View Full Version : using waste heat from walk in cooler

12-31-2013, 09:03 PM
I am in the process of installing a walk in cooler for our new 15bbl brewery. It will be a small cooler because of space constraints and I have a mechanical engineer helping with the design of our brewery. I would like to design our system to use the excess heat from the condensing unit to pre-heat domestic hot water, or stand-by water for brewing or radiant space heating. Does anyone have any experience with these applications? My mechanical engineer and refrigeration guys seem skeptical.

I want to do this to reduce costs and be eco-friendly. Any friendly advice? Any equipment I should be investigating? Any idea of pay-back periods? Any pitfalls? Am I nuts?

Gananoque Brewing Company

01-01-2014, 12:37 PM
These are typically refrigerant hot gas to water heat exchange unit called " Desuperheaters " in the trade.
You will need one that is of design BTU size that will work with your unit and not create more problems which can happen if it is not installed with some savvy and correct consideration given to the effect on saturated condensing pressure. Thiis type of heat reclaim is not commonly seen on this type of application and may not be seen to have much real benefit. Also it may not be advised by the Condensing unit OEM and it could possibly void the warranty unless the mod is approved.

01-02-2014, 09:57 AM
You can definitely recover the heat from the condensing unit servicing your cold room.

Therma-stor is a manufacturer of heat recovery units and probably a good place to start. As Warren noted, installation is critical- these units installed incorrectly can result in system issues and quickly erase any added benefit in water heating costs and system efficiency. You can realistically pre-heat water into the 140-150 F range on a refrigerant R404A system. As a rule of thumb you can recover around 30-50% of the rated capacity of your cooling system- for example a 5 hp System rated at 40,000 BTU/HR cooling capacity, could provide a heating source of 12,000-20,000 BTU/HR.

There's some good information on their website as well as calculator to determine its feasibility: http://www.thermastor.com/Heat-Recovery-water-Heaters/

We offer factory installed onboard heat recovery on our chiller systems, but due to costs these aren't commonly incorporated until you get above the 20-30 HP size range of system. It is less common to offer this option in brewery applications since breweries will often recover heat while processing Wort, than it is to offer in markets such as wineries and dairies.

Good Luck,



01-02-2014, 10:19 PM
good feedback. thanks guys.