I'm not sure if I'm in the right forum, but here is my question. I have very good commercial customer who owns a plastics factory, and commercial office space that hires us for everything. He hired me to hook up his outdoor wood fired boiler to his house and garage. House has in floor radiant, and domestic hot water will be run off this too, garage has in floor also. They installed everything and buried the pipe etc, he hired me to engineer it and make it work. That being said I contacted my wholesaler and along with our B&G rep, came up with a plan and diagram. It employs braze plate heat exchangers because I want to add glycol to the outdoor section. There is back up heat inside both structures, but outdoors if the fire goes out, or a pump fails, stuff is gonna freeze outside. My customer does not want glycol ...says the guy who sells the boiler said nobody puts glycol in them (????). We are in central New York. It gets cold here. Any thoughts or experience with these?