European style radiators

Christian Egli

The TRV is indifferent to the hot water temperature. Don't count on them to guarantee midly hot radiators. Afterall, TRV work great on steam too, and steam is usually beyond 212F.

They'll prevent the room from overheating, and indirectly, the radiator from overheating, but not under all circumstances.

For total safety do what J.C.A. and Mike T. suggest. I only made a post because I wanted to mention steam.

Jim Macdonald

European style radiators

I do a lot of high end residences and the european style rads have good client appeal. They seem to be rated at 180 AWT and I am concerned about skin against hot surfaces. Do TRV's hold the surface temp down as I am told or is it better to downrate them for lower temp water?

J.C.A._3

Why not both?

Go with bigger panels, lower water temps and TRV's. As long as the boiler will handle the return temps., it's a win/win all around. Chris

Mike T., Swampeast MO

In Europe, those "European style" radiators are almost always installed with TRVs.

TRVs will modulate the flow to keep the panel at just the temperature required to maintain the desired space temp.

Combine the TRVs with reset and the ONLY time you might have a 180° panel is in the absolutely coldest weather. The vast majority of the time the panels will be considerably cooler.

Of course you can always size the panels for design output at any desired AWT--they just get bigger the lower the average...

Generations of kids and people have lived with steam radiators that are well over 200° in temp. Kids might get one "oowie" but they learn immediately. Hard to consider a situation where you cannot rapidly remove yourself from contact with a horizontal surface.

Steve Ebels_3

Maximum water tem

In Euroland, max water temp is limited to 167*F IIRC. This however is due more to energy efficiency than safety issues. I have a couple jobs where the rads see 170-180 and they get hot but not to the point of burning. As a rule I try to design for 165-170 @ design temps. This means that for 90% of the heating season the rads will be 150 or less. Never had a complaint about surface temp.

Mike T., Swampeast MO

Thermostatic Radiator Valves \"Care\" About One Thing

TRVs regulate flow.

Flow determines the average temperature of the emitter.

The average temperature of the emitter when maintaining setpoint is ALL about how that emitter emits heat.

When called to raise space temp, TRVs allow maximum flow.

When called to lower space temp, TRVs allow minimum flow.

When called to maintain space temp, TRVs allow somewhere between minimum and maximum.

With steam, TRVs act like a variable vent.

R. Kalia_6

> The TRV is indifferent to the hot water

> temperature. Don't count on them to guarantee

> midly hot radiators. Afterall, TRV work great on

> steam too, and steam is usually beyond

> 212F.

>

> They'll prevent the room from

> overheating, and indirectly, the radiator from

> overheating, but not under all

> circumstances.

>

> For total safety do what J.C.A.

> and Mike T. suggest. I only made a post because I

> wanted to mention steam.

Rodney Summers

My steam thing got confused

Sorry about that, I meant TRVs on two pipe steam radiator. You're right TRV on one pipe do something different.

Then it is exactly like hot water set-ups.

RoosterBoy

Bruce

You could also put the rads on an injection system lower the supplys temps even further ...