Recessed radiator in wall - 2 pipe steam

veteransteamhvac

2 pipe vapor steam system here. At some point the previous homeowners had the 2 radiators in the living room recessed into the walls, the only two like this (of 9 convectors). The one in the pictures presented heats poorly so I'm working on curing the problem. Over time the recessed radiator has settled enough to cause poor heating and banging.

Looking at the situation I'm confronted with the possibility of what to do. Do I fix the situation and move it back into the cubby hole or just abandon that and put the convector back in the room. The picture shows it is located just next to the front door. This happens to be the northwest corner of the 1st floor, definitely the coldest part of the home. The house is 3 course brick with plaster walls. If I put the radiator back in there a lot of heat is being lost out the front wall. You can also see that there's a very nice cover that is basically 10 guage steel! I don't have any aesthetic issues with radiators so I'm leaning towards moving it back into the room.

My boiler is just about right sized to undersized but I definitely have hot spots and cold spots in the house, this being a cold spot. Would I be better off pulling it out or insulating the cubby with reflective material and putting it back in there?

Motorapido

My house is one-pipe steam with recessed radiators on the ground floor and non-recessed upstairs. Although I wasn't having problems with my recessed radiators, I didn't like the idea of losing lots of heat through the outside walls where these recessed radiators are located. Mine is a100 year old brick house, plaster interior walls, in Central Pennsylvania -- zone 5 or 6 I think. I could feel air infiltration around the recessed radiators, coming from the core of the wall and probably some working its way in from outside. I removed the radiators, carefully air sealed up all gaps inside the recessed area with caulk, and then attached reflectix silver bubble foam insulation, with the seams taped with Tyvek tape. I would have preferred to have put 2 inch foam insulation panels with foil facing in the space, but I had room only for the very thin reflectix. Reflectix is lousy insulation, but it works great as a radiant heat reflector. Also, as a plastic foil product, it makes a vapor barrier. The bulk of the benefit for me came from sealing up the air leaks in the recesses. Maybe I save 50 cents per heating season as a result of the reflectix insulating r value and maybe $1 per heating season from the radiant reflection value of the reflectix. But the air sealing was certainly very helpful. Reflectix is inexpensive and you won't need much. Instead of reflectix, use solid foam panels if you can fit them, but reflectix if you cannot. You don't want insulation directly contacting the back side of the radiator, since that would kill the convective air flow through the gaps between the radiator tubes. Make sure you have an inch or more space behind the radiator after you do whatever you do, so you have proper air flow around the radiator tubes.

veteransteamhvac

Motorapido said:

... Make sure you have an inch or more space behind the radiator after you do whatever you do, so you have proper air flow around the radiator tubes.

Do you feel this has made a significant difference? I'm very close to just pulling the convectors back into the room.

Motorapido

You attribute the poor heating of this radiator to settling of the floor and you mention water hammer. To answer your question, I don't think that the air leak sealing I did in my radiator recessed nooks and the reflectix made a significant difference. I did it because I was going through the process of sealing air leaks throughout the house. I'm sure the total combined improvement of all the little air leak sealing I did all over the house added up to fuel savings, but the work on just one recessed radiator nook probably created just a very tiny improvement in itself. Back to you mentioning settling and banging. Why not seal up the air leaks, add insulation if you have the space, and then when you re-install the radiator, carefully make sure it is properly pitched to drain its condensate. That should fix the banging. Also, check that the air vent on the radiator is working, and if you have a balancing issue that is causing the radiator to under-heat, change the vent on this radiator and probably several others. You will probably need a slightly faster vent on this radiator, and maybe slower vents on others, to balance them.

veteransteamhvac

I've actually spent the weekend working in the recessed area and pulling out the piping that was added to push the radiator into the alcove. Although the work on the alcove is quite nice the rennovators didn't do the low pressure steam system any favors. To get the radiator into the alcove they simply took the supply and return lines off at their connections and added elbows and about 10" of lateral pipe towards the exterior of the house. This had a fairly large effect on the pitch of the return pipe as it pushed it down about 4" underneath the floor boards. The pitch of the supply pipe was not affected as much. However, with the return full of water the steam really had no reason to move into this radiator.

The simplest solution right now is to insulate and cover up the alcove and just reattach the radiator in its original spot. I don't even need to cut any pipes!

ethicalpaul

Inserting my opinion here: Insulate and cover up those holes and put the radiators back proudly in your rooms. You will get so much more radiant heat and so much less loss.

EdTheHeaterMan

ethicalpaul said:

Inserting my opinion here: Insulate and cover up those holes and put the radiators back proudly in your rooms. You will get so much more radiant heat and so much less loss.

I'm Proud to agree with Paul

Yours Truly,
Mr.Ed

veteransteamhvac

ethicalpaul said:

Inserting my opinion here: Insulate and cover up those holes and put the radiators back proudly in your rooms. You will get so much more radiant heat and so much less loss.

Thanks, I am on the way to doing exactly that. I have some insulation and already cut some 2x4s and drywall to cover up the alcove for the rest of the winter. The person in me who starts projects but never finishes them thinks he might actually do a bit of carpentry work and turn the alcove into usable built in shelves or something like that. But that won't be happening now. Right now, the plan is just get the radiator moved into place and hooked up again.