Indirect as buffer

[PipeWelder]

Am planning to use a TriangleTube Smart40 indirect for domestic hot water as well as a buffer tank which will be circulating boiler water through a loop with a shell & tube heat exchanger and back to indirect. This loop is secondary of boiler loop and supplies heat through heat exchanger on other side only to low temperature zones requiring no more than 100 degrees. We have total of 3 zones only , other than indirect as priority , with approximately 30,000 BTU' s each. Heat Source is SlantFin CHS110 modulating condensing boiler. Would be interested to know your professional opinion , as I am not a boiler guy , whether this can be done feasibly thus preventing short cycling of boiler . ? Had initially planned on using a Themocon 25 gal. buffer tank to store heat for both indirect tank loop and heat exchanger loop (also providing separation) and preventing short cycling of boiler , however , that's another thousand bucks and not sure if it would be any further benefit ? Am not sure of volume in gals. of outer boiler water jacket of indirect tank either. Thanks for any help possible , PipeWelder

 

[BirchwoodBill]

I am in process of upgrading from a 40 gallon to 85 gallon indirect, then running the dhw through a taco xpb to radiant manifold. Radiant is slated for 70 to 90 degree while the dhw is slated for 125 to 145 degrees. The dhw only needs to supply 120f water to the household. Be sure to do the heat loss and heat gain calculations

 

[Sponsor]

 

[NY_Rob]

The CHS110 can modulate down to 17K BTU's... you indicated your zones can radiate 30K BTU's.

What type of radiators do you have (cast iron, fin-tube, etc...) and what's the length of the radiation in your shortest zone?

 

[Dana]

You all realize the original post is more than a year old, right? (That is the only post he has ever made on this site too.)