glycol or no glycol

i need advice on glycol. the boiler will be in the barn, 50ft away from the house with radaint floor heat in the barn, i plan on heating both the barn and the house with the boiler. 60' 1 inch thermo pex runs about 2-3ft deep between house and barn. basically im worried about the boiler failing for whatever reason and the pex under the slab freezing and my thermopex freezing. should this installation use a glycol mix or will these pipes stay warm enough for a long enough period that i would be able to for ex. fire up a generator and get the keystoker back online? and/or could my oil boiler be piped to back up the thermopex and barn floor automatically if for whatever reason keystoker came offline. thanks in advance. Paul

Hi Paul. Unless you leave home for long periods of time, I would skip the glycol. Glycol comes with its own set of issues. Cost, need to monitor chemistry, reduced heat transfer ability, etc. That Keystoker boiler is a lot of mass, and so is the slab...unless the wind is blowing through the barn you should have plenty of time to get a generator fired up.

Some of the guys were talking about this in a recent thread: Extended Shutdown Freeze Protection ?

If you wanted, you could heat the Keystoker/shop with the oil boiler as well.

For 100 reasons I never like the idea of antifreeze unless it's absolutely needed. I believe in using it only if you WILL freeze, not if you might freeze.

yes i deffinetly agree. the pad probably will take a couple days too cool down and i would imagine that thermo pex would take a while to cool down as well. just wanted to confirm i was making the right decision. thanks guys

hate to bring back this old post but as i come closer to firing the boiler for the first time, ive been talking to a couple of steam fitters on the job im on, and they all think im nuts for not running glycol and ive begun to second guess myself! lol. is this simply because this is what they are used to installing? the pad in the shop is pretty well insulated with 2'' foam under it and around the perimeter. i know you guys have said before i should be fine but what are the major drawbacks to running glycol? other than reduced heat transfer and the aggresiveness to leak and maintain inhibitor levels? it sounds more and more like for 300-400 it would be a pretty decent insurance that nothing could happen. please help!! thanks again
Paul

Lots ofindustrial applications use glycol, but there is not a good reason to use it in your case. Lots of people have done what you are planning without glycol, including many on this forum. If you are paranoid about the underground lines freezing, let the circulator run continuously...it is tough to freeze moving water.

Im more paranoid about a pump going down say on a sat night and not being able to get the proper replacement till monday short of leavin one on the shelf for back up but ive heard nothing but praise on b and g pumps.

A spare pump is cheaper than 50 gallons of glycol and yearly maintenance.

Maybe a better solution would be to add a small amount of glycol. Full strength is good protection down to 50 below or better. Adding enough to protect your system down to 10 or 20 degrees above zero would give you protection for almost all days and give you piece of mind. Doesn't take much to get there. Cost effective.

I like Scott's idea as well as all the others. GET and KEEP a spare pump on hand so you can quickly change one out if necessary. Moving water cannot freeze...and that is all that matters to you in an emergency!!!!!!! My $.02!

Make sure you use isolation flanges on your circulator(s). They make a midnight pump swap a 10 minute job.

Scott's idea is a good compromise.

Scottscoaled wrote:Maybe a better solution would be to add a small amount of glycol. Full strength is good protection down to 50 below or better. Adding enough to protect your system down to 10 or 20 degrees above zero would give you protection for almost all days and give you piece of mind. Doesn't take much to get there. Cost effective.

that is a real good idea, cost effective, and the small amount of glycol will help drive out the trapped micro bubbles in the fluid, actually increasing heat transfer. Full strength reduces heat transfer.

...and have the gaskets, etc hanging right there.....I assume most use iso-flanges, BUT not everyone plans ahead......like being smart enough to anti-seize the two mounting bolts years in advance so at 3 AM the change is a 5 minute affair.
We have dozens of -30 installs, but Scott is absolutely correct when he says to 'temper' the water with a solution. Cost effective and pro-active. I like his logic....not bad for 'the boy from Malta'!

thank you for the advice. now heres a stupid question since im just an electrician not a hvac guy. whats the best way to add the glycol? upside down hose bib? and can i just pour it in with a funnel? does it have to be pre-mixed or can i just dump 3 or 4 gallons in there. i estimate roughly my whole system is about 70-80 gallons? so maybe figure on a 10% mix and get 8 gallons? deffinetly going with spare pumps and gaskets and a nice generator tune up with plenty of fuel on hand. again cant thank you guys enough for the ideas its nice to have someone who already went through it or does it for a living to bounch ideas off of!

331camaro wrote:thank you for the advice. now heres a stupid question since im just an electrician not a hvac guy. whats the best way to add the glycol? upside down hose bib? and can i just pour it in with a funnel? does it have to be pre-mixed or can i just dump 3 or 4 gallons in there. i estimate roughly my whole system is about 70-80 gallons? so maybe figure on a 10% mix and get 8 gallons? deffinetly going with spare pumps and gaskets and a nice generator tune up with plenty of fuel on hand. again cant thank you guys enough for the ideas its nice to have someone who already went through it or does it for a living to bounch ideas off of!

Does it have to be pre-mixed - Yes and with high quality water. Best buy it premixed in 55 gallon drums. The suppliers will premix with purified water so no reaction between minerals in the water and the glycol occurs. If you don't and just dump slugs of glycol in the system, you may have slugs of glycol running around for a long time before it mixes. Also, any dead ends such as drain valve may never mix. You must be careful when adding it to ensure no water is trapped in the system that could create a potential freeze spot.

I like to use 30% propylene glycol. It will "burst proof" down to -10 deg. F. Burst proof will prevent the pipes from bursting but the liquid will still be slush, to hard to pump. This will protect a long time as it almost never drops below -10 in our area.

You must pump the glycol in the system. There are a variety of utility pumps you can buy that will work. Stay away from the cheap drill motor pumps. I use a washing machine hose that has a female hose thread coupling on each end for my final connection. Buy two 55 gallon drums for your system. 5 gallon pails are 3 to 4 times more expensive. Keep the spare on hand for future maintenance or replacement.

Glycol only if you must. It is rough on the system and you will find every leak you never knew you had when it cleans out the minerals that was plugging the leak.