The new CU Rec Center is supposed to be energy efficient and sustainable with LEED's Platinum certification, yet the rec center has made some very strange choices. As a CU alumnus with degrees in electrical engineering and experience with energy issues and as a former member of the CU rec center, I offer these observations.
This past summer as people began to find out that the CU rec center had decided to eliminate saunas as part of its expansion and renovation, the rec center said that saunas use a great deal of energy. This is simply false. When used during cooler weather when the rec center needs to be heated anyway, all the energy used to heat the sauna ends up heating the rec center. No heat is wasted. The heat that escapes from the sauna simply reduces the heat the rec center heating system needs to provide. Additionally saunas are a much more efficient way for people to warm up on cold day. The alternative, a long, hot shower, is wasteful because cold water first has to be heated up and then most of the energy ends up literally going down the drain. So running a sauna during cooler weather when it was heavily used is actually a wise energy decision. And when the weather turns warmer, the sauna could simply be shut off (so it doesn't load the building's cooling system).
The new rec center will have an outdoor, buffalo-shaped, heated pool open from April to October. An outdoor pool is very nice but not energy-efficient, although it certainly helps to run it seasonally. Unfortunately, that season is when most students are gone. If the pool used solar-heated water it would be very sustainable. However it does not. It does however use "waste" heat from chilling the ice rink -- which sounds very environmentally friendly, except that running an ice rink in the summer is not good environmentally.
Chilling an ice rink is a like making ice cubes in a freezer with the door open (and with the condenser coils outside). During cold weather, very little energy is required but during hot weather, the energy use skyrockets. This energy demand profile is problematic environmentally because its peak electricity demand occurs during the hottest weather when overall electricity demand is highest and when electricity is also most expensive. If you are concerned about sustainability and being environmentally friendly, the last thing you want to do is have your peak energy use coincide with peak demand where the grid and power plants are already being maxed out. The environmentally-friendly solution is to shut down the ice rink during the very hottest time of year. (Using the waste heat for an outdoor heated pool does not change the energy demand profile, in my opinion.)
So why did the rec center make these energy choices -- eliminating environmentally-friendly, heavily-used saunas while adding a heated outdoor pool only open half the year when students are mostly gone and chilling an ice rink during the hottest weather when it is an energy hog? My guess is that economic considerations overrode environmental and sustainability concerns. The ice rink and heated outdoor pool can be rented out and bring in dollars. The saunas don't.