Radiant Heating temp for a 1940’s house
Hi. First time poster here. I have an original gravity boiler that supplies my heat through what I think was called convectors, very heavy cast iron with steel fin radiators. The boiler has developed pin hole leaks that seem to heal themselves! I want to replace the boiler this summer with a Radiant system.
I have access to the main floor from my basement and my plan is to use BlueRidge Co. aluminum extruded 4′ x 6″ heat transfer plates in the 13′ long joists ( 6 plates per joist ). So two runs per joist with 1/2 Pex ( 250′ loops ). These plates are 6″ wide so 12″ of plate coverage for each joist cavity. The plates are 1/16″ thick. I am hoping to use 100 degree water for this system so I can use a condensing boiler in the 95% efficiency zone. My upstairs is another problem. No access from beneath. My solution, maybe, is to use the original convectors with 100 degree water to heat the upstairs as a second zone. I think they oversized these convectors because number one they were gravity feed ( I will be using a pump ) and two the house was fairly leaky. I have been replacing all my windows with Andersen 400 double glaze and upgrading insulation everywhere so I am hoping 100 degree water will work. We keep the temp at 65 upstairs in the winter so that may help. Any feedback would be welcome. Oh yeah I am working on a Beopt energy calculator to get a better understanding of what I need to upgrade in terms of insulation, air tightness ect. Not done yet.
Tom, Minneapolis Minnesota
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