Expose riser to heat bathroom?

cnjamros

In a remodel by the previous owner, they added a bathroom to the back of the house. The only heat they put in was a small wall-mounted Broan heater. It's quite loud and seems like a waste of energy to run it often, especially in the coldest part of the season.

In one wall of this bathroom, adjoining the original house, is a 1-1/4 riser going to the upper floor.

I've been thinking of how to use this to bring some heat to the bathroom. Adding a radiator would be cost-prohibitive right now.

If I put a grille between the studs at the floor and another at the ceiling and used the entire cavity where the steam pipe passes through as, essentially, a large convector, would I get a measurable amount of heat into the room?

See the photo for a sketch of what I am thinking.

Appreciate anyone's thoughts.

bburd

What size is the steam riser? If it is insulated, you would need to open the wall cavity and remove the insulation to get a meaningful amount of heat out of it.

EBEBRATT-Ed

Even though the pipe is hot it will not give off that much heat.You could replace a section of the pipe with commercial steel fin tube but that would probably cost more than a radiator. Search a junk yard for a used radiator and install that.

bburd

You would get meaningful heat out of that if you open up the wall cavity and allow the exposed pipe to radiate directly into the space. This is how most bathrooms in New York City apartment buildings with steam heat are kept warm. A bare 2" steam riser in the corner is more than enough to keep them toasty, though typically they only have one wall and perhaps the ceiling exposed to the weather.

That is why I asked about the pipe size. It's easy to calculate how much heat you would get once you know that.

BobC

If this addition has 3 walls exposed to the weather thy scheme won't work because the heat loss is probably just to high. A radiator is your best bet.

Bob

Hap_Hazzard

BobC said:

If this addition has 3 walls exposed to the weather thy scheme won't work because the heat loss is probably just to high. A radiator is your best bet.

Bob

And even if it did work, it's not going to stay hot for long between cycles, and chances are, it's going to be between cycles whenever nature calls.

Unless you're extremely lucky, you won't find a radiator of the size and shape you need at a junkyard, but there's a company called Castrads that makes brand new, very attractive cast iron radiators in a wide variety of styles, shapes and sizes, free-standing or wall-hung. I own two of them myself. Since this is probably going to be a summertime project, you can take your time and wait until they have a sale. Visit their website or reach out to @Nick_Castrads for more information.

If I were you I'd run a new riser up through the floor. With an existing riser that close you shouldn't have too much trouble piping in another one for your new radiator.