In floor heat sharing the glycol system with snow melt.

CanadaKeith

Hi Guys. I am a home inspector in Toronto, Ontario, Canada. Came across a house ( new construction) with glycol snowmelt system, and in floor heat for the basement was sharing the glycol. Both systems heated from one boiler, being a modern condensing boiler. Both systems operating at about 60 psi ( not reduced to 15 psi as I am accustomed to seeing. Two questions: 1) Any thoughts on risk with this approach? Is glycol fine for the in-floor basement heat? The two systems had separate control of course. 2) Any drawbacks of operating the system at a pressure closer to 60 psi rather than lower at 15 psi? and I'll throw in a 3rd) Are there any special boiler requirements for glycol systems.
Hope I did right by posting this as a new discussion. I searched but did not find any closely related posts.

hot_rod

Seems like a high pressure, most boilers have 30 psi relief, some can be upgraded to 45 psi if the manufacturer allow. 60 psi sounds like it might be a tankless water heater?
Bottom line, if all the components are listed for that pressure, it should be fine. Pumps, tube, fittings etc would be, not sure about the "boiler"

The expansion tank would need to be sized for glycol and pre-charged properly. Not connected to potable water, of course.

Derheatmeister

Normally we separate these systems from each other via a Heatexchanger for various reasons.
Some of these reasons are as the Following:
1. If a leak to the snowmelt should occur it could drain or airlock the entire home leaving the home without heat.
2. The entire homes glycol will have to match the snowmelt protection level which cost more $$.
3. The Piping system and the circulator pumps to the home MAY have to be altered/Designed to reflect the additional fluid viscosity... Again more labor, more Materials and more $$
4. Expansion Tanks will have to also upsized and will most likely have to be changed more frequently due to the heavier Glycol concentration.
5. System fluid maintenance will most likely cost more.

Why is the pressure set at 60 PSI ? Is the elevation change approx 120 feet

CanadaKeith

Appreciate all the comments. They are helpful. Yes it is a tankless water heater. The basement in-floor heat is installed as more of a marketing item rather than necessity. Two forced air furnaces providing the basic heat requirement. This is a common approach of infill builders here in Toronto. The hydronic system is often completed after municipal inspections are complete, and because it is not a mandatory part of the heat system it seems they escape inspection by any authority.

EBEBRATT-Ed

@CanadaKeith

I would just check and make sure the water heater is approved for use with glycol, Since it is designed for potable water I would doubt it was listed for glycol