Antifreeze for hydronic and boiler

[RHayes]

Have had a Heatmor up and running for 6 or 7 years virtually trouble free.  The loop from the boiler passes through two heat exchangers (a sidearm and a flat plate for domestic HW and in floor hydronic).  The in floor heat is a closed system.  

I enjoy the fairly long winters but feel like a slave to the system at times and might want to shut down to travel next winter.  

I was always under the impression that straight water was best for heat transfer and to just use it if possible but now want to get some freeze protection.  The boiler is 85 gallons and there is maybe 30 gallons in the piping.

Can anyone recommend a product I can start pricing and sourcing?

[gspren]

  I will need to go by memory since I'm on an RV trip several hundred miles from home but I believe it's Cyro Tek boiler anti freeze that I use, about a 50/50 ratio with water and it works well. We tend to go away at least once a month for a week or longer and since adding the antifreeze haven't noticed any loss in performance although others say you will. It's not cheap!

[RHayes]

Thanks.  I searched and found that from a few suppliers and now need to compare price/concentration.

[thecfarm]

RHayes.welcome to the forum.
I have the 400 model,the old style,takes a 54 inch stick. Put wood in,get heat out. Only trouble I had was had to replace the hoses to cool the door off.  ;D  That's not really a problem. I did have to redo where I clean out the ashes. Just on the back side.Had mine since 2007.

[RHayes]

Thanks  for the welcome.  I have the 100 with the 24" depth and sometimes use the 32" width. I have also done the door hoses, the bladder, and have on hand a spare blower and aquastats just in case.  

[hedgerow]

Welcome RHayes

I have a Garn boiler so I have around two thousand gallon water in it and its in a insulated shed so no freezing worries if I need to leave it for a while. I run four systems with five heat exchanger's and use the Cyro Tek brand of antifreeze on my secondary side of my heat exchanger's as they are exposed to the cold and could freeze. I have around 400 gallons in the four systems and its been in there for coming up ten years. I have in floor heat in a shop. My secondary systems are under pressure so I have pressure tanks also so no oxygen to the anti freeze. When I bought mine I shopped around a lot and there wasn't the 50/50 mix that their is now so you have to watch that also on the pricing. Back then I could buy wholesale but Menards ended up getting me the better price and it was in pails instead of barrels like the wholesaler had. 

[luap]

I run straight water but have thought about switching to an anti freeze solution. What I do now is turn the blower off on the stove but leave the circulating pump on. We were gone all of January this year and water temp was 55 deg when we returned.

[RHayes]

hedgerow, lucky for me I'm only about 30 gallons in the main floor slab and a small apartment above.  I have a number of locations I can force the antifreeze in and bleed off but still want to use full strength in case I don't get a complete transfer.  The boiler I have  is  Heatmor's smallest unit with 85 gallon tank and a semi closed arrangement with a bladder and loose fitting pop off ball.  It would be easy to just drain it down but I want the convenience of having it ready to go if I return in the dead of winter.  I'm thinking a 55 gal drum of full strength would be exactly what I need.  

luap, I have done exactly that on a few short occasions but worry about a power outage of a few days or more.  

[Rebarb]

I heat exclusively with hydronic but do travel quite often in the winter months.
Installed a heat exchanger in ductwork so while boiler pump is running in combination with heatpump, water temp never drops below 60*.
I've heard from several who do not recommended the use of antifreeze, mainly from an efficiency standpoint.

[RHayes]

The efficiency was my main concern.  I think raising the temperature might compensate though.  I run the water in the main concrete floor at about 85-90 deg. and the water in the tubes under the plywood second floor at about 110.  Longer pump cycles would not bother me a bit as long as the btu's get where they are going.

[hedgerow]

I don't think using antifreeze will hurt your efficiency. I run four heat exchanger's  on my system with boiler water on one side and antifreeze on the other and I check my Y strainers with a heat gun to see if they need cleaned on the water side and I don't see a big temp difference between the water side and the antifreeze side. Where your running floor heat you don't have to have the water real hot. Three of my systems are coils in furnace's so I have to have my boiler water hot or my furnaces run forever to maintain the heat in the house.