I've heard of Thermalite paint many times in my years on these Q&A forums, and basically it's widely agreed that Thermalite, Hy-Tech Sales, Insul-Add, and what ever other name the company is now using, is a scam. Basically, the only difference between Thermalite paint and ordinary latex or oil based paint is that Thermalite paint contains tiny hollow ceramic microspheres. The void inside the microsphere is supposed to be a vaccuum, and the idea is that the tiny microspheres act like a multitude of miniature thermos bottles that prevent heat transfer through the paint. This, at least, is how the product works according to this Hy-Tech Sales web page:
Insulating Paint Additive Makes Paint Insulate
While it's true that a vaccuum insulates well, heat will travel through the ceramic shell of the microspheres, and then the small distance it has to travel to get from one side of the paint film to the other greatly limits the effectiveness of this paint.
Here's a dialogue between a Hy-Tech Sales franchisee and a "crusader" who was apparantly quite familiar with the product and wanted to take on the claims of Hy-Tech Sales. Read it and make up your own mind:
Epinions.com - Comments on 'Insuladd, Thermilate & Hy-Tech Sales Paint Additives: Grossly Exaggerate Energy Saving Potential'
And finally, Hy-Tech Sales claims that the product was developed by NASA, and I have no doubt that it was. However, NASA develops lots of new ideas, some of which have tremendous commercial value (such as the cordless drill) and others that very well COULD have tremendous commercial value once a commercial use for them is found.
As it stands now, the 3M company is developing ceramic microsphere technology:
3M is selling these microspheres to be used as extender pigments in paints and other coatings. The idea is that because the microspheres are very hard, they increase scrub resistance in a paint so that you can scrub the paint very hard without leaving a dull mark. And how the microspheres do that is simple to explain. Imagine you scrubbed the BACK side of a piece of sandpaper with your hand or a cleaning tool like a Magic Eraser. It wouldn't be long before you damaged that backing paper. Now imagine doing the same thing on the front side of that piece of sandpaper. The hard abrasives on the front of the sandpaper would stand up much better to that scrubbing and would protect the paper. In the same way, having hard particles in a paint film helps protect the paint film from being scrubbed off by hard scrubbing, and by using hard particles that are small enough, they can also help the paint keep it's gloss level in spite of being scrubbed very hard.
But, apart from everything everyone else says for or against this paint, just look at it this way:
We Canadians and the Americans living south of us are spending billions of dollars every year heating our homes in winter and air conditioning them in summer. And, both of our governments take it upon themselves to encourage energy conservation through a variety of programs, like rebate programs (typically run by our local utilities) that refund part of the purchase price or through tax incentive programs. If significant energy savings could be had by using this insulating paint additive, then:
a) why wouldn't the tree-huggers be endorsing it as a way to help save the planet?
b) why wouldn't the US Government be endorsing it as a way to help break America's addiction to mid-East oil?
c) why wouldn't every other US paint company be making and marketing an insulating paint? After all, if NASA developed the technology at US tax payer's expense, then the patent rights on the technology are owned by the American public, and would be free for any American to use as they wished, just like cordless drill technology.
and d) why wouldn't a reputable company like 3M be advertising the energy conservation benefits of adding it's microspheres to paint. Do you think that no one has ever brought Thermalite paint to the attention of the engineers and scientists working at 3M?
Don't get me wrong. I put ceramic microspheres in the same bag as laser beams were 50 years ago. There WILL be numerous uses for this technology, most obviously in nanomachines, conventional lubricants, or in medicine as a way of delivering controlled doses of drugs over extended periods of time (such as pain killers). But, the future of microspheres is coming, it's not here now, and it certainly isn't as a scam to separate hard working people from their hard earned money.