Help!

CMadatMe

Is anyone aware of a nat gas condensing boiler  285K input that can vent 3" CPVC , 110' combined length, is 96% AFUE and has a 5 to1 turndown ratio?



Went on a job site visit today for a bid that is due. Those are the specs in the bid and they do not want the flue's touched. Flues were originally put together on the sidewalk, craned and dropped down the chimmney then cemented in..There are SIX of them. Job has old HydroTherm Multipulse boilers. At first was thinking Knights but that isn't happening with the vent issues..

 

Jean-David Beyer

Scary way to engineer a job.

I know of none, but that does not prove anything since I am not a contractor. I know of one that comes close, but requires 4" pipe.



But what if there are no boilers that meet that specification? The architect or engineer of the job should be able to name at least one boiler that meets their requirement, and my guess is that he cannot.



I wonder who gets to pay for the retrofit on the intake and exhaust system.

Tim McElwain

Chris, I have a lot of I an O manuals on all kinds of

equipment that may be able to handle those requirements. How big a rush on this as it will take some time to research?

CMadatMe

Have a Week

Tim,



I got the bid that was due on the 4th extended one week. These guys have no clue. I went there with one of my contractors as a favor. If I didn't open my mouth and press the issues this job was headed for trouble. This job is funded with state dollars and to pull information out of them is like pulling teeth. While driving to the job and reading the scope of the bid I already had many concerns.



It gets even better. Existing are 4 300,000 boilers thus the 1.2 in the spec.Walk in the boiler room, look at the piping and one can see they don't need it. The funds for this come from an Energy Efficiency program thus why they want 96%. I could care less about what's there and want to know if anyone did a heat loss of the building and have existing lengths, dimensions and types of emitters. Find out yup someone did but it wasn't divulged in the spec. Talking to the building management I find out they have been running on 3 of the boilers all heating season (1 is done) with no problems.



I then ask if anyone has gas bills over the past 2 years and low and behold yup. They have therms used for the past 2 years. They also have another two fo the same boilers doing domestic and want them replaced. Again find out been running on 1 with no problems. So I asked has anyone calculate the actual domestic demand on the bldg. Yup....



The point here is that they did the leg work but still just put it out to replace exactly the btu amount that is sitting in the basement. Building owner showed up well into the conversation and by the time I was finished he wasn't looking very happy. I am suppose to recevied on Monday, the actual heat loss that was done, the therms used in the last two years as well as the actuall domestic demand



My concern about types of boilers that are avail based on my original post was I don't think there are any and stated that there is no boiler that will meet the spec. If you look at the spec they are telling you Lochinvar Knight without specifically stating the actual boiler. By law they cannot spec a specific product mfg and you have to be good enough to figure it out. Which I of course I did because thats exactly what they wanted. Too bad it vents 4"  nice application for it.



Did I say the boiler room is real small which is also an issue.

Mark Eatherton

Try Lochinvar....

I think that sounds exactly like their boiler. I think it is called a 286 now, but is still 285K in. New number reflects new control logic.



ME



EDIT: Lochy won't cut it either. Requires 4" and limits 100' (which you said in your second post, DUH ME...)



Here's a link to their specs.



http://www.lochinvar.com/_linefiles/KBII-I-O%20Rev%20C.pdf



You MIGHT be able to convince their engineers to allow you to use 3", but the appliances will automatically be derated.



Camus might possibly work, but they are Canadian, if that matters. I remember something about all Federal dollars requiring either manufacturer or assembly in the US of A, but that was early on, and like the Health Care, people are probably asking for exemptions to this rule as well....



ME



ME

CMadatMe

Thanks Mark

I might just send them the venting and try that. Boilers shoot about 15' straight to a corner and then b-line straight up five stories.  

hot_rod

one of the mod con

brands had a de-rate formula for venting into old 2" HydroPulse vent systems, but the AHJs were frowning on it and they were concerned who would be responsible for any issues.



If it's worth doing....



hr

SpeyFitter

Try IBC

IBC's VFC 45-225 (45,000 to 225,000) Natural Gas Mod-con boiler can vent up to 240' on the exhaust and 240' on the intake if needed (240' each side), on 3" CPVC S636 ( CPVC S636 for the exhaust, you can use 3" ABS or PVC for the intake) with a 5' equivilent allowance for long sweep 90's and 8' foot equivilent allowance for short sweep 90's.

CMadatMe

HR

It would be worth the look to see what these boilers are actually delivering. They do have 4" vents coming off the boilers but were reduced to 3" after 24" or so. Plus one of them wasn't even working this past heating season and the building heated fine. Boiler room space is an issue to use smaller boilers unless we can get the load down to boilers that vent 3". The link is the building. Flue would be down on the right hand side of the bldg out the roof just at the 3rd car in.



There are no engineers to speak with. Project is being run by a Affordable Housing Conservency that provides monies to convert to high efficiency.



http://www.rupco.org/pm_stuyvesanthotel.html

CMadatMe

Scott

Tried that. They are not 96% AFUE. Don't meet the spec. One of the other issues I have. We are limited on boiler choice because of the 96%. I did propose that they give that a second look and bring it down to 95%...

Steamhead

Might be best to walk

this sounds like the typical no-win situation. Life's too short...............

CMadatMe

Not Yet

Trying to get them to do the right thing. Contract out having the existing vent system removed. Install a couple of 120 gal electrics for temp dhw. The demand is not large in the sense of multiple fixtures at the same time. It may not give them exactlt what they need but would get them buy for a week. I also asked them to provide the heat loss in the spec versus just the exisiting btu loads off the boiler tags. Same for domestic. Want the demand/load. There are 6 boilers there and based on the building running without any problems on 1 down heating boiler and 1 down DHW boiler we could combined dhw and heating into one bank of condensing boilers. Would make the footprint smaller and provide them the best bang for the buck. I think the bldg owner sees that is the best way to go. Will find out Monday am..

icesailor

Helped:

Nice solution to a complicated problem.

Done the way it should be done.

Congrats to a well thought out potential solution.

Tim McElwain

Yes Scott

that had entered my mind when Chris asked for a match up. I had looked up IBC this AM and agree with you. I would hope the 96 versus 95 is a small issue, but who knows.



The issue may also be that it is not a USA boiler which may cause more concerns.

scott markle_2

Interesting

Hope your able to influence this one in a positive direction.

scott markle_2

cemented in

The fact that those vents were cemented in sounds like trouble, to remove. Could it also be a bad practice by not permitting expansion and contraction.



If you could use indoor air you could halve your vent length. If removing the cemented vents is impossible maybe some kind of controlled outside air supply for the boiler room is an option.



I was curious about the vitdens cpvc venting requirements but couldn't find the specs. As I recall the 100 could do 80ft of 2''. If the restaurant could use a wall vent instantaneous maybe 6 120k boilers could do the trick?