Radiator in unfinished attic

Shahrdad

One of my friends was touring an 1892 mansion in St. Louis, and he noticed these radiators in the attic. They look at lot like radiators used in indirect radiant heating systems, but from what I know, these were always placed in the basement, which would then allow the hot air to rise. Why would similar radiators be in an unfinished attic?

EBEBRATT-Ed

good question. who knows what they were originally trying to do. Those look like indirect heathers to me.

bburd

The only thing that comes to mind is offsetting the heat loss through the roof. I have seen this in places like pre-war museum buildings with large skylights.

Steamhead

Was there ductwork coming to these units? They may have been to cause a natural draft in a ventilation system.

JUGHNE

Get the snow off of the roof?

psb75

An antique form of "ice dam removal"?

DanHolohan

There may have be an open expansion tank in that attic space. The exposed radiator would have kept it from freezing. 

Shahrdad

DanHolohan said:

There may have be an open expansion tank in that attic space. The exposed radiator would have kept it from freezing. 

There was also a big metal-lined wooden tank with a float in the attic. It looks like a big box rather than those cylindrical copper expansion tanks I've seen in your books. My guess about that this tank was that it was for domestic water use, since water pressure in STL at the time was very unpredictable. It would make sense that the radiator was there too keep that tank (and maybe even an expansion tank) from freezing. I suppose it could also have helped keep the roof warm and melt the snow.

DanHolohan

Yes. Domestic water. That’s why the radiator is there. 

psb75

Our 1860's farmhouse in Michigan had a large domestic water tank in the attic that was filled by a ram-pump placed in a flowing stream 1/4 mile away. Tank maintained a constant outflow. The house also had cisterns in the cellar that were filled by the wooden rain gutters for soft water. Hand pumps at the sinks for cistern water.

kmj

Guessing: preventing ice dams

rberq

A guess -- Some coal-fired boilers had (still have) a "dump zone" to absorb excess heat, because the mass of burning coal can not be turned off instantly like an oil or gas flame. Normally no water at all circulates in the dump zone, but the system is there in an emergency, as an alternative to get rid of heat before resorting to pressure-release venting. So these radiators may be a holdover from that type of system???

Adk1guy

DanHolohan said:

Yes. Domestic water. That’s why the radiator is there. 

That makes sense, is that not a steam vent upper left in pic indicating a steam system? I love the simple hefty pipe supports.

stm212

They actually look like sections of a cast iron boiler. The nubs on the face would be to increase surface area as flue gas passed between sections.

pecmsg

kmj said:

Guessing: preventing ice dams

It will create ice dam's!

mvickers

Storing the water that high as kinetic system pressure + aux heating

jumper

I don't think so but those radiators,when empty, make an excellent expansion tank. Again I don't think so but they can be a condenser/air vent for steam heat.

ethicalpaul

pecmsg said:

kmj said:

Guessing: preventing ice dams

It will create ice dam's!

Not if it keeps it so warm up there that the snow immediately melts!

clammy

I have heard tale that durning the depression in a near by early 1900 community that after the stock market crash that money was such a concern that in fact the wealthy had the servants finished 3 floor living quarters removed to lower the property taxes .supposly they would completely unassembly the old slate roofs ,rafters everything remove the outside walls and put the roof back on . I was not only told this by a old timer but had been in a few attics where in fact not only radiators but also sinks ,tunes and toilets where stick in place no wall but tile still on the floor. I guess labor was beyond cheap and every body needed to work . Peace and good luck clammy

gassyman

I am with PECMSG on this one, ice dams are created when heat migrates through the roof and melt the snow which then runs down to the overhang portion of the roof which has no such heat, and freezes there. Other than ice-melt cables, the cure for ice dams is more insulation in the attic to prevent melting on the roof... until ambient temperature allows it to melt off of the eaves as well.
As to the radiators, I trust Dan.

jumper

gassyman said:

I am with PECMSG on this one, ice dams are created when heat migrates through the roof and melt the snow which then runs down to the overhang portion of the roof which has no such heat, and freezes there. Other than ice-melt cables, the cure for ice dams is more insulation in the attic to prevent melting on the roof... until ambient temperature allows it to melt off of the eaves as well.
As to the radiators, I trust Dan.

How about sheet metal to conduct heat from warm part of roof to overhang? One problem with unheated attic is too much snow buildup.

CLamb

Perhaps it is to discourage penguins from nesting in the attic.