Near Boiler Piping

ammachine390

Hello,
I just received the Lost Art of Steam Heating and Greening Steam in the mail the other day and have been reading. Anyway, looking at all of the diagrams I am nearly 100% sure the near boiler piping is not ideal. It appears to me that there is no hartford loop or equalizer.

The house was built in 1928 and was originally equipped with a coal boiler that was replaced in 2005 by the current boiler, which is a Peerless 63-03s. I am pretty convinced that the heating contractor who did the installation did not really understand steam heat. In addition to the strange piping, the pressuretrol is set to cut in at 2 psi, and cut out at 3 psi.

The large main on top goes to the 2nd floor and the smaller pipe goes to the first floor. At the end of the 2nd floor run, the pipe drops back down and attached to the condensate return.

What do you guys think of this piping?

I've also included a very basic drawing of how the entire system is laid out in the house.

BobC

If you look at the piping diagram in the installation manual you will see how it is supposed to be piped and it's nothing like you have right now. There is no header and no equalizer, the pressure should not be higher that 1.5PSI and it would probably be better off a lot lower than that..

How well does the boiler run, does it heat evenly, quietly, and economically?

Bob

MarkS

The absence of a Hartford loop is a safety concern. It's purpose is to keep the water from running out of the boiler if a return pipe springs a leak. Do you have a functional low water cutoff, and have you tested it? With the current piping, that's your only defense against a potentially dangerous situation.

To improve steam distribution performance, you should consider adding another vent(s) at the end of the "lower" main on the left side of your drawing.

ammachine390

I was reading through the installation manual for the boiler just the other day and saw that it was off.

I just haven't found any diagrams that explain how to pipe the system where the first floor and second floor are on their own main.

I find it strange that the one main is so large, while the first floor one is so small, it does eventually, roughly 15 feet down, turn into a 2 inch pipe.

I also find it strange that with the whole first floor connected to only the condensate return, that we get any heat on the first floor at all.

To answer your question Bob, the whole system works great as it is right now. No water hammer, no banging pipes, no spitting vents. Only thing that seemed off was that when the boiler would start, the vents on the radiators would whistle ever so slightly, however, that was when the main vent was completely inoperable, the Gorton 2 was just installed in May, so I don't know if the radiators still whistle since the heat hasn't been used since its been installed. Fairly even heating throughout the whole house. I don't know what would be considered economical. We live in the Chicago area, and our January bill, which was 29 days long, we used 298.85 therms of gas. The average temp in that period was 22 degrees, and there were 1281 heating degree days in that period. House is insulated on first floor and in the atic, more than half of the original windows have been replaced and the house is about 1400 sq ft.


My thoughts are that the small pipe that goes to first floor, should also be connected to the pipes on the top of the boiler. Correct?

Fred

Wow, that boiler is plumbed so wrong, I don't know how it could heat as well as you say??? There needs to be a header (horizontal) off of that riser going up from the boiler. Then, both mains (if there are actually 2 mains) would tie into that header. You need an equalizer, off of the end of the new header, after the mains and you most definately need a Hartford loop for the sake of safety. I can't see the Low Water Cut-off (LWCO) but I'm guessing it is a McDonnell Miller #67 and that your Pressuretrol is mounted on top of it. You must make sure that LWCO is working properly, especially until you can get a Hartford Loop installed. Are you sure the first floor isn't tied somewhere into the larger main that also feeds the second floor? What you think is a small main is obviously only a return for condensate. There is no way the first floor radiators would heat with the configuration you describe. Do the radiators on the first and second floor have just one supply pipe on each radiator or is there a pipe on each end of the radiators? Also, the pressuretrol should be set at about .5 PSI Cut-in and no more than 1.5PSI Cut-Out.

ammachine390

Hatterasguy said:

Since the gas also makes hot water and is used for cooking, we need to subtract a certain amount of therms for that. Typical for a family of three would be about 40 therms per month. This gives you approx. 260 therms to heat the building.

The result is 14.5 BTU/degree day/ ft.²

This is on the high side of the usage curve and would typically indicate an older house with limited or no insulation, or a house that is heated to well above 70°F (common on steam systems).

Our base gas usage for house is about 30 therms per month.

Thermostat is set to 70 from 6 am to noon, 67 from noon til 5 pm, 70 again from 5 til 1 am, and 69 from 1 am to 6 am.

I've done that calculation myself without subtracting the base gas for cooking and ended up with about 22 btu/degree/ft^2, just didn't know what was considered efficient.

BobC

Is it possible the installer used the skim tapping to feed one of the steam mains?

Having looked at the pics more closely I can now see the skim port is not being used to supply steam to the main. Are you sure threr isn't a connection between the first and send floor mains. Do you know if one of the mains is counterflow?

Bob

ammachine390

Fred said:

Wow, that boiler is plumbed so wrong, I don't know how it could heat as well as you say??? There needs to be a header (horizontal) off of that riser going up from the boiler. Then, both mains (if there are actually 2 mains) would tie into that header. You need an equalizer, off of the end of the new header, after the mains and you most definately need a Hartford loop for the sake of safety. I can't see the Low Water Cut-off (LWCO) but I'm guessing it is a McDonnell Miller #67 and that your Pressuretrol is mounted on top of it. You must make sure that LWCO is working properly, especially until you can get a Hartford Loop installed. Are you sure the first floor isn't tied somewhere into the larger main that also feeds the second floor? What you think is a small main is obviously only a return for condensate. There is no way the first floor radiators would heat with the configuration you describe. Do the radiators on the first and second floor have just one supply pipe on each radiator or is there a pipe on each end of the radiators? Also, the pressuretrol should be set at about .5 PSI Cut-in and no more than 1.5PSI Cut-Out.

Hi Fred,

Thanks for your response, it prompted me to go look at everything again. The basement is mostly finished and a lot of the pipes aren't easily viewable. The one section with the small pipe its totally inaccessable as of right now unfortunately. I also thought it was very peculiar that a main would be so small. However, my diagram was wrong, please disregard it. The large main that you can see in the photo, does indeed branch off to the 2nd floor but also continues to the first floor. It is very hard for me to see it, but it looks as if the small pipe is a condensate pipe for maybe just the first radiator. Not sure, it's strange and currently hard to see. I will try to shove my phone up there and get a photo.

I've also included a pic of the side of the boiler showing the LWCO. It does function, and we do keep a close watch on the water level.

ammachine390

Here's a couple pics of where those 2 pipes go. The large main branches off and goes to the second floor, and then continues, then there is a branch that goes to the first floor radiator. Then continues and turns to the left through the rest of the basement, which you can't see in the pics.

That small condensate return is piped into the main just after the branch for the first floor radiator.

BobC

Since you found the connection between the first and second floor mains we should check to make sure everything is sloped properly, can you verify that the supply piping is all sloped back towards the boiler or the boiler return? If the piping slopes towards the return it is a parallel return system, if it slopes back towards the boiler it is a counterflow system. It is possible that one floor is one and the other is different.

Once you know the supply piping is correct you should get a proper Hartford loop installed and then a proper header that can supply the system properly.

Bob

Abracadabra

Is that a gas cock i see as the shutoff to the water feeder?

Fred

The large main that you can see in the photo, does indeed branch off to the 2nd floor but also continues to the first floor. It is very hard for me to see it, but it looks as if the small pipe is a condensate pipe for maybe just the first radiator.

That makes a lot more sense. At a minimum, You should have a Hartford loop installed and a short header with an equalizer installed on the end of the header (opposite where the boiler riser ties into the new header. That will make for a much dryer steam which is what you want.

JUGHNE

How about some radiator pictures, some upstairs and some downstairs?

ammachine390

I spent the past few days insulating the steam main in the basement. I also installed a 0-3 psi gauge on the boiler.

Afterwards I ran a test to see what kind of crazy pressure I was building, especially since the presuretrol has been set at cut in of 2 and cut out of 3 for the past 10 years. I am aware that is wrong, I just wanted to see what it had been operating at.

After 12 minutes of operation, the steam main just off the riser was hot, and at 22 minutes of operation the entire main was hot all the way to the main vent. I shut it off at 35 minutes, and all radiators in the house at this time were very hot. Throughout the entire duration, the pressure guage never read higher than 0.05 psi. Does all of this seem normal? And if not, is it a result of my wrong near boiler piping?

Fred

That pressure is great but it sounds like you may need some additional venting at the end of that Main. It shouldn't take 22 minutes to heat a Main unless there is an issue pushing the air out ahead of the steam. Even a good size main should vent and heat in maybe 5 minutes, give or take a minute or two, depending on the length of the main.

ChrisJ

Once my boiler starts steaming (this takes around 15 to 20 minutes from an ice cold start) I often get steam to my radiators in around 1 minute @ as low as 0.25" WC or 0.01 PSI. I originally had a 0-3 PSI gauge on my system but it never moved.

Typically in the winter, including time to get the water boiling I'm looking at 3 minutes from the time the thermostat calls for heat to get steam to the radiators.

This is with what is considered an undersized boiler (10% pickup factor) but the boiler is piped well and I have properly insulated mains and plenty of venting on both the mains and radiators.

10 minutes to get steam to the end of the mains is unacceptable.

JStar

10 minutes is our cut-off for acceptable. Some bigger size mains just create too much condensate and the steam will never make it to the end any faster.

ChrisJ

JStar said:

10 minutes is our cut-off for acceptable. Some bigger size mains just create too much condensate and the steam will never make it to the end any faster.

I'd assume that's on some of the huge jobs you've done with 100+ foot long mains though, no?

What do you feel the typical residential system should be capable of? My longest main is 2", 29' and carries around 53,350 btu vented via 5 Gorton #1s.


I still don't see anything obsessive about this drawing.

JStar

That time limit applies to all systems, no matter how large or long the mains. Some systems just can't beat that mark, even with the main vents removed.

Abracadabra

ammachine390 said:

Throughout the entire duration, the pressure guage never read higher than 0.05 psi. Does all of this seem normal? And if not, is it a result of my wrong near boiler piping?

.05 reading on a 0-3 psi gauge is usually just a single line.. Not sure how accurate those gauges are at a pressure that low... Accuracy for most gauges like that would be .05, so your pressure sounds like it could be 0-.1 psi.. Did you use a pigtail on the gauge?

vaporvac

I'm confused: is it taking 10minutes or 22minutes to reach the end of mains? I'm understanding 10 minutes to the first take-off and 22 minutes to the end-of-mains vent.

Fred

I agree @vaporvac, I read it as 22 minutes to reach the end of the main and as I said earlier, in this string, that's too long. More venting please.

ammachine390

It took 10 minutes for the steam to travel from the beginning to the end of the main. The first 12 minutes was the boiler heating up the water from a dead cold start.

The 0-3 psi gauge is mounted on a pigtail (which is not clogged).

Steam main in the basement only is roughly 12 feet long with 2.5 inch pipe, then 45 feet long with 2 inch pipe, then 4 feet long with 1.5 inch pipe. The one for the second floor I cannot measure, but is probably pretty close in length to the main in the basement when including the vertical components to bring it to the 2nd floor.

Fred

Got it. 10 minutes isn't great but it's not horrible either. I have a main that is about 15ft of 4" pipe and then about 70ft of 2.5" pipe. It takes about 5 minutes to heat from the Header to the end of the main.

MarkS

ChrisJ said:

I still don't see anything obsessive about this drawing.

It's not to scale.

ChrisJ

MarkS said:

ChrisJ said:

I still don't see anything obsessive about this drawing.

It's not to scale.

Prove it.

RomanGK_26986764589

I have a 65ft main. It heats in about 3-4 min. Don't know if it is too long.

hvacfreak2

RomanGK_26986764589 said:

I have a 65ft main. It heats in about 3-4 min. Don't know if it is too long.

That sounds pretty good. With insulation and or venting you may be able to reduce that time.

Fred

3 to 4 minutes for a 65 ft. main is really good.