Antifreeze in boiler

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Old 12-09-11, 12:32 PM
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Propylene glycol in boiler

** 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
 

Last edited by mespn; 12-09-11 at 01:34 PM.
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Old 12-09-11, 01:49 PM
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Antifreeze

There is a product called Cryotec, and there may be others. I am away about 6 weeks in the middle of winter, and I use antifreeze in case there is a power interuption so at least I won't loose the heating system. I am working on the rest. You loose a small percentage of heating capacity with antifreeze but I think it's worth it. You use about a 50/50 mix, and every 5 years or so add a little inhibiter to freshen the PH, and the other good things it does. Oh yeah, really insulate those pipes in the unheated attic and anywhere else while your at it. You will save some heat, and some money too.
Sid
 
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Old 12-09-11, 02:01 PM
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Thanks for the reply Sid. I definitely agree that if I left the house for weeks at a time during the winter, antifreeze would be a must.

However, in my situation where I am at the house throughout the winter, I'm wondering if it's necessary. If I lost power, the longest the house would sit there before I could get the generator running is 10 or 12 hours (while i'm at work) . Wondering if insulated pipes which previously had 180 degree water in them can really cool down and freeze up that fast.
 
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Old 12-09-11, 02:52 PM
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Antifreeze in a hydronic system is messy when if comes time for performing maintenance or repairs. Special equipment is needed to add antifreeze to a system.
 
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Old 12-09-11, 03:36 PM
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Ugh. Air handlers in attics are such a bad idea. I don't understand when new homes are designed like this. Anyhow, how close to the ceiling below are the hydronic lines? My suggestion is to put those pipes and hopefully the air handler, in the conditioned space of the home. I would do this by removing the insulation below the pipes and handler, and putting it above those items. If you can construct boxes out of rigid foam to cover everything, I think that would work the best. For the pipes, you can add batt or blown insulation on top of the foam boxes. The box for the airhandler would need to be removable for maintenance. So I would just use foam board to get the desired R value for that.
 
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Old 12-09-11, 04:04 PM
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The glycol heating systems I have experience with has the glycol delivered to the system with a pressure pump.
You would have a reservoir tank filled with glycol.
You then use a small jet pump and pneumatic tank to draw up the glycol from the glycol tank to supply the boiler through a prv.
 
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Old 12-09-11, 07:51 PM
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My question is whether anti freeze is needed with this set up, and if not, what are some alternatives?
Alternatives? I wouldn't want a home with hot-water heat that wouldn't be occupied or looked in on regulary. Antifreeze is not a real desirable option. Better to have electric baseboards or forced air heat, in my opinion.

Of course, there are internet- or telephone-based remote alarm systems. But they may be kaput in a power failure. Auto-start, standby generators? The best option is to have a neighbor look in on the house who can call for help, if needed. There are more things besides freezing that can interrupt heating.
 
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Old 12-10-11, 07:28 AM
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Antifreeze

I have used antifreeze for about 25 years with no real problems. You just need a little giant pump and a five gallon pail.
Sid
 
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Old 12-20-11, 03:38 PM
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same boat

hey mespn...what did you end up doing?

I am in the same exact situation. Just moved to CT this fall & have the same setup.

I hear "bad" things about antifreeze in the pipes (corroding, etc...)

I already have it in the system but was thinking of flushing it out completely.

I already insulated the pipes in the attic (only about 4' long) and was thinking I can put that pipe-heating electric wire around them to keep them from ever freezing.

Plus, the local oil co wants like $700 to refill the system with antifreeze.

Looking fwd to your response!
 
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Old 12-20-11, 06:26 PM
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Not sure what source would be saying "bad things" about heating antifreeze?
Is it possible that someone is using automobile antifreeze to base this on?
You need to use inhibited propylene glycol heating antifreeze and the inhibitors should be tested with a test strip every year to make sure it is still effective.
Heating propylene glycol will keep your system cleaner than using water.

You might want to find out if you have heating antifreeze before you consider dumping it and if you do all you need is to test the inhibitor.
 
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Old 12-20-11, 07:01 PM
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I agree with GregH. Antifreeze is used all over the country and many areas on most jobs due to cold temps. Personally I would not have an air handler in the attic without antifreeze and a secondary drain pan in case of leaks.
Don't use more antifreeze than needed and never go over 50%. You will see fitting seepage that you did not have before. Do not use auto vents in the attic and make sure the pump is pumping up the supply pipe to the air handler.
 
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