Recds for an Air Eliminator for a HydroAir unit

joeba

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?

hot_rod

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.

joeba

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

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

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.

joeba

Just got the Minical. Is the guide tab suppose to be bent?

hot_rod

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