New Homeowner Questions (insulation, venting, etc.)

Narf

I'm a new homeowner about to enter my first MA winter.  In doing so, I've started preparing the heating system and testing it out.  It's a one-pipe steam system - the boiler is about 20 years old but seems to be in good working order.  The pipes are probably original, and some of the near boiler piping has me thinking (even after reading Dan's book "We Got Steam Heat").  I started looking around when I turned the heat on the first time (after thoroughly flushing the boiler and low water cut off) and was welcomed with noisy, uneven heat.  I took a few pictures, so hopefully this will help with my questions.  I'm interested in any help/feedback on any parts of this post.



1 - It looks like I have a "dry" condensation return - does that make sense?  I have a 2.5" pipe running one direction, with all feeders, and a 1.5" pipe going opposite and sloped back to the boiler.



2 - Not much is insulated.  I plan to insulate the main, and all feeders I can access from within the basement.  Should I also insulate the condensation return?  I do have an unfinished portion of the basement that I would like to remain "livable" - but I have no problems insulating everything and then pulling some off if it stays too cold.

Do I really need to insulate the elbows and T's? 



3 - My venting was very bad to start, and I'd still call it bad.  The master bedroom radiator was the last to fill, and the living room right behind it.  I removed and cleaned or replaced those vents, and now they heat up faster but not ideal.  I'm planning to replace all vents in the system, since none are very good.  I currently have 2 main vents, one at the far end of the 2.5" main, and another at the end of the return near the boiler.  Is this sufficient?  I'm planning on putting #4s in the room with the thermostat, #5 everywhere else on the 1st floor, #6 everywhere upstairs, and #C in the master bedroom - does this also make sense?  Looking at Maid-o-mist vents.



4 - I am hoping that the insulation takes care of the water hammer, but I also think the section of pipe circled could have something to do with it - it slopes considerably down in the direction away from the boiler, but I believe it is supposed to be a condensation return.  Do I need to/how can I fix this?



5 - Also attached is a picture of my near boiler piping - is there anything wrong with this that would contribute to the water hammer?



6 - I have a picture of my master bedroom convector (other 2nd floor convector is the same, but it works fine) - is it common to have a "2 pipe" radiator on a one pipe system?  Does anything need to be done here to make it work better?  Could it contribute to my water hammer?  None of the downstairs convectors look like this. 



7 - Lastly, I've read that the programmable thermostats don't work so well with steam - is this true?  We have it set to drop about 5 degrees both during the day while away and during the night while sleeping.



Thanks in advance!

TomM

#4

i'll go for #4:

take off the union, and install a shorter nipple from the union to the elbow.  That should tilt the pipe in the proper direction.



also:

doesn't look like you have an equalizer on your near boiler piping, but that may be the pic angle.

-Tom in Conshohocken

Rod

Need more Pictures

Hi- Just took a quick look at your pictures and have some questions. Also could you take some more pictures of the piping around the boiler from different sides. Take them from farther back so as to get in the all the piping connected to the boiler. We can then blow up the pictures if we need more detail. 

Questions:

1. At what pressure does the pressure controller shut the boiler's burner off? I've attached a blow up of your boiler gauge- what is the reading on the gauge?

A residential steam boiler should operate at a pressures under 2 PSI.

2. From what I can see in the pictures you posted it would appear you don't have a header or an equalizer. Do you have a Hartford Loop? New pictures will help determine any problems in this area.



Answers to your questions.

1. Dry Returns vs Wet Returns.  This can be a bit of confusing terminology.  A dry return is the pipe that leads from the lower end of a steam main back to the boiler and is sloped so that the condensate in it flows to the boiler. When this pipe drops below an imaginary line that would be equal to the level of the water in the boiler, the pipe now becomes known as the "Wet Return"  Same Pipe, just called "Dry Return" above the waterline and "Wet Return" below it.

2. All the pipes that carry steam needs to be insulated. While not as important as insulating the steam pipes a lot of people insulate their return lines too. The elbows and fittings on the steam pipes should be insulated . There are special form fit pvc covered insulation fittings that makes this easy to do.

3. You need to get your main vents operating well first before doing your radiator vents.

    Are the main vents operation at the moment? This is an area where you will probably  want to increase your venting.

4. It would seem from the picture it is going the wrong way and the condensate is being trapped.  Not seeing the whole setup it's hard to advise you what to do.

5. Really can't tell too much without more pictures but it would seem you lack a header and equalizer which does a lot of dry out the steam produces by the boiler. "Wet Steam" is inefficient and causes all sorts of problems like water hammer and uneven steam distribution. You mentioned you changed you boiler water. Does the waterline in the sight glass bounce a lot when the boiler is running? Some bouncing is normal.

6. I don't think this is contributing to your problems .

7.  The general feeling is that using a setback of more than 5 degrees doesn't save fuel as it takes more fuel fuel to recover the temperature than just maintain it.  More important on a steam system is to have a thermostat on which you can set the cycles per hour. Normally they are set at "1" for steam.



With winter coming on I would highly recommend you take a look in the "Find a Contractor" section at the top of this page. Scroll down past the "Zip code" section to the "States" section and see what steams pros are located near you. There are some really good guys listed there for Massachusetts. I think it would be well worth your while to have one of them come out and look at your system and answer your questions. Later as you learn more about steam you can take over a lot of the normal maintenance,but at this point consulting a pro would put you way ahead.  If it hasn't already been done, you might have him clean your boiler and adjust the burner to its maximum efficiency. This should be done annually.

- Rod

Jamie Hall

I don't like

the bit of pipe in picture 4 at all, although without seeing the whole setup it's hard to say.



Thing to do is to think like water.  The question is, can it flow back to the boiler unimpeded?  If there any low spots -- whether an oddly connected pipe, like no. 4, or even a sag in a pipe, it's going to hammer, guaranteed.  So wander around in the basement, and figure out how any water in any pipe -- steam or return -- is going to make it back to the boiler.  (the exception is wet returns: wet returns can go up, down and sideways, so long as they stay wet, and if water in a steam main or dry return can make it to a wet return, that counts)  If it can't, you've got a problem...

Narf

More Pictures!

Tom, Rod -



Thanks for the replies! 



So here's the summary I've gathered:

1 - I have a dry return.

2 - I should insulate the main header and all feeders I can see.  I'll hold off on the return for now.

3 - I've read the rule of thumb is to have the main header vent in about 2 minutes.  Is there a good way to measure this?  I have one vent at the end of the main (about 40' of 2.5" pipe) and another vent at the end of the dry return by the boiler. 

4 - I should replace the nipple with a shorter one to slope that short section.  Any advice on how to do this?  I hear that the fittings crack when they're old.

5 - More discussion on this - pictures attached should show more detail.  I don't think anything about the near boiler piping is ideal (or logical) but it looks like there is some sort of loop.

6 - I will leave the convectors alone.

7 - Thermostat does not support a cycles setting... I've checked.  I can look into a new one (this is new, but I was naive).  I will also spend a few weeks this winter to see if we're saving anything by having the setback and adjust accordingly.



My pressuretrol is set to 0.5 cut in, differential of 2.  I tried setting it lower and the burner didn't stay on long enough.  After watching a cycle, the two pictures show the cut-in and cut-out.  Looks like it cuts in at 0.5 as it's supposed to, but the cut-out is still less than 2. 

Rod

Piping

Hi- I looked over the new photos. See if I'm correct, you have one main which I marked "A" in the picture and this connects to the Return marked "B".   The pipe marked "C" off the main steam riser is rather odd ball.  It would seem that it feeds steam to the pipe marked "E" and the condensate from "E" returns by way of "D".

 Where does "E" go? How long is it and how many radiators are on pipe "E"? How well are the radiators on "E" working?



Going back to Main "A", how many radiators are on this main? How are they working?

Main vents- Do you have any model numbers on the main vents?  You might check them and see how they are working. Don't reach up with your hand to check the vent as steam can give you a very bad burn. Use a strip of printer paper 1/2 wide and hold it close to the vent hole and that should give you an idea of how itis working and when steam reaches the vent ( the venting stops = no paper movement)

When the boiler is operating is there much up and down movement in the sight glass?

Excessive movement means your boiler needs skimming.

Your pressure adjustment is okay. That's probably about the lowest your going to get out of a pressuretrol. For finer/ lower adjustment you have to go to a Vaporstat.



Water Hammer- As Jamie mentioned you probably need to fix that "reverse" piping.

Have you checked you radiators to see they have the proper for slope? Also make sure that the inlet valve to each radiator is fully open.

- Rod

Narf

Piping

Rod -



You are correct about the piping.  "E" goes up to the master bedroom - only one radiator on this main.  Also, this is the only radiator that doesn't work so well.  It is one of the last to heat, and makes the most noise.  The room is on the second floor - I'd have to guess that it's about a 12'  vertical pipe.



Regarding "A" - there are 8 radiators on this main.  These all seem to work fairly well - some get hot faster than others, but about 20 minutes after a call for heat they are hot. 



I will check for vent numbers when I return tonight; they seem to be working OK but it may not be enough venting.  I will check with paper to see if the movement stops when that section of pipe heats up.



Regarding the sight, the activity seems "normal" from what I've read - I get about a 1/2" gentle up and down movement.



Is there a good way to fix that piping?  I feel that I'm fairly handy, but haven't done anything with the cast iron pipes.  I do not have inlet valves on any radiators, so they are wide open!



Zack

Rod

Radiators

Hi Zack-

   The relatively stable boiler water line is a good sign. I just noticed in your first post that you mentioned the downstairs radiators are different from the bedroom. How are they different? Not also fin tube?

- Rod

Narf

Radiators

Rod -



All radiators are fin-tube.  The downstairs units have a single pipe entering at the bottom left, and the radiator is sloped toward the entry point (makes sense).  The radiators upstairs have two pipes as shown in the picture.  I'm not sure what the purpose for the second pipe is...

Rod

Two pipe Fin tube

On the upstairs radiator the condensate flows out the second pipe and back to the inlet pipe.