vehicles so dark tints are out now.

[botsapper]

It's true that the high performance 'tints' should offer (low-e) lower emmisivity properties, reflecting thermal radiation back out while still having good transparency qualities. There were studies with 'smart glass', active darkening glass, but law enforcement precludes this for their observation duties & their safety. Other safety aspects are the slightly better UV protection from melanoma & interior upholstery deterioration and the additional glass integrity it provides in breakages since manufs. are using lighter & thinner panes.

[DonR]

Sort of related.

My Jeep's black hardtop has no headliner. I am going to make one, l really for insulation, this summer when I can take it off. I was planning on using a spray adhesive to attach a layer of aluminum foil to the top (roof side) of the backer. Shiny side up. The hope is that it will help with it getting hot in the summer & slightly warmer in winter.

It could easily be done on an existing headliner.

Don

[wagonman76]

"The adjusted, utility factor-weighted fuel economy increased from 36.8 to 42.9 mpg"

Seems overestimated to me. 16.5% FE increase from tint is ridiculous.

I agree. When I run my AC it makes no difference in FE numbers. For cars more efficient to start with it would make some difference in numbers. But 16.5%, no way, except maybe for Bassjoos.

[Clev]

Originally Posted by Piwoslaw

This was true in older A/C units, but newer ones cycle on and off depending on inside temperature. My Peugeot has something called Klimatronic, you can independantly set a different temp for the driver and passenger, and when driving I can feel the load suddenly increase when the compressor turns on.

I just Pulse 'n' Glide mine.

[NiHaoMike]

I read somewhere that the Prius already uses a window coating to reflect infrared. (Which means that solar panels to top off the battery are less effective.)

[MetroMPG]

Anybody figure out which car they used in the study? I did a little digging on their site, but didn't find details.