Glycol question for radiant floor...

[SSpanky]

Is there a difference in quality of glycol? I just got a bid from a supplier and they want $40 a gallon when I can purchase some at local menards store for $20 per gallon.
I need 10 gallons so that's a big chunk of change.
Any help would be appreciated!
Mike.

 

[Jackfre]

Don't know what equipment you are running but some manuf require specific glycols. Best to do as they say. What percentage are you planning on running?

 

[SSpanky]

Percentage as in water reduction?
I have no clue yet, I'm still getting all my numbers together.

 

[brewchief]

Compare how much is needed to get to the same freeze protection point, some may take more then others.

There may be some recycled product out there, I've heard of it but never seen it, I would avoid it considering the quantity you need.

Last time I looked I think we were paying 75-80$ for a 5 gallon pail.

 

[pseudorealityx]

I've heard that quality appears to be a real variable with this stuff. I'm not sure why, or how, but I've heard it more than once.

 

[anthony666]

Is there a difference in quality of glycol? I just got a bid from a supplier and they want $40 a gallon when I can purchase some at local menards store for $20 per gallon.
I need 10 gallons so that's a big chunk of change.
Any help would be appreciated!
Mike.

propylene glycol is a fixed chemical substance, like oxygen or carbon dioxide etc etc .. most companies that sell it also stick a bunch of additives in it for rust prevention and to keep it in suspension and a host of other gimmicky reasons .. but pretty much its all the same when you get right down to the nitty gritty

one thing that springs to mind is the stuff from menards maybe premixed ??

whatever the case may be, glycol is very hard to pump and is terrible at heat transfer, use the bare minimum you need for freeze protection .. given the choice i'd rather run it more diluted than too stiff .. typically if there's a slab in the equation you have about three days before you need to worry about damage and your modern boiler will pump water through itself to keep from freezing

 

[BadgerBoilerMN]

A 25 % concentration is consider minimum to assure the right amount of inhibitor and general chemical stability. Only us a propylene glycol rated for closed hydronic heating systems noting the difference between burst and flow.

Unless you are installing a snow melted heated driveway, you need only concern yourself with burst, which should match the extreme mean for your area. I would rather install a backup heater, an alarm or smart stat like the Nest.

 

[mygarageone]

One other issue , there are 2 differant types of glycol , one for aluminum heat exchangers exclusively and the other for everything else.
There are very few boilers out there with aluminum exchangers , but there out there.

 

[Jackfre]

A 25 % concentration is consider minimum to assure the right amount of inhibitor and general chemical stability. Only us a propylene glycol rated for closed hydronic heating systems noting the difference between burst and flow.

Unless you are installing a snow melted heated driveway, you need only concern yourself with burst, which should match the extreme mean for your area. I would rather install a backup heater, an alarm or smart stat like the Nest.

Badger, are you saying that you would rather install the back-up heater, etc in lieu of the glycol? For most residential systems, other than snow melt, I try to avoid the glycol for cost, maintenance, flow reasons, etc.

 

[SSpanky]

Thanks for the replies guys. Ive read the labels closely, and I honestly dont see a difference in quality. Both labels say they have added "inhibitors".
Im certain its nothing more than a marketing ploy.
When I asked the boiler salesman, he got a little skittish and finally answered that the manufacturer wouldnt stand behind someone else's glycol for warranty purposes. bastids.
I guess I can understand though.
I do think 100% mark up in price difference does seem a little extreme,imo.

 

[Durasmack]

Good morning all!
I'm in the process of having a radiant heat system installed in my shop. My HVAC/Boiler guys does not recommend using glycol.
Badger stated as well "Unless you are installing a snow melted heated driveway, you need only concern yourself with burst, which should match the extreme mean for your area. I would rather install a backup heater, an alarm or smart stat like the Nest. "
Any other thoughts on this? I have a few buddies who have glycol in their radiant system and suggested that I do it as well.....
My HVAC guy said he would design a system for me as if he were installing this in his own home....
Any thoughts and or suggestions are appreciated.

 

[Brian_WK]

Good morning all!
I'm in the process of having a radiant heat system installed in my shop. My HVAC/Boiler guys does not recommend using glycol.
Badger stated as well "Unless you are installing a snow melted heated driveway, you need only concern yourself with burst, which should match the extreme mean for your area. I would rather install a backup heater, an alarm or smart stat like the Nest. "
Any other thoughts on this? I have a few buddies who have glycol in their radiant system and suggested that I do it as well.....
My HVAC guy said he would design a system for me as if he were installing this in his own home....
Any thoughts and or suggestions are appreciated.

First off on if you need glycol and percent a location would be needed.
Florida prolly not, Alaska definitly....
The stuff from the supplier might be 100% pure non diluted. The stuff at Menards might be premix 50/50.

Brian

 

[Durasmack]

I'm sorry. I just updated my profile. I'm in Chicagoland.... might be colder than (parts of) Alaska here in the winter!!!!
My HVAC guy is planning to just use water, no glycol. Looking for other expert opinions.

 

[ripperd]

When your power goes out during an ice storm for 2 days and your pumps stop working, you probably will wish you had glycol instead of a frozen pipe mess.

 

[Brian_WK]

When your power goes out during an ice storm for 2 days and your pumps stop working, you probably will wish you had glycol instead of a frozen pipe mess.

This

35% glycol will generally give you -50f burst cheap peace of mind.

Brian

 

[Durasmack]

OK. Thanks for the feedback.
I will have to figure out what his plan would be if that were to happen.
He's saying thru monitoring the system daily, if something were to happen, we would know.
His reasoning is the efficiency loss because of glycol's heat transfer issues.... at least that was my interpretation.

 

[Bondo]

Ayuh,.... I put radiant heat, with antifreeze, in my rental house a few years ago, just because I can't control the way a tenant controls the heat,...
'n it'd be one less thing to deal with, when a tenant takes flight in the middle of the winter,....

I can tell 'em, they gotta use the boiler system, but I can't stop 'em from shuttin' it off, 'n sittin' on an electric heater,...
Last guy had an electric fireplace that he loved,...
I told 'im he could turn the t-stats to whatever he wanted, so long as he left the boiler switch "On",....
The boiler heat loss alone can keep the domestic water pipes in the cellar from freezin',...

This house, with an oil boiler, 'n baseboard heat, I plumbed my homemade outdoor wood boiler right into the house's system, 'n use the oil boiler as the distribution point,...
It all runs on plain ole water outa the well,....

 

[Highbeam]

If the power goes out, in your home for long enough to freeze the radiant, you'd run a generator or crank up some form of heat to prevent the radiant from freezing. You also have plain water in the domestic plumbing to consider. I would assume that you're just not going to let it freeze and skip the antifreeze.

 

[Lassen Forge]

(1) Find out what kind of heat exchanger you have and match the glycol to the system - if your exchanger is aluminum, make sure you have aluminum-safe glycol.

(2) Find out the strength and match it to the specs. If there's a range, you usually match it to the lower spec for better heat transfer, or the higher if you get unusually cold winters (0f or below).

(3) DO NOT go to your local auto parts house and use auto anti-freeze.

We had a sub-slab heat system at one of our wash racks, they failed to read the book and then thought they'd save money by using the anti-freeze from the shop (they buy it in bulk) and made all 3 of the mistakes above. Twice. Getting the system repaired was a royal and expensive PITA - especially since we were going into sub-freezing nights at the time, so it had to be done "right now".

BTW - unless I lived somewhere it never froze, as in NEVER froze, there'd be no way I'd run bare water.

 

[ripperd]

If the power goes out, in your home for long enough to freeze the radiant, you'd run a generator or crank up some form of heat to prevent the radiant from freezing. You also have plain water in the domestic plumbing to consider. I would assume that you're just not going to let it freeze and skip the antifreeze.

I was assuming this was for a garage I guess. For a home, yes much less likely to go below freezing inside given that you have to live in it! Although the scenario still applies to cabin type places.

 

[Randy in Maine]

I don't use any in my garage/house radiant floor heat. Although we rarely lose power, I do own a generator (that has never been used).

 

[86turbodsl]

Here's a data point. I have(had) in floor radiant in my house attached garage. My HVAC guy had the system setup to circulate water only in it. No glycol and no heat exchanger. I had the main pump fail on a friday, and he couldn't get back out until Monday with a pump. Of course, it was the dead of winter and the garage temp got down to sub freezing. Long story short, i lost one of the two tube circuits in there. Since it's buried in concrete, there's no real fixing it.

On a house, you probably will be able to keep it from freezing, but in a garage, you may not get it fixed before you freeze it. Go with the glycol would be my recommendation.

 

[deckmonkey]

I would say glycol for sure. I had to run all new rads in a house where the infloor froze. Not very cheap to do and replace the boiler as well.

There is less heat transfer from glycol but really? You won't notice and the cost is probably pennies a month for energy use. Most infloor designs have flow rates/ delta t for glycol on them. This is similar to when my engineer friend told me we should run 1" pex for the infloor to keep the circ pump in the most efficient part of the pump curve.