Greenheck’s direct gas-fired make-up air units now use R-454B, an A2L refrigerant mandated by the Environmental Protection Agency with low potential to contribute to global warming. The units incorporate third-party-tested refrigerant leak detection and mitigation systems. The Model DGX units, which provide 100% outdoor air, also feature packaged direct expansion (PDX) cooling, housing all cooling components in one compact rooftop unit.
The design also includes microchannel coils, which have parallel flow tubes with tiny channels that carry refrigerant. Microchannel coils are an average of 40% smaller than standard coils, use 50% less refrigerant, and transfer heat 40% more efficiently. Burners are 92% efficient and capable of a 30:1 turndown.