Second Opinion on Radiator

Triguy

I am converting a steam radiator system to hot water and just wanted to confirm that the radiators in the picture can actually be converted to hot water.

Charlie from wmass

In theory they can be as they

are attached across the top. I have found wall hungs to be the most likely to leak even on steam pressure. Why are you converting? Steam for oil can be 86% efficient with no electric for pumping the heat or controls to start and stop the pump. Gas you can get 84% depending on the system.

Brad White

Check out

that relatively small branch feed and control valve size. Looks like 1/2" pipe- rare to see it that small. Reminds me of Gerry Gill's Iron Fireman system, but this one may have been a vapor or vacuum system. May be one of those rare gems.

Charlie from wmass

Brad look again!

I would bet it is a cobbed in control valve. I think it is 3/4" iron bushed down. People wonder why the controls do not help. They do not get full size valves is why it does not work.

Brad White

Aye, that it may be....

If cobbled in, it must have been 40 years or more ago, my guess. Vintage pneumatics. But you probably are right.

Charlie from wmass

I find if it looks rare it is

most likely cobbled.

Brad White

But

cobbling is not rare!



At least in these parts.

Mark Eatherton

Vent boss casting...

You want to be sure there is a place to drill and tap for a manual bleed vent. It is usually a small spot, very near the top of the radiators fluid passage ways, that you can drill and tap for a 1/8" manual bleeder vent.



Before you go to all that trouble, you should pressure test the radiator to make certain it is not already Swiss cheesed. Not more than around 15 PSI.



ME

Triguy

Thanks

For all the input.  The radiators have vent screws so we are going to attempt to use those.  It is a pretty old system.  The boilers that are serving the system are Kewanne with a stamp of early 1900 in it.  I will make sure we pressure test the system for sure.  Is there anyohter gotchas I should take note of for converting the system. 

We are changing it over for energy reasons.  I know we could have a long debate about that.

Charlie from wmass

For energy reasons

Sorry for the pun but they do not hold water. A new properly installed steam boiler will do you more good.

Gordan

Are the radiators still going to have sufficient output?

Given that they're sized for steam, not hot water. Unless there has been quite a reduction in heat loss through insulation/weatherization, I'd be inclined to worry.

Triguy

Output

They have added insulation and windows during past project. 

Gordan

Heat loss calcs will tell, either way.

It's quite a drop from steam to hot water.