Overview Building Features Grade JK-6 Grade 7-12

Energy Recovery

Real Time Data
a Return Air Temp °C °C
b Wheel Supply Air Temp °C °C
c

Exhaust Air Temp °C

°C
  Fresh Air Temp °C °C
d Outdoor Air CO2 PPM PPM
e AHU1 Supply Air Temp °C °C
e AHU1 Supply Air Humidity %RH %RH
e AHU1 Supply Fan VFD %Speed %Speed
e AHU1 Supply Fan VFD Amps Amps
f AHU1 Exhaust Fan VFD %Speed %Speed
f AHU1 Exhaust Fan VFD Amps Amps
f

AHU1 Exhaust Air Temp °C

°C
f AHU1 Energy Recovery Discharge Air Temp °C °C
g AHU1 Return Air C02 1st Floor PPM PPM
g AHU1 Return Air C02 2nd Floor PPM PPM
g AHU1 Return Air Temp °C °C

Energy Recovery - Mechanical Room

An air-to-air energy recovery system takes opposing air streams and extracts energy from the exiting stream to be released back into the incoming stream.  The net result of this exchange is a reuse of energy that would have otherwise gone to waste.  There are several configurations of air-to-air energy recovery devices; the most common found in building heating ventilation and air-conditioning (HVAC) systems include enthalpy wheels, plate heat exchanges, run-around loops, and heat pipes.

Enthalpy wheels may also be referred to as energy recovery wheels, rotary type heat exchangers, or total energy wheels.  An enthalpy wheel (which resembles a slowly rotating honeycomb) has the ability to exchange both heat and humidity from one air-stream into another and as such can achieve energy recovery effectiveness ratings in the range of 60%-70%.  As the wheel rotates between the streams, energy is collected on the high energy side and discharged to the low energy side.  This is beneficial to the HVAC system year round as cooling and dehumidification energy associated with conditioning ventilation air is reduced in the summer and heating and humidification energy for conditioning ventilation air is reduced in the winter.

Energy Recovery - Mechanical RoomHow it is used in the school:

Each of the five (5) air handling units (AHUs) serving the building is equipped with an enthalpy wheel to extract energy from or reject energy to the building exhaust air.  The wheel is positioned in the middle of the AHU so that half of the wheel is in exhaust air stream and the other half is in the incoming air stream.  In the heating season, the heat and humidity from the exhaust air stream is collected by the wheel and discharged back to the incoming supply air stream.  In the cooling season, the heat and humidity from the incoming air stream is collected by the wheel and discharged back to the exhaust air stream and does not enter the building.  If the energy and moisture levels are equal in both streams, there can be no energy transfer and the air may bypass the wheel section of the AHU entirely. 



Greater Essex County District School Board