4th floor radiator slow to heat

eappleton

Hi all,

We have a 4th floor radiator that is slow to heat. I wondering if my diagnosis and suggested solution make sense.

One of our apartments has been colder than other apartments for years now. It's on the top floor, exposed on two sides, and the roof is not insulated. It seems worse this year, but it may just be that everyone is home now, so we notice the issue more.

For background, apartments 3D and 4D are 3-room apartments, with a living room radiator, a bedroom radiator, and a riser in the kitchen.

4D living room rad


4D bedroom rad



Here is a diagram of the basement piping, but some of it is probably not quite right.



Existing vent A



Existing vent B



Existing vent C



To test the 3D and 4D radiators, we turned off the boiler manually for 90 minutes so that the radiators would cool down. Then we ran the boiler continuously for 30 minutes on manual. I started the boiler in the basement with the super then went to 4D to take photos. The resident of 3D reported out through text messages.

5 min - 196 degrees at boiler




8 min - vents hissing both apartments
9 min - 3D living room radiator heating up, bedroom radiator is not
9 min - 4D living room radiator 181F at valve, high temps throughout



9 min - 4D bedroom radiator 148 degrees at valve, 69 degrees at radiator



10 min - 4D bedroom radiator (bottom and vent side hot)




11 min - 3D living room and bedroom radiators are both scalding hot
11 min - 4D bedroom radiator




14 min - 4D bedroom radiator



16 min - 4D bedroom radiator




4D bedroom radiator - hot in places, but cool to the touch in others





Here are some things we were considering to address the issue:
- Additional tapped vent on riser where it attaches to 4D bedroom radiator?



- additional venting at D and E on the diagram?
D (hallway of basement):


E (in the super's bedroom):



- larger vents at B? We're not having issues on that side of the building, but the venting is less than other locations.


- larger radiator in 4D bedroom?

Thanks as always for your advice and counsel,
Eric

Jamie Hall

The cat is your Super? I like that...

But I'm curious about the temperature pictures. It looks as though you are getting steam to the radiator -- the pipe is nice and warm at the inlet -- but not very much. Two simple things I'd look at: is the vent on that radiator actually working? And is the valve really open? Either one could do that.

Then if you want to add a vent on the riser -- after checking the above -- there'd be no harm to that, and where you show it going is perfect.

STEVEusaPA

1st pic the radiator appears to be pitched the wrong way

eappleton

@Jamie Hall Thanks for the response. We replaced the air vent a week before the photos. I could air coming out, but slowly. Kind of whispering, intermittent. 

I tested the valve and it was all the way open, at least the handle was. Is there a way to check if the valve is actually open?

Thanks for the confirmation on the riser vent. How do you feel about the additional vents in the basement?

@STEVEusaPA Thanks, I noticed that and we're going to add shims. Interestingly, that radiator gets plenty hot and isn't making noise. 

Eric

neilc

what Steve said ^

eappleton

We would like to add a main vent or two to this pipe but I'm wondering what we have room for. The ceiling is only 3" above the pipe. Any recommendations?



Is it possible to fit a Gorton #2 at here at an angle? Maybe with a 45 degree elbow off of a 1/8" tap (including bushing and a nipple)?

Other suggestions?

nicholas bonham-carter

Is this a counterflow system, with no returns coming back?
If so, I would try to put all the main venting on the riser tops, as 4 floors of pipe hold quite a bit of air.
Once the steam gets to the basement vent locations, they will close, really before all the air has escaped.
The top floor valve bonnets can be removed, and tapped, the stems taken out, and then the largest main vents which will fit put on.
Thus the main venting remains open until steam has arrived at the top.
Slow down all the radiator vents with adjustable vents, so you don’t have the intermediate floors getting steam much sooner than the top floor, and roasting the occupants.—NBC

eappleton

@nicholas bonham-carter Yes, it's a counterflow system. One pipe.

If so, I would try to put all the main venting on the riser tops, as 4 floors of pipe hold quite a bit of air.
Once the steam gets to the basement vent locations, they will close, really before all the air has escaped.

That makes sense to me. We haven't done much to add venting on the risers. This particular riser ends at the radiator. There's no riser through the apartment for this radiator. (There is a riser in the kitchen for the living room radiator, which is heating up more quickly.)

The top floor valve bonnets can be removed, and tapped, the stems taken out, and then the largest main vents which will fit put on.

You mean the shut off valve for the top floor radiator, correct?

I don't think I've heard of this solution before. You mean remove this part of the valve? And add a tap to the bonnet?



You wouldn't have a photo or diagram of what this looks like after, would you?

This is what we were planning to do:



I do see the problem with this solution, since it only adds a Gorton D.