I just want to make sure I'm doing the right thing here before I dig myself a hole that I can't get out of. I have a 2400 sqft home which includes 700 sqft in the finished basement that never gets heated. I just purchased a Harman SF-160 Wood Boiler rated at approx. 90,000 BTUs to heat a max 2200 sqft home. My plan is have the boiler piped in series with the oil boiler to heat the DHW coil in the oil boiler. Down the road when I get a storage tank, I will pipe the wood boiler in a parallel loop with the oil boiler. Additionally, the new wood boiler is being placed in the garage, about 30ft away from the oil boiler located in the basement. So the loop between the two boilers is about 70ft (35ft supply + 35ft return). The circulator pump is a grundfos UPS15-58FRC with a max flow range of 17GPM and head range of 19ft.
The boiler manual suggests 1-1/4" pipe between the two boilers so I bought 1-1/4" PEX tubing. However, the pex tubing is NOT 1-1/4" ID, it is more like 1-1/16" ID. 1-1/4" copper pipe can handle around 160,000 BTU's/h but 1" copper can only handle 75,000 BTU's/h which is less than my boiler is rated.
So what are the ratings of the PEX pipe? Are BTU/h ratings based SOLELY on pipe size or is pipe material also a factor? If pipe material is a factor, does PEX tubing flow more or less than copper? If pipe size is the sole factor, then what kind of MAX BTUs/h should 1-1/16" pipe be able to carry??
Thanks
The boiler manual suggests 1-1/4" pipe between the two boilers so I bought 1-1/4" PEX tubing. However, the pex tubing is NOT 1-1/4" ID, it is more like 1-1/16" ID. 1-1/4" copper pipe can handle around 160,000 BTU's/h but 1" copper can only handle 75,000 BTU's/h which is less than my boiler is rated.
So what are the ratings of the PEX pipe? Are BTU/h ratings based SOLELY on pipe size or is pipe material also a factor? If pipe material is a factor, does PEX tubing flow more or less than copper? If pipe size is the sole factor, then what kind of MAX BTUs/h should 1-1/16" pipe be able to carry??
Thanks
