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Minneapolis-Honeywell

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mixing valve installed in 1950 and still going strong. Serving copper tubing in the floor downstairs and copper tubing in the ceiling plaster upstairs.





8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab
billtwocaseSolid_Fuel_ManTinmankcopp

Comments

  • hot_rod
    hot_rod Member Posts: 22,268
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    love that gauge too! Thanks for the trip down memory lane.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Alan (California Radiant) Forbes
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    After digging around the controls a little bit more, I came to find out that the boiler is controlled by a Honeywell aquastat below the eaves on the east side of the house. The original boiler was probably something with a high water content like one made by American Radiator Co., but it has since been replaced with a Munchkin. The Munchkin complains when the aquastat turns on the boiler, but the thermostat hasn't turned on the circulator. I'm tempted to make it a constant circulation system.

    This is the oldest outdoor reset system I've ever seen. Those engineers at Honeywell were mighty smart.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,634
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    If it's the one I am thinking of they were pretty common. Looked like an aquastat had two bulbs 1 outside air 1 in the boiler. Problem always the capillary length