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Wall-Mounted Buffer Tank

New, small apartment building in Berkeley going up where they want to use a Navien combi heater for DHW and radiators in each unit. The smallest Navien NCB is 150,000 BTU's and will modulate down to 12,000 BTU's. The total radiator load is ~10,000 and they want it zoned; micro-zoning is a problem. You hardly ever see buffer tanks out West here, but this is a job that needs one.

The mechanical area is tiny. Does anyone have a recommendation for a wall-mounted buffer tank?
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


  • hot_rod
    hot_rod Member Posts: 22,261
    How many gallons? If a small 6 or 12 gallon electric water heater, you can find wall brackets for them or have one fabed. I had a sheetmetal guy bend a bracket that also served as a pan.

    This was a small electric set up for a bathroom floor and shower wall I did years ago.

    Remember over 8 lbs per gallon, so it will take a good solid wall to hang much capacity.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    kcoppAlan (California Radiant) Forbes
  • bob eck
    bob eck Member Posts: 930
    Vaughn makes 10, 20, 30 all the way up to 119 gallon buffer tanks.
    Flexcon makes a fiberglass buffer tank Smallest size is 22 gallons. This tank is advertised on this page.
    Alan (California Radiant) Forbes