Ice Rinks - Ice Sheet A/C credit

[chunkymenudo]

In an ice rink design does anyone else out there take the ice sheet into account when caclulating the A/C load? ASHRAE says that up to 28% of the ice making refrigeration capacity is for convective and radiant losses to the space. If that is so, would it be a safe bet to count say 20% of the installed ice making tonnage as a credit. A Munters rep claimed that you can claim as much as 40 to 50 tons of credit. Last, I have run the radiant and convective calculations for ice rinks (ASHRAE 1998 Refrigeration Handbook, Chapter 34, page 34.3) and I get about 60 tons. Bottom line, conservatively I believe at least 40 tons can be available. While this is a credit in the summer, conversly it is a problem in the winter.

Am I wrong?

 

[sterl]

Ice Rink air conditioning should be designed as much to maintain the ice condition as for the comfort-air condition...

Introducing warm, dry air will cause minor filming but major sublimation, which means the ice will need deeper shaving and a greater film of fresh water when re-conditioned, which can represent a considerable additional energy load depending on how the snow melting pit is handled. High intensity lighting tends to aggravate...The convective results will also cause drip and a potential aestehetic or maintenance issue to the interior ceiling or roof framing. It will save on the de-humidifier operation...

Introducing cool moist air causes fogging and soft, "dirty" ice and will create a load on the dehumidfier operation. In cold climates, any


As to arrangement: Target condition Air Handlers with VFD often end up near grade, the structural characteristics don't usually tolerate roof mounts..
VAV and air distribution should be designed with consideration of the cavity ratio of the building. The ice sheet promotes convection but in the absence of a drop ceiling or similar, the conditioned air wants to be introduced around the perimeter and agitated at the peak, exhausted near the top but outside the perimeter of the ice surface.