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Recds for an Air Eliminator for a HydroAir unit

joeba
joeba Member Posts: 23
I have a HydroAir unit located in the finished attic space of my home. There is no air eliminator. Unfortunately I don't have the greatest setup because of circ is on the return.
Static pressure is set to 15psi. Zones valves and a Taco 007. Other than the run of the mill Hy-Vent, is there a recd for an air eliminator for this setup?

Comments

  • hot_rod
    hot_rod Member Posts: 16,875
    M<ake sure you have a good air seperator, installed in the best location at the boiler. That does most of the work.
    Additionally you may want a high point vent to eliminate air where it gets trapped up high.

    This vent is unique in that it includes a special hydroscopic cap. So if the vent ever fails, gets a speck of dirt in the valve assembly, the cap has a second shut off function.
    Help prevent a leak through the ceiling, perhaps.

    You want at least 5 psi pressure at that highest point. So the elevation from the boiler to that highest vent X .433. Then add 5 psi to that.

    The 5 psi positive pressure assures the vent can eliminate air well, but also shut off the needle valve when air is gone.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • joeba
    joeba Member Posts: 23
    Thxs Hot Rod. That Minical is a good solution since a leak could cause damage to the ceiling below. I have to check the secondary pan (the AH does AC), it might catch any leaking. Unfortunately for me, I just have a crappy air scoop (with less than 18 inches of piping to it) with a hy-vent. I'm waiting to replace the boiler and all it's near piping and do it right and not the spec-house special piping I have now.
  • joeba
    joeba Member Posts: 23
    BTW, I used that formula (.433 x h+5) and that is how I came up with the 15 PSI. Watt 911s instructions tell u to use 3 PSI. I just changed out the expansion tank (which I can isolate) and PRV. Also changing o-rings on the honeywell zone valves. Doing all of this because I have antifreeze in the system (about 25-30%) and I am ready to change it out and I want to make sure I address any issues so I minimize the chance I have to drain the system to make a repair or having to add makeup water. All of these things are issues I have to deal with on this system in the past 20 years of life with antifreeze.
  • hot_rod
    hot_rod Member Posts: 16,875
    Yeah, antifreeze brings along some baggage. Test it every couple years, with weak solutions you may want to add a boost package every 5 years or so.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • joeba
    joeba Member Posts: 23
    Just got the Minical. Is the guide tab suppose to be bent?
  • hot_rod
    hot_rod Member Posts: 16,875
    The tab is on there to help coax air bubbles up into the vent when screwed into this type of purger

    If you are screwing into a fitting it will be fine. As long as it doesn’t hit a ball valve or other roadblock
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream