adding glycol

[dandyme]

is there any way to avoid draining chiller water to add glycol

i don't recall seeing any hose bibs near pump

[Octopus]

You "in theory" "could" Valve off the pump suction until it pulled into a vacuum and draw in glycol in that way...... If you have access that way.... OR make your own shot tank, Install a shot tank.... OR overcome loop pressure and pump in glycol using like a gear pump??
Is that what your asking?

[basshound71]

Drain a little, add a little. Good luck.

[dandyme]

yea, we've done drain and add

looking for a quicker way

[Octopus]

shot tank

[klove]

is there any way to avoid draining chiller water to add glycol

i don't recall seeing any hose bibs near pump

No. If the system's full of liquid except for space in the expansion tank, the only way to add more liquid is to over-pressurize, and you ain't gonna get much in doing that. Most of the time, what sounds difficult is really the easiest and least time consuming way - drain completely (unless you know the system volume in gallons and the current mixture), test and adjust mixture, pump back in using a utility pump, work the air out, and continue to pump in until pressure stabilizes. Log the system volume while doing this and as the glycol degrades or is lost, you'll know what to put back in for any given amount of loss without doing a complete drain.

Lack of hose bibs is a minor detail that's easily remedied....

[Randy S.]

Is a shot tank the same as a pot feeder?

[Randy S.]

We've got one coming up where our guys will meter how much water is drained out.
Supposedly the system volume is already known, and we know how much we're going to put in.

[amickracing]

I used a transfer pump when I have to add glycol to a system, just find a port somewhere (hopefully with a ball valve) and put a hose fitting on there.

If the system is already full I usually drain some of the system into a barrel then add the glycol to replace what I took out. It can kind of be a crap shoot when you do this. Just remember, take out a bit more than you think you need, add the glycol a bit at a time and run the pumps for a while and keep testing. You can always pump some of the other stuff back in if you get it too strong.

I try to use a small barrel if possible (30 gallon) so you can move it easily. If there's room I usually try to hang onto it and keep it around. If you have a little glycol left over pump it into the barrel and stir it up, mix it to the same % that the loop is (or what you want). If you have a leak somewhere and loose some pressure you can just pump it in from this barrel and it's already what you need.

[flange]

you could create a restriction in the suction of the pump, drain some out prior to the restriction while pumping in the suction of the pump, but its just easier to drain and fill. If you can calculate system volume it is much easier.

[johnnykling]

why do you ned to add glycol ? is the system designed for gylcol ? are you trying winterize the circuit ? there are alot of ?s like these that i have when someone is wanting to put glycol in a system that never had one before

[klove]

why do you ned to add glycol ? is the system designed for gylcol ? are you trying winterize the circuit ? there are alot of ?s like these that i have when someone is wanting to put glycol in a system that never had one before

Who said it never had glycol in the system?

[dandyme]

this jewel runs year round, i think this one lost a barrel last year

[flange]

I know a guy who didnt think his machine needed glycol, and now has a popped 200 ton evap from last winter on a seven year old machine, ooopsie.

[milkyway]

I know a guy who didnt think his machine needed glycol, and now has a popped 200 ton evap from last winter on a seven year old machine, ooopsie.


holy cow., now that is scary., that is alot on ones shoulders

[mccann]

What is the effect of too high a % glycol?

I used a transfer pump when I have to add glycol to a system, just find a port somewhere (hopefully with a ball valve) and put a hose fitting on there.

If the system is already full I usually drain some of the system into a barrel then add the glycol to replace what I took out. It can kind of be a crap shoot when you do this. Just remember, take out a bit more than you think you need, add the glycol a bit at a time and run the pumps for a while and keep testing. You can always pump some of the other stuff back in if you get it too strong.

I try to use a small barrel if possible (30 gallon) so you can move it easily. If there's room I usually try to hang onto it and keep it around. If you have a little glycol left over pump it into the barrel and stir it up, mix it to the same % that the loop is (or what you want). If you have a leak somewhere and loose some pressure you can just pump it in from this barrel and it's already what you need.

[amickracing]

There are a few.

The best conductor is just pure water, unfortunately that doesn't always work by itself. As you add glycol you loose some efficiency since the glycol doesn't transfer heat quite as well as water. When you are figuring the heat transfer water is the constant you use 1 in the formula. When you start throwing glycol in it goes down, somewhere in the neighbor hood of .9 give or take.

Of course this depends on if it's ethylene glycol propylene glycol, but there's not a huge difference between them.

The other issue of glycol is it gets harder to pump. So if you're pumps are barely making it with just water, you'll have flow issues when you get glycol in there. The temp of the loop also makes a difference,, ethylene will flow a bit better than propylene when it gets really really cold (think ice arena). Generally propylene is the standard choice unless other factors are involved.

The concentration will vary from area to area. Around here we shoot for around 30% in most everything. There's a few systems I have put around 40% in, but this is a chilled loop that is down through the winter, and this place gets some brutal winters. I don't have the facts in front of me, but I believe once you get above 45-50% you really start loosing efficiency and can run into problems. But, 50% is good for around -30 deg, that's just the freeze point where ice crystals start to form in there, the actual "frozen solid" burst point is usually 10-15 deg lower (ballpark). So... that's pretty dang cold.

[mccann]

Thank you, excellent.