Delta T ?

alotlikeearl

I know the recommended delta t for baseboard is 20 degrees and radiant floor is 10 degrees;  what is recommended for cast iron radiators and cast iron convectors?

CMadatMe

What Works

Depends on the application. Condensing boiler would use a Taco VDT pump and work off a 30 if the math works out. Might do the same on a cast iron boiler depending on whose it is. Am I using outdoor reset on the system?

alotlikeearl

Thanks Chris,

I have quoted both a modcon and a cast iron boiler.  If they go cast iron I probably would not use outdoor reset and just let the "VDT' circulator do its thing.  This system has 4 zones total;  1 cast iron radiators, 2 cast iron convectors and 1 baseboard.  I was hopeing a common delta t would work so I could use 1 "VDT" and zone valves. 

CMadatMe

Only Way

To anwser that is to take your room by room heat loss, break it out to the zones and do the math. Can I overcome all zones heat loss running a 30?