I'm ramping up a Garn1500 and need to make some design decisions as to how low I can practically pull my storage temp. This number would drive the sizing of a few panel radiators that will cover a couple areas that I didn't heat with either in-slab or Warmboard. I also plan to use the Garn for pre-heating well water for domestic hot water in a conventional water heater. There will also be an LP fired backup boiler in the system for "just in case". The rads will be the most "temp hungry" of the lot, but get pricer as you upsize them to take advantage of the lowest stored water temps.
Current thought would be maybe pull the Garn as low as 125 with a deltaT of 5 thru the main HX. This would provide 120 to the rads and appears to be about the practical limit without getting too huge (and also expensive) for the rads.Running anti-freeze in the entire secondary is also in the plan and will further impact their sizing.
Any input as to considerations as far as pulling Garn storage temp that low as well as practical limits on sizing rads would be appreciated.
Dan
Current thought would be maybe pull the Garn as low as 125 with a deltaT of 5 thru the main HX. This would provide 120 to the rads and appears to be about the practical limit without getting too huge (and also expensive) for the rads.Running anti-freeze in the entire secondary is also in the plan and will further impact their sizing.
Any input as to considerations as far as pulling Garn storage temp that low as well as practical limits on sizing rads would be appreciated.
Dan