Dear all,

I was using a VAV system, with the reheat source being the hot water loop. I specified the Reheat delta temperature by trial and error to 20F. Everything is fine.

Now I got updated info from the client saying that the source of the reheat is electric. I am getting an error message:

"Hot Water Loop has zero design flow. Check input for consistency, or specify design loads."

I read a couple of discussions. I understand that many factors will affect this issue. The "Hot Deck Maximum Supply Temp", the "Reheat Delta Temp", and the "Zone Entering Max Supply Temp".

First of all, is the sum of the first two equal to the third?

My main question is how to get reasonable results, knowing that the main heating source is the hot water loop, and the electric reheat is just to fine tune the temperature of zones experiencing different loads or so...

I played with all values but I can't figure out the pattern. I know that the design temperature of the zones is 70F, and that the temperature that is supplied to the zone should be 30 degrees higher than the zone temperature (70+30=100F).

Any advice on how to choose the "reheat delta temp" and the "hot deck maximum supply temp" is greatly appreciated.

Many thanks,

Omar Katanani