Heat Rejected to room by VSD's

[RRD]

I am looking at providing A/C to a switchroom which includes VSD of varying manufacture.

Aside from asking the supplier for possible information which is a little sketchy at times (sales staff who read catalogue data back to you but can provide no further insight), does anyone have a rule of thumb for determining the heat rejected to the room.

I seem to be able to obtain cooling airflow rates for some of the VSD's but I cannot obtain a reference temperature rise in order to determine the heat rejected.

I do not want to significantly over size the unit due to the loads off the VSD's.

Any help would be appreciated.

 

[pablo02]

Check you catalog data; most that I have provide tables showing watts lost vs. min/max speeds... convert to BTU's per hour for determining cooling loads..

 

[pablo02]

Also, there is a rule of thumb: use 2 to 6% of the (ASD)drives kVA rating (I have not used this nor have I compared it to the manufacturers' data)

 

[mdonner]

Rule of thumb is 3-4% of VSD nominal rating.