air removal

[wj33]

I have a closed circuit water loop on a heat pump system. Pumps are located in basement and top of system is 30 floors high. Water temperature in the loop does not fluctuate more than 25 deg F. The system has no good way to remove air. Although the preferred location for an air separator is at the suction of the pumps, in this case would it make any difference to locate the air separator at the top of the piping loop?

 

[quark]

Ideally you should locate the air separator at the top most point and not at the pump suction. The pump suction method results from cost cutting techniques. At pump suction the pressure will be generally low and you require smaller tanks but when it comes to high rise buildings, your low pressure point will be the top most point.

One thing you have to keep in mind is that air always floats up.

Regards,

 

[micjk]

We use something that sarco puts out on our cooling water system. It is a very simple piece of equipment. It consists of a bowl with float that when air hits it the float drops expels the air and reseats when water hits the float. Occasionally the rubber flap will go bad. We valve it out and install a spare. Very cheap. Maybe this will work for your application. I'll see If I can dig up some info.

Roy Gariepy
Maintenance and Reliability Dept.
Dorlastan Fibers LLC.
Goose Creek, South Carolina USA

 

[Montemayor]

wj33:

What you are describing is what is standardized domestic hot water heating for residences. And what is considered good practice is to allow for air separation at the highest points in the circuit - usually in the form of Tees, but acting as elbows with one flow-through connection pointed upwards and with an extended pipe nipple that is capped. This serves as an air chamber. Several of these are used in the circuit - always at the high spots. In fact, if you have a quality plumbing installation in your house, you probably have these installed in the piping.

The air chambers serve two purposes:
1) To isolate and separate any air or inerts in the circuit;
2) To serve as expansion chambers for the hot water as well as "shock absorbers" against water hammering or sudden shocks.

I've always considered the above to be good practice and have seen to it that my house has liberal air chambers in the hot water circuit.

Unless you have continuous input of air into the hot water, you don't have any need to expel or evacuate it. You say you have a closed circuit, so I would simply keep the air in the system, but with an air expansion tank or chamber at the highest point. The air content, when controlled in this fashion is actually useful and need not be vented.

Art Montemayor
Spring, TX

 

[misterd]

We have protecting our units with air vents sold by Armstrong international inc. It is really cheap and reliable : just check for pressure ratings and chemical compatibility. I would also recommend to install the air vent at the highest point.

Good luck.