Not necessarily. Some of the better brands out there tend to include heat recycle or recirculation in their standard offerings. Accudraft definitely does. In fact, Accudraft almost forces the buyer to “specially request” a non-recirculating system simply because the benefits are so great. Heat recycle or recirculation is a method of bringing the exhausted air back through the heating unit so the heated air is 1. Not wasted, and 2. Helps heat the newly heated air. The results are faster cure times and less fuel usage. Some brands simply do not carry the proper certifications to truly recycle heated air and the verbiage on the product will say “air recirculation” or “air mixing” or “air slow down” etc. if you have any doubt, ask your manufacturer if the system you intend to buy has a 80%-20% recycle or better. That will address the question point-blank and the answer should be yes. 80-20 or better heat recycle does not generally cost any more than a system without it. It’s a matter of some specific parts and the certifications to do it. Cost is almost the same. There really is no reason for an automotive system NOT to recycle heat. If the heating unit is very far away from the exhaust point, say on a very large truck paint booth (the paint booth heater is on one end and the exhaust point of the paint booth is all the way at the other end), it may seem expensive to run the duct that would link the two point for true paint booth heat recycle. However, that is a one-time cost that would pay itself back pretty quickly, especially on a truck paint booth. When it comes to energy efficiency, the bigger the paint booth, the bigger the argument for a paint booth with heat recycle.