Antifreeze in boiler

mjy

**EDIT - by antifreeze, I mean Propylene glycol

Hello - looking to get the forum's thoughts on anti freeze in a boiler. First my set up -



I have a hydro air system with 2 air handles...one in the basement, one in the attic. In the attic, the supply and return pipes have runs of about 20 ft to the air handler. All pipes are insulated with the foam pipe insulation, however, both the pipes and the air handler are in the attic which itself is not insulated.



I'm in CT, so winters can get down to 0 at night and highs of 10 during the day for stretches. If the stretch is long enough, the attic gets well below freezing.



My question is whether anti freeze is a needed with this set up, and if not, what are some alternatives?





The house is my primary home, so it's very rare that someone isn't home during the winter months (except for 8 - 10 hrs per day for work)



Thoughts are appreciated

meplumber

I would use A/F

I am in Maine and I recommend A/F protection in the systems that we install. The fact that you have an air handler in the attic is a no brainer for me. A couple of things to remember.



1. The antifreeze must be checked annually for concentration and pH.



2. While we run a 30% mix up here, you could most likely get by with a lesser mix in CT.



Your heating professional should know what concentration to run.



Good Luck.

mjy

.

Thanks MEPlumber.  Exactly the feedback I'm trying to get in whether people tend to use it or not based on my setup. 

I'm not crazy about the stuff, but don't exactly like the thought of it being in the attic without anything if we lose power. 

My thought on that was that I am usually home during the winter (except for 10 - 12 hours during the day for work), so even if I lost power it wouldn't go too long before I hooked up the generator.  Not sure if it would freeze is less then 10 - 12 hours on the coldest day of the winter.

Have you had any corrosion issues w/ using it?  My oil company is saying that if it's added and it causes corrosion damage, then my service agreement will not cover the parts.  Not sure if this is something that is commonly seen

Jamie Hall

This may sound silly...

but you do run anti-freeze in your car, don't you?  I hope so...



You shouldn't have corrosion problems if, as MEPlumber recommends, you check the concentration and pH at least yearly.  And -- and this is a big and -- you use a product which is compatible with the materials of your system and contains corrosion inhibitors.

kcopp

I am not....

a fan of glycol and I rarely use it in my systems here in New Hampshire. However in your case it sounds like a good idea. I presume that the attic is in unconditioned space (there is no spray foam on the roof rafters).  The guys have very good points... one addition is that BEFORE the glycol goes in that the system should be throughly cleaned and flushed . If not it will ruin the inhibitors and significantly shorten its life. kpc

Mark Eatherton

Aunty Freeze as I know her....

She's a fickle old broad.



She shouldn't be employed in every case. I'd employ her under any one of the following conditions;



1. Snowmelt (DUHHHhhh)



2. SItuations whereby the home can go for long periods of time without supervision or no means of knowing you've had a mechanical failure.



3. Possible loss of fuel or electricity without knowing about it...



4. Structural preclusion. (your case, where the piping is intentionally exposed to a freezing potential.



Most glycnoid manufacturers who put corrosion inhibitors in their glycol do not recommend a solution of less than 30% to insure proper inhibitor levels. But bear in mind that they have a vested interest in selling you their product...



As others have said, I would clean and condition the system with something like Rhomar, then induce the MINIMUM allowable glycol percentage int the system. Oh, and don't guess about the concentration. Mix as you induce, and avoid over/under shooting the glycnoid concentrations.



PS EDIT: Do NOT leave the make up on if there is glycol in the system. Otherwise you may discover inadvertent dillution... Do a local search for Glycol PIG and see what pops up.



ME