RFH Strategy Question

Jed_2

I am wondering, with today's state of mixing control strategies, if anyone is still installing conventional Supply/Return boiler headers; using 3-way TMV's as mixing devices, for multi-temp, multi zone systems. I am continually faced with Plumbing&Heating contractors(these guys are basically Plumbers, not Hydronic Technicians), who are joined at the hip with there builders, defiant about the cheapest Radiant System money can't buy. One of our customers told me he installs Joist Space tubing and sets the temp at 125deg.-Period, on all jobs. No regard for heat loss, floor covering, or anything. Plates? Forget it, it isn't in the budget. Berlin Wall before Ronald Reagan. I'm not Ron Reagan. I have developed the attitude that Zone Header TMV's is NOT Radiant heat, just low temp convective transference. And to top it all off, they use high volume pin oil fired boilers with indirect water heaters, cold start. Modulating controls- too much money.

Just Venting!

Jed

Boilerpro

Modulating controls can be cheaper than TMV's..

with a little thought put into the piping layout. Inexpensive manually fixed three way valves adjusted to provide a set mixture of hot supply and cold return water to a rad floor with an outdoor reset control on the whole system provides outdoor reset for all the zones. AS the system supply water warms up in cold werather, the mixed supply water to each zone warms up, and vice versa in cold weather. I had a 1952 rad slab system where I adjusted the formerly powered mix valves (they were proportional valves tied to the zone thermostats) to a fixed position and the boiler water was only modulated from 140 to 180 A retired engineer said the heating had never been that comfortable and steady.

Boilerpro

Jed_2

Now that's being creative

I like it. My challenge is to get my Plumbing & Heating contractor Customers to see it, not only as a much more effective system, but cost effective as well. I am making some progress with a few. Just keep plugin away, I guess. It took Siggy's Essay to show me the Proportional strategy. I kept thinking the three way valves in his drawings were tmv's. Duuuhhh. I now am showing manual 3-ways when down mixing is required. Two of my Customers are going to use it on upcoming jobs. Presently, I sell Taco Expandable Relays, with PC705's. So far so good. I just believe everyone should be using more advanced strategies, not just TMV's.

Thanks for the input.

Jed