The Colorado School of Mines converted a greenhouse into a classroom, and they chose Coolerado and Mountain States Equipment Company for a combined cooling and heating unit.  For the ultimate in energy conservation, the unit has a variable frequency fan drive controlled by room sensors and tied into the campus wide control and monitoring system.

The air conditioner has the ability to provide 9 tons of cooling one minute, and can switch to heating mode the following minute.  The heat is obtained from the buildings hot water system through coils located in the discharge plenum.

The photograph above shows the air conditioner with the intake plenum door open on the left, the fan and filter door open in the middle, and the discharge plenum door open on the right.  Notice that you can see through to the motorized dampers and to the space outside when viewing the intake plenum.  This unit can also recirculate the room air via the return air duct on top of the intake plenum.

In the photo at left you can see the insulated hot water pipes which feed the heat coils located above the Coolerado heat and mass exchangers inside the discharge plenum.