You guys do know that use of on-location heat units could set you up for a lawsuit? Even if you're not killing bugs ThermaPure may tell you that you're infringing on their patent and have to pay them to use the equipment you already own. Many in the industry feel that ThermaPure got a patent for something that was already in common use, making their demands for payment "patent trolling." Patent trolling is when a company uses a questionable patent to sue companies into paying royalties to avoid incurring the cost of a lawsuit.
Water Out has gone bankrupt, and TP is taking individual cleaning and restoration firms to court if they don't pay. Some of the big boys in the industry have gone to court with ThermaPure to avoid paying royalties (and one little guy racked up over 300k in legal expenses rather than pay TP) but none has gone far enough to invalidate the TP patent.
You have choices: Keep your head down and your "heat" services quiet; Pay TP; Spend hundreds of thousands of dollars on legal fees; Go out of business.
Or, contribute to a legal fund to invalidate the patent.
http://restorationindustry.org is managing the Restoration Industry Legal Fund and this is their current cause.
If you do business in California, Ed Cross has an angle that might keep TP from collecting fees there. He's asking for contributions to the Restoration Industry Defense Alliance.
http://www.restorationdefense.org