Freeze point

Timco

So I checked freeze point on a system that had a leak. Nearly 100% water. Propylene. I drained the house and refilled with fresh glycol, but just got the freeze point down to +17*F. That took 15 gallons. The driveway snowmelt loop is below the boiler level so it will not just drain. Can I pump glycol in one side and push the water back to exchange that water with glycol? Cust wants freeze point to be 0. No idea how many feet of tube is in this place or under the driveway.



Thanks, Tim

Charlie from wmass

try air first to blow out the lines

or you will need to keep adding antifreeze and draining mix until you reach the right blend. If you know how much you added to get to 17 you should be able to go backwards and see what the system volume is and then figure how much you now need to add. Oh and Tim Happy New Year!

icesailor

Freeze points:

Here's how I fill systems. I need to measure within reason, how much fluid is in the system. I carry a portable air compressor in my truck at all times. I have a "rig" that I can connect to any water system and blow the water out of the systems. I winterize houses this way. I drain plumbing and heating systems this way. There should be some way of purging this system. Blow compressed air into the system and purge the water in the system into a 5 gallon bucket. You need a few. Measure how many buckets of water you purge out. That gives you a good estimate of how much water is in the system.

You need to be careful with underfloor systems that you can't see unless you, personally have done the install. I have seen some really long loops under floors. You should be able to purge the snow melt zone. Therefore, you should be able to purge the water in it with air. Therefore, with the above method, you can measure the amount in the zone. If there is a leak in the system, you had better fix it. If you need to leave the fill valve open because it looses water, you have a problem. It is easier to fix or abandon the defective zone than the cost of always adding solution.

If the system is properly zoned and isolated, you can use the compressed air to test the zones and find the leaker.

It's a PITA.

But you knew that.

Timco

Thanks.

No fill valve because the entire system is glycol. Terrible design. RBI 350K running the show. Just swapped the HX on that. Axiom glycol pump which is super slow.



There were leaks at the boiler for some time, and the HO just added water to the Axiom, rather than glycol. Blue stains in a few places that I will address while it is down. My supplier has 10 buckets on hand but I think I may need to find a source for more just in case. Big house, 40' long drive.

Mark Eatherton

Articles of Glyconization....

http://contractormag.com/hydronics/cm_column_113/index.html



Unfortunately, Contractors Magazine didn't do a real good job of chronicling articles during their transition in ownership, and part 2 got lost in the shuffle. If memory serves me correctly, the second part of the article talked about premixing and pumping the glycol into the system. I use marks on the wall of a bucket to gage glycol to water premixing. If you want a 50% mix, mark the bucket at 6" and 12". Fill with glycol to 6" and top off with water to 12", then pour into the pumping bucket and let 'er rip.



As for a pump, I use a high head sump pump, and pump the glycol from the pumping bucket into the system through the system distribution pumps. Remember, pumps in series add their pressure potential (head) together and aid in purging. Set your fill and purge assembly up so that pumps in series is possible, and pumping will be easy. Fill and purge with one to two circuits open at a time, and run it until the big bubbles quit coming back, then move on, and never dead head the fill operation or you will do an inadvertent pressure relief valve test, and it usually only happens while the homeowner is standing there looking at you... :-) OOPPpppssss 8-)



As it pertains to purchasing glycol, use caution. Not all glycol is the same. In order to hold costs down, some manufacturers premix to a lower percentage, and if you further dilute it as I suggested above, you will end up with a uniformly weak glycol solution. I prefer to use 100% glycol, and mix to my needs. On larger jobs, the wholesale supplier can provide you with "Totes" of glycol. They are fork liftable plastic storage containers that fit in the back of a pick up truck to assist in expediting glycnoids to the job site.



As for estimating, if you don't know for a fact exactly how much tube you have, guess high as it pertains to tube density, and you can always return the unopened glycol. Snowmelt is typically 9" O.C., RFH is typically 6 to 12" O.C. Manufacturers have charts for converting tubing linear footage to gallons.



If you premix your glycol as you pump it in, you can always go grab more glycol to finish the job. If you pump in too weak of a solution, you have to play the pull and pump game, which is expensive and unprofessional.



I am in the mountains right now, and don't have access to the original articles, but whence I return to Denver, will see if I can find Part 2 of the articles.



Happy New Year Tim and all.



ME

icesailor

Pump in, blow out:

If you can fill it in or pump it in , you can blow it back out.

I drain and winterize a lot of houses. Back when, we always pitched thing to drains and had high points. Second floor series loops had drain points between risers. The whole structure could be drained safely with no splits unless you missed something.

Today, many installers think that a "low point" is a bad time in their lives and pitch is a musical term. Drips are something that comes out of a leaky pipe. When you are faced with a two story, multi-zoned system to drain, and the only drain is at the boiler, you either anti-freeze it or you blow it out.

I once did a house with 6 zones of series looped baseboard in a two story house with no drips. It was piped with isolation valves on each zone. I "sucked" out all the water I could with a water pump. I took 35 gallons of water out. I then, pumped the antifreeze in from the other side so that any water left in a zone was "pushed" back out. I took an additional 12 gallons of water from the system. Water that came out until the anti-freeze came. I added the appropriate amount of anti-freeze to make it safe. It is fine. I use my third world anti-freeze injection pump to put it in.

Now, when I want to drain a system, I just blow it all out with air. Never had a break.