Ellis’s vast knowledge and experience in the HVAC business, and his training on furnace heat exchangers has allowed him the opportunity to view every aspect of furnace applications in every part of the country. He is, by nearly all of the individuals he has trained, the expert when it comes to furnace heat exchangers. Knowing and teaching what can happen when a furnace heat exchanger is cracked, or when a furnace is not installed properly, has allowed Ellis to be called as an expert witness for several carbon monoxide poisonings and even deaths, due to carbon monoxide leakage from a faulty heat exchanger.