Stage 2 ????? Jamie

Mark Hunt

the second stage will be set a few degrees lower than the primary and will drop out before that happens.

If the two systems are not interfaced, overshoot would be more of a concern than not letting the radiant do its job.

There are a bunch of btu's waiting to come out of the floor and they do not care if the T-stat is satified or not, they are going to come out.

Zoning the air system can reduce the odds of this happening, but you are right about it being a concern.

Mark H

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Jamie Pompetti

What do

What do you guys do when you install hydro-air as your second stage of a radiant heating system? Aren't you affraid that the air will satisfy the t-stat and not let the radiant do the job?

Just food for thought!

Wayco Wayne

I am

about to do a job where this is a concern. I'm just going to use the B terminal on a honeywell t87f to initiate the radiant floor so when the customer turn to heat the radiant floor will come be enabled. After that I just plan to ride the curve and let the hydroair cycle on the merc bulb. The curve will be controlled by a taco exp board with the Taco 705 variable injection control. I'll let you know if I encounter any problems. WW

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hot_rod

fuzzy logic

As I understand it some of the stats out there will keep looking at what is going on with the temperatures and still allow the floor to pulse in even after the second stage calls on. So the first stage floor still gets attention even after the second stage is on.

Could be I heard this from Danfoss and Honeywell, maybe tekmar, anyone have the scoop on this? Bill "Honeywell", Hydronics Mike, or Team Danfoss?

hot rod

Boilerpro_2

I think

that most two stage stats keep the first stage running when the second stage kicks in. I've used tje Honeywell Chronotherm and a tekmar 512, and both work this way. Once the first stage can't keep up, the second stage begins to cycle.

Boilerpro