A supermarket refrigeration system can do more than keep food cold.
It can potentially heat the building too.
In the modeled hypermarket application, combining direct-air CO₂ heat recovery with air-source heat pumps reduced space-heating energy by 53% compared with the baseline design.
Total modeled energy consumption fell 35%.
Refrigeration Produces Enormous Amounts of Heat
Refrigeration does not destroy heat.
It moves it.
Traditionally, the heat removed from refrigerated cases is rejected outside.
CO₂ systems can produce discharge temperatures high enough to make that waste heat useful elsewhere in the building.
Recovered heat can support:
space heating,
domestic hot water,
dehumidification,
and slab heating.
CO₂ Produces Higher-Temperature Heat
According to Copeland, R-744 systems can produce discharge temperatures 20°F to 40°F higher than conventional HFC systems.
Real-world systems can reportedly generate useful water temperatures of roughly 140°F to 190°F.
That makes the heat usable for applications that previously required separate heating equipment.
Why Contractors Should Care
This changes the contractor scope.
A refrigeration plant that also contributes to heating requires coordination between:
refrigeration,
HVAC,
hydronics,
controls,
and hot-water systems.
That creates opportunities for contractors capable of integrating multiple mechanical systems.
The Takeaway
CO₂ refrigeration is often sold because of its ultra-low GWP.
Its more interesting long-term advantage may be something else.
The refrigeration system can become a heat source for the rest of the building.
