help on modifying steam boiler to add hot water zone for addition in long island NY

henryxu

Hi, Heating gurus,
I am new here and need some expert suggestions to how to heat the 2 story addition (250 sqft ft each floor). Here is my current situation.
I have a gas steam boiler( it is burnham KIN4LNI-LE2 105000 BTU ) installed 4 years ago, currently is heating around 1300 sqft area. my steam heating system is one pipe system and have issues with two rooms are not hot ( even cold) at the far end of pipe. I tried to change different vent and still not work. sometimes one vent in the cold room is bleeding black water out before getting warm.

I have a plumber in the project and he is planing to tapping the current steam boiler to add water heating zone for the addition. since Feb he disappear and my general contractor also said he will not do this project even though i paid 90% of what he asked. the winter is coming and I need to have heating added for the addition at least.

Here are some options and please help to evelaute which one is best.
1. tapping steam boiler with additional water heating zone for addition. Also have someone to tune up the steam heating system to remove this bang bang noise in pipe and have two room warm at least. The problem for this modification i am not sure how many company can do this and how to maintain in the future. When this boiler is dead, have to replace one with company know how to do this.
2. modify this steam boiler to hot water boiler and have to repipe and add baseboard in all rooms. Current around 7 radiators in my house. not sure the cost. however, in future we can replace to hot water boiler if needed. Not sure if it is worthwhile to bring a new hot water in if it is only cost 2000-3000 more since convert steam boiler cost money too.
3. add a hot water boiler small enough to heat the 500sqft addition. not sure if it is possible to install a hot water boiler with large capacity but only use heat the addition, later can can use this water boiler for current house after changing steam heating to water heating if noise issue and heating issue can not be solved.
4. add combi system, how is the reliable for this and can the combi with large capcity run to heat the small addition with 500sqft too.

Sorry for long post. Thank you for suggestions. also welcome to PM me if you can work with plumbing license in Nassau county NY.

Jamie Hall

Wow. Well, you need a competent contractor, which you obviously don't and haven't had. Have you checked the "Find a contractor" link at the top of this page, or on the main page? There are several very good people who work in your area.

To go back to the issues. First, it isn't that hard to add a hot water section to a system basically fired by a steam boiler. However, though it isn't hard, it has to be done correctly. You will need a heat exchanger which gets its heat from the boiler, and then a separate pumped circuit to provide heat to the addition. It's done frequently.

Second, you mention two radiators which don't heat, and you mention banging. Both issues are probably related to pipes which aren't pitched correctly. Again, not hard to fix, but you need to find the pipes which are not correct and get them pitched properly.

Third, you very likely need a good deal of attention to overall venting of the system.

Fourth, I'd be willing to be good money -- if I were a betting man -- that the boiler hasn't been properly serviced in some time. Combustion numbers are probably off, pressure is probably set too high... etc.

Bottom line: you need a good steam heat contractor. Check that tab. They're out there.

henryxu

@Jamie Hall, thank you for suggestions. It seems that tapping into steam boiler is a good option as long as I can find a good guy.

Do you have any person recommend? I am not familiar with this forum and very new here

Jamie Hall

Right at the top of the messages pages -- this one -- there is a "click here" to Find a Contractor in your area. That will take you to a map, where you can select New York and it will bring up a list of contractors which will help.

henryxu

i already did and seems only two company in my area. thank you

Jamie Hall

So... try them both!

STEAM DOCTOR

As @Jamie Hall said, it's really not so difficult. The devil is in the details. Set up correctly, you will be nice and toasty. Incorrectly............You need someone who knows what they are doing and pays attention to detail. 

Big Ed_4

You need something like this

gennady

Or this

henryxu

That is complex seems to me. The issue is that do we need to have maintenance for this system every year?

Big Ed_4

The purpose is to separate the two different systems with a heat exchanger is to avoid maintenance (problems ) if the radiation is higher than the boilers water line .

Jamie Hall

henryxu said:

That is complex seems to me. The issue is that do we need to have maintenance for this system every year?

Yes and no. The system itself shouldn't need maintenance more than once every few years -- or even less often -- assuming it is set up properly as a closed system and doesn't leak much.

That is not to say that the boiler itself shouldn't be maintained yearly, in the usual way. It should. But that has nothing to do with the hot water loop.

mattmia2

the steam system will require more maintenance than the hot water loop.

henryxu

The purpose is to separate the two different systems with a heat exchanger is to avoid maintenance (problems ) if the radiation is higher than the boilers water line . What is the meaning of radiation higher than waterlie?

Jamie Hall

henryxu said:

The purpose is to separate the two different systems with a heat exchanger is to avoid maintenance (problems ) if the radiation is higher than the boilers water line . What is the meaning of radiation higher than waterlie?

The radiation is the radiators, baseboard, what have you. If it is higher in physical elevation than the water line in the boiler (seen on the gauge glass) It is remarkably difficult to get the air out of it and to keep it out, and you won't get circulation -- and therefore, no heat. So we make it its own closed circuit operating under its own pressure conditions.

ethicalpaul

It's remarkably difficult to get the air out and keep it out?

https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/

Jamie Hall

ethicalpaul said:

It's remarkably difficult to get the air out and keep it out?

https://heatinghelp.com/systems-help-center/how-to-run-a-hot-water-zone-off-a-steam-boiler/

Not if the hot water loop is properly done, with a heat exchanger and its own pressure tank and pump. If not -- if you are simply pumping boiler water around and up and down -- the problem is that if your hot water radiation is above the boiler water line, even when you get it primed, when the pump is off the radiation will be at a negative pressure. Depending on how high the radiation is and the water temperature, if the system is really tight you may get away with it. Better to do it right...

Big Ed_4

And just think even if system loop is tight if you add negative pressure from the system rise to hot steam condensate , what can happen ? .. Originally the condensate heating loop open to the steam boiler was used to heat the finished basement , bar and pool table room below the water line ... Later it was stretched above the water line where the issues increase ...

ethicalpaul

The article I linked talks about making sure the temperature in the loop stays well below boiling, even at the lower pressures in the loop.

And the article does recommend a separate hot water loop as the best way to go, but it also explains how the issues from not having one can be dealt with.

Is it that hard to have no leaks in a water loop? I'm asking honestly--I've never managed one so it's all a thought experiment for me so far.

dopey27177

Firstly a heat exchanger is not needed.

See the attachment.

This method is tried and true. Been in use for more than 50 years.


There may be no need to install the second floor H.W. zone.

Send pictures of the boiler piping and steam main & return.

Jake

Jamie Hall

OK. For reference. Without a heat exchanger:
If the water temperature is 120, the radiation can't be more than 30 feet above the water line in the boiler.
at 140, 26 feet
at 160, 23 feet
at 180, 16 feet
at 200, 7 feet
at 212 (when the boiler is making steam in the winter), 0 feet.

Or to put it another way, if your boiler is making steam in the winter, and your hot water loop with no heat exchanger fires up, you will get... no circulation. Very little, if any, heat.

ethicalpaul

The pressures and temperatures are definitely a concern, I agree. But I think your chart and statement aren't correct because with any loop, you would have a bypass that limits the temperature of the water going into the loop. You'd never send 212 degree water into the loop regardless of the season or state of the boiler.

I believe that is discussed clearly in the article from this site that I posted.

henryxu

it becomes so complex. So it will be safe to add heat exchange since I have both floor baseboard higher than boiler waterline(boiler in basement). So many details need to be paid attention. Thank you 

henryxu

Is my bolier 10200btu enough to heat up 1300sqft house (7 radiators)with adding hot water zone for 500sqft room( 2 baseboard)?

Jamie Hall

henryxu said:

Is my bolier 10200btu enough to heat up 1300sqft house (7 radiators)with adding hot water zone for 500sqft room( 2 baseboard)?

Impossible to know without knowing the heat loss of the house. Manual J. There are on-line calculators for that.

henryxu

Thank you  all for the helping.