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heater99
09-10-2009, 07:57 PM
I have seen 2 types of Hydronic radiant heat systems.
"closed looped" and "shared water".

1. "closed looped" Water circulates from boiler to thepex coils and back under little or no pressure. The heat system is Isolated from the domestic hot water.

2. "shared water" In this case the system is conected to a city water sorce and is held around 60 lbs pressure while being cycled through the boiler the pex coils. The same water is used for laundry showers and other domestic use. Shared systems eliminate the need for separate boilers. Seen at: http://www.youtube.com/watch?v=2E4cFaZYgLU&feature=related

My question is: Which system would you prefer and why?
beenthere
09-10-2009, 08:24 PM
Glycol reduces heat transfer.Why would you be adding glycol.
heaterman
09-11-2009, 11:38 AM
I too am confused by the question.
heater99
09-11-2009, 03:06 PM
Glycol reduces heat transfer.Why would you be adding glycol.

Not sure what it is for, but I have seen it used in radiant heat systems. http://www.youtube.com/watch?v=vPfaKGKqq9s
heaterman
09-11-2009, 03:18 PM
The only time we use glycol is when there is the danger of freezing due to long periods of uninhabited structures. As far as normal radiant as opposed to potable combination systems, we don't use potable systems.
beenthere
09-11-2009, 05:52 PM
Glycol is an antifreeze.

Only needed if the lines will be subject to freezing temps.
sprintmj19
09-11-2009, 07:20 PM
Some municipalities do not allow domestic water to be circulated through a heating system...MAJOR code violation.

How did the guy in the video protect the domestic water from freezing?
heater99
09-16-2009, 01:43 PM
How did the guy in the video protect the domestic water from freezing?

Perhaps he is in a region where freezing is not a concern.
gassyplumber
09-28-2009, 01:56 PM
Open systems are a BAD idea, do you want stagnant floor (heating) water coming out of your faucet. Also new water all the time will lead to corrosion/mineral deposits. I have seen a few wirsbo manifolds with cartridges that are fubared.

You want a heating system with a closed system and backflow protection. Aim for a NTI combi unit, or a condensing boiler like a Viessman Vitodens, or NTI trinity piped into an indirect fired tank such as a Vitocell or Weil McLain plus 40 tank.

A boiler pressure relief as 30 psi, so you can't operate a boiler safely at 60psi only a hot water tank with a 15psi relief