Steve: If your spray foam installer leaves the vents open, he will be committing the 2nd of the 4 problems I described above. You will most likely have comfort and efficiency problems. You may well have condensation problems. You will be spending a lot of money on a product that likely won't perform as it should. Don't let him leave the vents open. If the installer you've chosen doesn't understand this, you may want to choose someone else. 
Whether you work on frame-up restorations in your garage, or projects like refinishing wheels, interior upgrades or maintaining the appearance of your everyday ride, Dupli-Color wants to be there with you. We have a heritage of providing only the best in automotive products since 1938, when we first started selling touch-up paint. This marked the beginning of “innovative firsts” which continues today with the automotive aftermarket’s largest array of DIY paints, primers and coatings. Spray Coating Services
These operate connected to a high pressure pump commonly found using 300 to 7,500 pounds per square inch (2,100–51,700 kPa) pressure to atomize the coating, using different tip sizes to achieve desired atomization and spray pattern size. This type of system is used by contract painters to paint heavy duty industrial, chemical and marine coatings and linings. Coating Services

Like HVLP, low volume low pressure (LVLP) spray guns also operate at a lower pressure (LP), but they use a low volume (LV) of air when compared to conventional and HVLP equipment. This is a further effort at increasing the transfer efficiency (amount of coating that ends up on the target surface) of spray guns, while decreasing the amount of compressed air consumption.
“Since most of mechanical heat is IR heat, ceramic coatings can be used to prevent heat loss from inside a building,” Pritchett says. A home interior coated in ceramic paint can therefore reduce energy costs due to heat loss in the colder months. “We estimate that a home can save up to 40 to 50 percent in energy costs using our product,” Pritchett says. Payback on a product like SuperTherm, which retails for about $100 per gallon, can come in as little as two years.
In cold spraying, particles are accelerated to very high speeds by the carrier gas forced through a converging–diverging de Laval type nozzle. Upon impact, solid particles with sufficient kinetic energy deform plastically and bond mechanically to the substrate to form a coating. The critical velocity needed to form bonding depends on the material's properties, powder size and temperature. Metals, polymers, ceramics, composite materials and nanocrystalline powders can be deposited using cold spraying.[4] Soft metals such as Cu and Al are best suited for cold spraying, but coating of other materials (W, Ta, Ti, MCrAlY, WC–Co, etc.) by cold spraying has been reported.[1]
Yes, absolutely. If you put spray foam insulation in a building, it needs a thermal barrier. That's what separates it from the occupied spaces. If there's a fire in the building, a thermal barrier keeps the combustible spray foam from the flames to increase fire resistance. The International Residential Code (IRC) and Internation Building Code (IBC) both include requirements for thermal barriers (and ignition barriers, too; see below).

The atomization of molten materials produces a large amount of dust and fumes made up of very fine particles (ca. 80–95% of the particles by number <100 nm).[8] Proper extraction facilities are vital, not only for personal safety, but to minimize entrapment of re-frozen particles in the sprayed coatings. The use of respirators, fitted with suitable filters, is strongly recommended, where equipment cannot be isolated.[8] Certain materials offer specific known hazards:[6]
Sean, thanks for jumping in and answering John's questions. About choosing the right foam, I intentionally avoided the open cell vs. closed cell foam debate. I did this partly because it's worthy of an article all by itself, but mainly I didn't include it because, despite all the warnings the two sides issue about the other, I've never personally seen a problem caused by using open cell where they should've used closed cell or vice versa. I'm sure things like that happen; I just haven't seen it yet.

4 years ago I applied Gaco Roof, coats to an Office Building flat roof and have zero leaks since that time. This saved me $30,000 compared to having a new roof installed. The roof itself was only 7 years old when I applied Gaco Roof. but due to ponding water and harsh Florida heat and UV, the roof already looked shot and was leaking. I have now used Gaco Roof on 4 flat roofs to great results. I also tried big hardware store lower cost substitutes on 2 flat roofs. Those product utterly failed 1 to 2 years. Yes, I pressure washed my roofs clean before using Gaco Roof and followed their simple installation instructions. Excellent product. Insulation Spray Coating

I applied the Gaco 100% Silicone Roof coating to a slightly-sloped, metal porch roof.  My leaks have stopped, and it looks like they are gone for good.  I followed the instructions, and it appears the product made a perfect bond to the roof.  What a terrific product!  I'm glad I made this purchase, and that I didn't settle for a cheap, metal coating from the local outlet store. Spray Coating

The average price to cover 200 square feet with a foam insulation kit will run between $300 and $600 (about two to three kits). Inside these kits is something called Icynene, a foam made from two liquids that are heated and pushed through a gun on the can. When Icynene is released, it expands up to 100 times its size as it hits the surface area you're covering. These can contain a lot of gasses, making its installation a dangerous process. Even low-pressure sprayers can be harmful to homeowners' health.

For over a decade, Synavax™ has served as the preferred industrial thermal barrier insulation, energy saving, surface protection and asset protection coating, meeting the needs of multiple industries around the world, including pulp and paper manufacturing, food and beverage manufacturing, U.S. military, oil and gas, textile manufacturing and many others. Spray Coating