Radian Heating Design Help

mbeffa

I am doing an extensive remodel and addition and I plan to install radiant heating.

I designed and simulated the loops in LoopCAD. I have to heat about 2,200 sq.ft, in a very mild (never freezing) California climate. I'll have two manifolds, 4 + 6 loops and five zones. LoopCAD claims I need a total load of 27,000 BTU/hour for the whole house.

Anybody could suggest the best water heater for this application? Internal or external heat exchanger? Any opinions about the Taco <span>Radiant Mixing Block RMB-1 pump?</span>

<span>Any other advice would be greatly appreciated.</span>

<span>Mihai Beffa</span>

<span>Cupertino, CA</span>

Alan (California Radiant) Forbes

Your heatloss

numbers seem a bit low.  Twelve BTU's per square foot is too optimistic.  I'm in Berkeley and a brand new, tight house will usually come in around 17 BTU's per square foot at design conditions, i.e. 36 degrees F.



As far as the heat source, don't scrimp.  Coming from Cupertino, you're probably an engineer (no offense); go for a Triangle Tube Prestige Solo 60.  It gives you a stable, condensing boiler with reset controls.  You could also go with a dedicated 50 gallon water heater, but forget about reset and high efficiency.



As far as using the Taco X-Pump Block, I don't think it would keep the house warm when it gets cold outside; it has its limitations.

CMadatMe

Heat Loss

Dependent on the application of the radiant, the structures layout and finished floor r-values that 27k may be realistic. I'm in NY in a zero degree climate and btus a square foot under 20 are not unreasonable and actually common.



I do agree with Alan as a condensing boiler is the right equipment for the job.