View Full Version : antifreeze for radiant floor system


bobs409
01-06-2009, 07:33 AM
I was told to use only Propylene Glycol as the antifreeze for a radiant floor heat system and not to use automotive or RV antifreeze.

Question is, where does one buy this?

What are you guys using?


Thanks,

Bob

79firebird
01-06-2009, 08:33 AM
Last time i checked wallmart and canadian tire had it. its in the rv area. Its not cheap tho i think last time i got some for a friends rv it was like $8 a bottle

kbs2244
01-06-2009, 01:15 PM
Dis they say why?
Any good technical reason?
Some of those guys are "tree hugger" types and just don't like the "toxic" automotive stuff.

Ron Lombardo
01-06-2009, 06:43 PM
Bob,

Any local Plumbing & Heating Supplier would be happy to sell you CRYOTECH .. its a non toxic .. grade anitfreeze. Due to the fact that its being used for a residence and The EPA doesnt want US draining antifreeze down the sewer lines thats toxic. Also most of the time the heating system is tied into the Domestic water system and can potentially contaminate your drinking water ...if you dont use a backflow preventor .. CRYOTECH is RED ..the color indicates .. is NON TOXIC.

Ron

72VETTE454
01-07-2009, 12:27 AM
Radiantec first told me to use a propylene glycol boiler antifreeze, but at anywhere from $90 to $120 for 5 gallons, I said no thanks. I called them back to find out why propylene, they said in case of a spill or leak that it's safer for the environment. They also said Sierra antifreeze would also work. I had a hard time finding 30 gallons and was sick of driving around looking, so I went with standard ethylene glycol. Not that I don't care about the environment, but I'm not too concerned about a leak.

badgerboiler
01-07-2009, 05:28 AM
As Ron properly points out, in residential applications the chance of serious mistake is much greater than in commercial systems where ethylene glycol is more commonly used.

RV anti-freeze is not suitable for hydronic systems as it is not designed for the temperatures and components usually found in hydronic systems. Just like a vehicle the manufacturer has a spec. Inhibited propylene glycol made for hydronic heating systems is safe for people and equipment.

If you must use ethylene you should clearly mark the systems for the benefit of others.

BTW, I rarely use anti-freeze in systems unless they are unattended and even them prefer inexpensive temperature alarms as anti-freeze de-rates the output of equipment, resists heat transfer and costs more to pumps.

bobs409
01-07-2009, 05:36 AM
Well, I'm still confused on what to use. :confused:

This will be a closed system so no chance of contaminating any drinking water. I don't plan on dumping it anywhere so no harm there. I definetly want to use antifreeze so I have the option of turning the system off if I ever wanted to. (I'm in Pa so we have a good amount of cold weather)

Is regular automotive antifreeze safe to use then?

My system would probably have about 20-22 gallons so using the propylene glycol would be a bit costly for a 50% mix. If I had to use it, fine but if not, I'd rather put that money elsewhere.

Let the debate continue... :bounce:

kbs2244
01-07-2009, 12:12 PM
It sounds like there is no technical reason not to use automotive style.
It will not rot the tubes or ruin the seals in the pumps.
It will be toxic in case of a spill.
Your choice.

Ron Lombardo
01-07-2009, 05:43 PM
There numerous reasons to use antifreeze. It includes .. anti corrosion, lubricaion, and will prevent the system from freezing when not in use. The difference between auto and non toxic is just that ... keep in mind they sell a 50 / 50 auto premixed.

Basically the choice is yours ... here in Suburban NY .. they test the sewage at pumping stations around the area .. should they find chemicals coming from a resdiential area ..they will trace it an fine us .... should there be a spill ... the 500.00 worth of anitfreeze will be a drop int he bucket comapred toa six fugure cleanup.

Ron

Oldram__Newram
01-07-2009, 11:00 PM
For me I don't want to contaminate my own well that is about 60' away from my shed. I wanted to make sure everything was ok so for the first year nothing but water. I want to have to option to shut down part of the system, so eventually I will add non toxic antifreeze.

Torque1st
01-07-2009, 11:12 PM
AFAIK propylene glycol IS RV antifreeze. Most of the time it is sold as a 50/50 premix. Propylene glycol is non-toxic.
MSDS: http://www.paddocklabs.com/forms/msds/Propylene%20Glycol.pdf

Regular ethylene glycol automotive antifreeze is toxic to humans and animals but at our wastewater plant they say pour it into a toilet for disposal. Apparently the sewer bugs that digest the sewage love the stuff. Whenever A-freeze is brought to them for disposal they dump it into the system themselves.

bobs409
01-08-2009, 05:47 AM
Would this be the correct stuff? :headscrat :confused:

I found this on Tractor supply website for $3.99 a gallon.

Charles (in GA)
01-08-2009, 08:32 AM
Regular ethylene glycol automotive antifreeze is toxic to humans and animals but at our wastewater plant they say pour it into a toilet for disposal. Apparently the sewer bugs that digest the sewage love the stuff. Whenever A-freeze is brought to them for disposal they dump it into the system themselves.

I've heard basically the same thing in urban areas I've lived in.

Charles

RPH
01-08-2009, 12:22 PM
Read the side of the bottle. We just added RV to the system of a machine being shipped and it was propylene glycol . It is safer for all. Cheaper in the gallon jug at $4.00 per jug and 55 gallon drum was $6.00 per gallon.

'the epoxy floor guy'
01-08-2009, 04:12 PM
The stuff you purchase in the gallon jugs like the one in the pic are already diluted about 50/50. You should put that in with NO additional water.

If you are going to use this you should have a concentration of between 30% and 50%.

any more and you loose the conductivity properties of the fluid, any less and you have very little Freeze protection.

I agree with someone earlier. IF you have NO plans to allow the area that is heated to go below freezing there is IMHO little need for Anti freeze. It does effect your heating efficiency 'slightly'. As long as you install your pump VERTICALLY you should have little problem with lubrication.

Plus it is a MESS.

If you do use it TIP:

Using a 5 gallon bucket rig up a SUMP pump with a hose INTO your floor heat system. Pour in your water (and antifreeze if you use it) Let it mix in the bucket. DO NOT just put in ONE gallon water, ONE gallon antifreeze, it will take forever to mix, especially if you use a tankless boiler.

When filling put a hose on the 'opposite' side of where you are filling it and let it return back into the bucket. let this cycle for a while (30mins - 1hr) AFTER the system seems full. Make sure there is PLENTY of water in the pail to allow for air pockets to float to the top and the sump pump NOT suck them back into the system.

After you think it is FULL turn on the system pump and let it run ALSO. It will then probably stir up some more Air. Let run for another 30-60 mins.

PLUS, keep an eye on the level in the pail, as it goes down you want to keep refilling it.


when shutting things off: shut the valve on the hose you have returning into the pail FIRST. THEN with the pump running turn off the valve to the sump pump. THEN you can shut off the pump. This will keep your expansion tank full of water and give you a little buffer.

Torque1st
01-08-2009, 04:14 PM
I've heard basically the same thing in urban areas I've lived in.

Charles
Yeah, it would NOT be good to pour it into a home septic tank tho. Different systems, different methods.:thumbup:

UnionWelder
01-08-2009, 05:26 PM
ron is correct i would only use the stuff made for hydronic heating systems... I have seen other stuff used and lots of problems I saw a boiler which the homeowner used auto antifreeze and once the zone called for heat and the antifreeze hit the hot boiler shell it caused the antifreeze to jelly up and clog most of the boiler. I also have seen plenty of systems backflow thur the makeup water people shut water off and the rpz lets the boiler water fill the domestic water lines.

Torque1st
01-08-2009, 05:50 PM
ron is correct i would only use the stuff made for hydronic heating systems... I have seen other stuff used and lots of problems I saw a boiler which the homeowner used auto antifreeze and once the zone called for heat and the antifreeze hit the hot boiler shell it caused the antifreeze to jelly up and clog most of the boiler.
Sounds like the antifreeze was not mixed properly. ANY antifreeze will cause problems if not mixed properly.

I also have seen plenty of systems backflow thur the makeup water people shut water off and the rpz lets the boiler water fill the domestic water lines.
Sounds like a faulty check valve but nevertheless ethylene glycol should never be used where it can contaminate the domestic potable water supply.

Ron Lombardo
01-08-2009, 06:12 PM
As always the a product is introduced with certain properties for the application. In order to get the maximum output of your radiant system ... and save fuel cost ...as this is our goal here ..correct ... you should use the Antifreeze the Manufactuer specs.

I dont want my PEX tubing failing 4" below my concrete slab ... and when my boiler fails or pump fails and the manufacturer ...says no dice..what did you use RV or Auto anti freeze ... then the extra couple hundred buck .... was it worth it ....

... or we contaminate the family with a sweet tasting sustance that flow back thru a cross connection in the heating into the domestic water system and someone dies or get deathly ill ?

Its bad enough we learn about people dying from things we dont know ... why play with SOMETHING WE ALREADY KNOW and has been proven ? I take the easy road and learn from others mistakes... you dont have to tell me twice.

Ron

Torque1st
01-08-2009, 10:04 PM
RV & boiler antifreeze is Propylene Glycol and it is normally red and non-toxic. A person could actually drink small quantities, check the MSDS.

Automotive antifreeze is Ethylene glycol and mixtures are green and is very toxic to humans and animals.

Do not confuse RV antifreeze with the ordinary Ethylene Glycol automotive antifreeze.

Both pure Ethylene Glycol and pure Propylene Glycol have poor heat transfer characteristics which is why they are mixed with water for heat transfer applications.

BigChevy80
01-08-2009, 11:46 PM
I called them back to find out why propylene, they said in case of a spill or leak that it's safer for the environment.

Once again, the tree huggers are the bottom line... why am I not surprised? :rolleyes:

Torque1st
01-09-2009, 12:55 AM
Once again, the tree huggers are the bottom line... why am I not surprised? :rolleyes:
That is not tree huggers, it is just common sense.

Ron Lombardo
01-09-2009, 07:03 PM
RV & boiler antifreeze is Propylene Glycol ... my best guess and since I;m lazy to look this one up .. I would say the corrision inhibitors in the Boiler Antifreeze is increased and there might be other slight chemical charactersitics that are slightly added or increased to make it for the specific application.

Torque1st
01-09-2009, 09:23 PM
RV & boiler antifreeze is Propylene Glycol ... my best guess and since I;m lazy to look this one up .. I would say the corrision inhibitors in the Boiler Antifreeze is increased and there might be other slight chemical charactersitics that are slightly added or increased to make it for the specific application.
Probably correct, I used to be able to buy corrosion inhibitor additive concentrate for systems but I have not looked for it in many years. It may still be available at industrial supply houses. A pint of the stuff I used would probably serve for any normal residential heating boiler.

Burl
01-10-2009, 09:14 AM
I'm not doubting anyone's word here, but its funny that boiler and RV antifreeze would be the same stuff. Isn't RV antifreeze used in a non-circulating application, such a drain pipe P-traps, etc., and boiler antifreeze used in a circulating system, where you would need the lubricating properties for pumps? Shouldn't these be two different types?

BigChevy80
01-10-2009, 10:26 AM
That is not tree huggers, it is just common sense.

If you have common sense, you should be able to use regular antifreeze without issue. Just like it is used in millions of cars and trucks without issue.

Pardon my cynicism for the "environmental hysteria" crowd...

Torque1st
01-10-2009, 09:00 PM
I'm not doubting anyone's word here, but its funny that boiler and RV antifreeze would be the same stuff. Isn't RV antifreeze used in a non-circulating application, such a drain pipe P-traps, etc., and boiler antifreeze used in a circulating system, where you would need the lubricating properties for pumps? Shouldn't these be two different types?
I am not sure why you would say they needed to be different. It is just a non toxic mixture that happens to be used in two applications for it's freezing point depression properties. Just like regular ethylene glycol, propylene glycol is also slippery and provides lubrication properties for seals but then so does water. Water is used in many pumps for municipal and rural water systems as a pump "lubricant" and it works.

If you have common sense, you should be able to use regular antifreeze without issue. Just like it is used in millions of cars and trucks without issue.

Pardon my cynicism for the "environmental hysteria" crowd...

BTW- BigChevy80, we use regular ethylene glycol in cars and get away with it because it drips in small quantities from vehicles and large spills are diluted and flushed away quickly. We also do not drink our vehicle radiator fluid. Boiler systems are frequently tied in directly with potable water systems where leaks of ethylene glycol back into the water supply would be very hazardous to our health. Boiler systems could also leak over long periods into the soil around buildings, leaving a toxic waste "pool" in the soil.

mmg440
01-11-2009, 08:28 PM
The way I see it Ethylene glycol is fine for a radiant system or other boiler systems. I can see everyone does not agree. Common sense should be used when anything considered toxic is used. I would never use it in a system heating used to heat potable water with a single wall heat exchanger! this could prove fatal if seepage occurred. But they use it to deice air planes and it can and will break down when it enters the environment. I would not personly want to intentionally leak it into the environment. Many areas it would be breaking multiple laws. Not would I like to see it get into a waterway (such as some cheap boat winterization being dropped into the water with car antifreeze still in it). But I would think It would be able break down before it contaminated a well as long as you don't just drain your system completely down onto the ground. I would think the system would stop functioning from a air lock and a leak would be investigated if you lost to much fluid.

"What happens to ethylene glycol when it enters the environment?

The primary source of ethylene glycol in the environment is from run-off at airports where is used in de-icing agents for runways and airplanes. Ethylene glycol can also enter the environment through the disposal of products that contain it.
Ethylene glycol in air will break down in about 10 days.
Ethylene glycol in water and in soil will breakdown within several days to a few weeks. "

source
http://www.atsdr.cdc.gov/tfacts96.html