Make Up Air
Make Up Air
(OP)
I am adding a make-up air unit to an existing apartment building. The building has a 2-pipe hydronic system (Simultaneous cooling/heating is not avaliable). How can I condition the outside air without subcooling the cooridor served? There is virtually no load in the corridor. I am considering controlling to corridor space temperature (dry bulb) while watching corridor relative humidity. If the relative humidity exceeds a maximum setpoint (adjustable) I will override the space dry bulb control and subcool the space until an acceptable relative humidity is achieved. Electric or hydronic reheat is not avaliable. Also, would you use the ASHRAE Fundamentals Cooling DB/MWB or DP/MDB weather data for your outdoor condtions?





RE: Make Up Air
If your ambience is humid, I will prefer 2% value of WB/MCDB. Otherwise it is 1% of DB/MCWB. This is basically a designer's choice and depends on whether he likes to walk on a tight rope or not.
Regards,