Here is the part most people never hear about. When a company says it offers heat treatment, that can mean several very different things, and it is easy to mistake one setup with another. The cheapest arrangement is electric heaters. These are the units a lot of companies run because they cost somewhere in the region of $25,000-$30,000, but a single one puts out only 36,000 to 70,000 BTUs while drawing close to the entire power supply of a home. They are slow, as well. Getting a home up to a killing temperature can take over two hours with electric, and a slow rise gives the bugs time to sense the change and work themselves deeper into the walls, where the heat may never reach them at all. Propane units are stronger. The direct-fired sort can reach 900,000 BTUs, but they burn their fuel right in your living space, putting off carbon dioxide and humidity as they go, and heat that concentrated has been known to melt fridge handles, warp vinyl floors, and char wood furniture. The indirect-fired sort is cleaner to breathe around but much weaker, roughly 80,000 BTUs a unit, so a home really needs eight or more of them, along with a long row of propane tanks, and most companies only show up with three.
The system we use is called Heat Assault, and it works on a different principle. It is a sealed 660,000 BTU boiler that heats a food-grade glycol – a fluid rather than a flame – and pumps it out to as many as nine heaters placed through the home. Because the fluid is held at a set temperature, somewhere between 205°F and 100°F depending on the size and insulation of the house, the heat that arrives in each room is even, and there is nothing burning inside your home while it runs. Most homes are past 120°F within the first half hour and can be brought toward 140°F inside the hour. At those temperatures, the heat soaks into wall voids, mattresses, and furniture, the exact places sprays fall short, and it takes the eggs along with the adults. The equipment costs well over $100,000, which is most of the reason more companies do not carry it.