SSSSS Steam heat res boiler and asbestos
My sister is thinking of replacing her Steam heat boiler, has gotten several bids three I think.
She is in NJ I am in Idaho so she has been reviewing them with me. contractors are telling her with steam she can do no better then about 82% efficiency. Is this true, it seem she can not convert easily to hot water since even though two pipes are going into the radiators the supply and return lead to one main pipe.
In doing this she is going from oil to gas.
Also, visitable pipes are asbestos wrapped as well as the boiler jacket, which leads to another question particular to N,J. She has been told that now in NJ when one sells a house if asbestos is present it must be removed before the sale, is that true? YOU NJ flippers out there must know the answer to that one.
Wallyo
Replies
>>She has been told that now in NJ when one sells a house if asbestos is present it must be removed before the sale,
Unlikely as a matter of law, but it's possible that banks may have their own guideline/rules.
Even there, there was asbestos in many building materials used before the 70's, it's hard to imagine any sort of cut and dried rule.
See, e.g., :http://www.epa.gov/asbestos/pubs/ashome.html#3
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May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
"We Live" http://www.youtube.com/watch?v=7kuBgh0VCqI&mode=related&search
And Annie Ross's "Twisted" http://www.youtube.com/watch?v=8lqivrCIRGo&mode=related&search=
Being born there all I can say is sometimes NJ has some weird laws, one of the few states that requires a buyer and seller to both have lawyers at the sale of a house in addition to the agents and the inspectors and bankers. Not that having a lawyer is a bad thing to have at a home purchase it just gets me that it is required who came up with that one the lawyers!She was told by several persons (all of whom were involved with the bid that it is required by law that a sale can not that place if asbestos is present) I am just trying to verify it with some one not selling the removal.I will look into the wall site that you and reinvent recommended.Wallyo
Post your Q here as well in the section called the Wall:
http://heatinghelp.com/
A lot of experts on steam heat hang out there and she could probably find a pro in her area to give her the straight talk on weather she should switch to FHW
>>contractors are telling her with steam she can do no better then about 82% efficiency. Is this true, it seem she can not convert easily to hot water since even though two pipes are going into the radiators the supply and return lead to one main pipe.
Don't know about efficiencies of steam boilers, but I do know that the published efficiency figures are theoretical, not actual.
And she should compare the potential cost savings of going to a higher, "90+" against the increased cost of such a system and the conversion costs.
The web site usually deemed the most authoritative on steam heat is called "the wall" at http://www.heatinghelp.com/homeowners.cfm
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May your whole life become a response to the truth that you've always been loved, you are loved and you always will be loved" Rob Bell, Nooma, "Bullhorn"
"We Live" http://www.youtube.com/watch?v=7kuBgh0VCqI&mode=related&search
And Annie Ross's "Twisted" http://www.youtube.com/watch?v=8lqivrCIRGo&mode=related&search=
I have done the same thing twice: switched from oil to gas boiler for steam heat; once in Hoboken, once in CT.
I didn't worry too much about the (theoretical) numbers - any new boiler was going to be a million times better than the old one!
Generally speaking, asbestos pipe insulation is much better not disturbed. I have wrapped mine in heavy duty aluminum foil. But I'm planning to die in this house, so I'm not worried about resale...
Kate I agree with you on leaving the asbestos alone only dealing with what needs to be removed ie the boiler and pipes in the area that they need access to. But the contractors are telling her that the law has changed and a seller needs to remove all visiable asbestos. The supply return pipe is wrap and maybe some legs to the radiators.On a side note she is in Bloomfield, we all grew up in Bayonne.Wallyo
It has been a long time since I lived in NJ, so I wouldn't be the authority on asbestos - I just wanted her to know that I've had a good experience changing from oil to nat. gas & keeping the steam system. Love my radiators!
She loves her radiators too. She has duct work for central AC, I raised the point that she could do gas forced air, put the furnance in the attic where the ac is, and it would be cheaper. You would think I told her to sell the houise.Wallyo
You can't sit on the ductwork & eat ice cream, or leave your slippers on the duct for toasty toes...
82% is the combustion efficiency. System efficiency is different. Even a mod con boiler may only be 85% depending on the system.
Hopefully someone at the wall will be close by.
She is in NJ I am in Idaho so she has been reviewing them with me. contractors are telling her with steam she can do no better then about 82% efficiency
Yes, I believe this is true. Steam heat has a lot of nice things going for it (very comfortable heat, simplicity of the system), but efficiency is not one of them. You can crank it up a few more % points with a motorized damper, but this is about the limit.
She is going to copy or scan the bids and get them to me I will check if any include a motorized damper. Thanks for bringing that up.Wallyo
Squeezing that last 15% efficiency out of natural gas fired equipment requires condensation of the moisture out of the flue gas. This occurs starting somewhere below 140F. Since a steam boiler is operating at the boiling point of water, 212F, there is no chance of getting any condensation to wring the last of the energy out of the flue gas.A high efficiency hot water boiler won't always get the rated 95 to 97% either. It depends on a low operating temperature, or at least a low return water temperature to operating in the "condensing mode". At least the one I have is designed to operate with an outlet temperature up to 180 or 190F but once the return water (boiler inlet) temperature gets close to 140F, it ceases to condense the water vapor in the flue gas and operates with a similar efficiency to a standard boiler, about 80%Even if one could rework the plumbing for the radiators to change the system to hot water, I would not be at all surprised that the system would have to operate too hot to gain much efficiency much of the time as presumably a steam system would have been built with smaller radiators because it operates at a higher temperature. It is possible that if they system was over sized when it was installed and if significant improvements have been made to the insulation and airtightness, that it could operate a low enough temperature to have a significant increase in efficiency.In addition to changing the piping which would require asbestos removal before it could begin, the radiators would need to be drilled and treaded of bleeder valves at the top of the radiator and the air vents removed and plugged.
KURTThanks for the input you have explained the physics of why steam cannot have as high an AFU as hot water concisely and to the point. For the reasons you pointed out and others, we have ruled out an conversion, I just broght up the issue in case some one said "Why don't you convert it" But thanks to those of you who recommended the wall I have learned something. There is an old one pipe hot water system called a diverter tee system it stopped being used in the fifties. It used special tees with either scoops or funnel like devices in them
( the tees are still made). To install one was real heavy on calculations, took a lot of planning but installation was easier since one pipe. If you were doing tract houses it was great, design it once and put the same in every house save on labor and pipe.How do you tell a diverter tee hot water and a steam system apart I e-mailed the guru himself Dan Holohan and he was kind enough to get back to me this morning this is what he said:"It could have been either, Wally. If it's a diverter-tee system, there will
be a circulator near the boiler. If it's steam, there will be a gauge glass
on the boiler. "For anyone wanting more education on Diverter Tee check out this link it was written by Don; http://www.heatinghelp.com/heating_howcome3.cfm.Wallyo
Edited 3/7/2008 11:24 am ET by wallyo