Cost of propylene glycol

DCContrarian

I look after three houses in New England that are closed up for the winter. The heating system s are filled with a propylene glycol mixture to protect against freezing. Plus I fill the traps in all of the drains to protect them.

Lately it seems like the price of glycol has gone through the roof, I can't find it pure anywhere for less than $30/gallon and the 50/50 premix is about $25/gallon which works out quite a bit more expensive. I recently had to drain down the heating system in one of the houses for service and just replacing the glycol looks like it's going to be around $500.

What are people doing? Are there alternatives or should I just suck it up?

ethicalpaul

What do you do with the domestic water pipes?

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1803162#Comment_1803162

Blow them out with compressed air.

ethicalpaul

Could you similarly drain/blow down the heating system and just keep it filled with regular water?

Or, alternatively, when you have to drain the heating system for service, can you drain it into a plastic drum instead of down the drain then pump it back in?

Instead of putting it in the toilet, you can pump out the toilet and sink traps with a little hand pump. Do traps burst when they freeze?

Just some random ideas, I don't know if they will work for you or not, good luck!

DCContrarian

Filling and draining the heating system tends to kick up a lot of muck. Having it sit full of air tends to invite corrosion. So I believe — with great conviction, but scanty real evidence — that it's better for it to sit full of water than empty. There's also the factor that if you leave it full, if someone wants to visit during the inter it's just a matter of flipping a switch to get it going again.

How I got in this situation: normally I leave the makeup water off. The system in this house developed a slow leak. Someone, not me, noticed the radiators needed bleeding and opened the makeup water. By the time I got involved pretty much all of the glycol had been lost. It could have been disastrous.

DCContrarian

"Instead of putting it in the toilet, you can pump out the toilet trap with a little hand pump."

I empty the tank and bowl of the toilets with a shop-vac. Then I put a quart of antifreeze in the bowl to seal the trap so the house doesn't fill with sewer gas.

ethicalpaul

Sounds like you have it pretty dialed in…your only really expensive event seems like it was when some knucklehead messed with your system. I'll be interested to see others' suggestions!

WMno57

Paul said: Instead of putting it in the toilet, you can pump out the toilet and
sink traps with a little hand pump. Do traps burst when they freeze?

Yes, traps burst when they freeze. Been there, done that, and have the tee shirt. The toilet is in a landfill.

Don't leave the traps dry. You don't want sewer gas in the house.

RV antifreeze can be used for traps, and it's cheaper than PG. PG, EG, and alcohols all break down in both septic and municipal sewer systems. The additives and corrosion inhibitors might not.

Used automotive antifreeze from older vehicles had heavy metals from the soldered brass radiators. That is where the no antifreeze down the drain rule came from. Around 30 years ago, automotive radiators switched to aluminum cores and plastic tanks. No heavy metals.

If you are DIYing a coolant change on a Prius, put it down the drain. EG kills pets, so don't leave in in the gutter. If you are Jiffy Lube, or draining an entire hydronic heating system, check into your recycling options.

hot_rod

Certainly use RV fluid in trap and plumbing, it is cheaper than inhibited hydronic PG. Although some is methanol based.

Also buying 55 gallon drum should save $$. buy straight glycol and mix to 35- 40%

35- 40% should be adequate for a home burst protection with hydronic PG. 50% i over-kill

pecmsg

https://forum.heatinghelp.com/discussion/197208/cost-of-propylene-glycol

McDonalds had seen cost increases 159% over 5 years.
costs go up!

Pass it on.

EBEBRATT-Ed

We always use 30-33% glycol. Winter design is 0 here never an issue. And that was outside piping. Inside a house even with no heat is a bit warmer.

Jamie Hall

All the glycols are synthesized from natural gas. Natural gas supplies are down, and costs are up…

hot_rod

https://forum.heatinghelp.com/discussion/comment/1803176#Comment_1803176

I thought glycols were "cracked" from a barrel of crude oil?

Bio glycols tend to be a bit less $$, made from soybean, canola and corn base product, no petroleum.

Caleffi solar fluid is a corn product.

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1803171#Comment_1803171

I haven't really kept track, but it seems to me that ten years ago glycol was around $10/gallon. Now it's triple that. Way more than inflation.

PDTech

$3.29 / Gallon at our local Menards.

DCContrarian

Mostly denatured ethanol. Not suitable for heating systems.

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1803183#Comment_1803183

Keep in mind that inflation — as published — covers a wide range of cost indexes. Fuel is only one, and a rather minor one at that. Tripling the fuel price in ten years, most of that in the last three — at least where I live — is quite real (fuel oil, gasoline, LP)

hot_rod

https://forum.heatinghelp.com/discussion/comment/1803191#Comment_1803191

I suggested this for his plumbing freeze protection that he mentioned. Plus I fill the traps in all of the drains to protect them.

Also that it is available a a PG or alcohol based product.

JakeCK

I second the rv antifreeze for traps and toilets. Its what I use for my rv.( I both blow out my water lines with my air compressor and then pump premixed rv antifreeze into the system, it only takes about a gallon and a half if that. I also drain down the water heater and isolate it with the bypass.)

It sucks that you had to drain down the whole system and now need to refill. Buy the drum as suggested and mix to the percentage recommended for burst protection in your climate.

Is it possible to add isolation valves to the system before you refill so the next time it needs service you aren't having to drain the entire system?

Derheatmeister

We would "Stop the bleeding" first by a pressure testing each zone of the system in oder to locate the leak and repair it !

Yes…Using RV Antifreeze in the traps will save some $$.

BTW: Using Deionized water vs. Regular tap or well water to delute the Glycol will in not compromise the inhibitors in the glycol and it will last longer.

We like to use a Glycol feeder vs a feedvalve.

We like Fernox Alphi 11 .

Hope this helps.

GroundUp

As others have said, stick with RV antifreeze for the drains and traps. That Freeze Kontr'l that Bob mentioned makes a 95/5 variety at 95% PG and you'd be more than fine with a 2:1 mixture for a mothballed house in your climate- 50% is way beyond overkill. A 5 gallon bucket of that 95/5 is about $35/G so your final cost would be approximately $12/G.