Connected load calculation - a must for an NYC master plumber?

NRW

Hi experts:



I had an NYC master plumber replace my old Weil McClain boiler 3 years ago. Too bad I hadn't discovered this site and done my research then, because I would've run 10 miles in the other direction if I knew then what I know now. He didn't do a connected load calculation, and basically said that he estimated a certain square footage of steam per floor and that's how he arrived at the size of the new boiler - which is definitely bigger than the old one, and almost twice as big as what I need. So I have uneven heat distribution and short-cycling, and, not surprisingly, pissed off tenants.

Anyway, long story short, the guy won't make it right, even though I've had two heating specialists examine the problem and both have concluded that the boiler is too big for my system. I'm suing him to recover the cost of replacing the thing, and I'm trying to find published guidelines or standards for NYC master plumbers which instruct them to perform a connected load calculation when sizing a boiler. Does such a thing exist? If so where would I find it? One of the experts who evaluated my system referred me to the Department of Energy guidelines which instruct a Manual J connected load calculation, but does anyone have anything that is in a New York plumber's manual or something where I can argue that the guy absolutely should've known better?



Many thanks in advance for your help with this unpleasant situation!

Danny Scully

Plumbing & Heating

In reality, plumbing and heating are two separate trades. Where they may often overlap, I doubt you will find anything in the plumbing code about proper methods for sizing steam boilers. Furthermore, what is the end game here?

nicholas bonham-carter

Steam installation standards NYC

The installation manual for the boiler, or the mfg's website should go into some detail about the importance of sizing the boiler to the connected load, or radiation.

What response has he made to your complaints?

Could the burner be down-fired?--nbc

NRW

The end game is to get him to fix it!

Thanks Nicholas - I'll check out the manual. He has responded to my complaints by going to look at the boiler, pronouncing it just fine, and refusing to do anything else about it. I've hired two separate heating specialists who say that the heating imbalance is because the boiler's too big, and both say (as did the proprietor of this site) that down-firing a gas boiler can be dangerous, producing carbon monoxide, and can also reduce the boiler's lifespan.

To the other poster, the end game is that I want the guy to make it right, and if he doesn't, I'm suing him. I've tried my best to talk to him about it and persuade him to fix it. He responded to my last request by hiring a lawyer. Two can play that game. I hired a master plumber who was highly recommended. He is also a general contractor. I supposed - wrongly and naively - that I could trust him to pick an appropriately-sized boiler. He didn't. In some cases, from what I gather, a bigger boiler, while not necessary, won't cause any problems. In my case, the third floor apartment is sometimes as much as 15 degrees cooler than the first floor apartment. I view his "mistake" as professional negligence, pure and simple. No experienced master plumber, especially one who claimed to have tons of experience installing new boilers, should make the mistake he made.

Dave in QCA

anything else?

When your contractor installed the new boiler, did he, by chance, also change any of the venting?

NRW

no changes to the venting

Dave - nope, no changes to the venting. In fact, both heating experts who evaluated the system afterward pointed to the fact that there were no vents on the horizontal steam mains and that all of the radiators throughout the building had the same vents.

In addition he did not install a check valve or a manual high limit pressure shut off control, both apparently required by NYC Building Code.

nicholas bonham-carter

over-sized boiler

main venting is definitely needed, and even if a new boiler of correct size is installed, the top floor may freeze. thermostat location/anticipation is also important.

i would suggest doing another survey of your radiation [needed for the court case], and confirm just how far off you are in the capacity of the new boiler.

was there any mention in your contract with the "master plumber" of following the manufacturers instructions, or of industry standards? the steam books available in the shop here will also be of benefit in helping you present your case, or in convincing him that he has installed an unworkable system.

if you are going to take a little time to replace this, then get those main vents in! you may also need to put larger capacity radiator vents on one radiator at the top of each riser, so as to let the air out. as i said before, a good low-pressure gauge will show you when your main venting is adequate. if you measure the diameters, and lengths of the mains in the basement, venerable guru steamhead can tell you what sizes, and types of vents should be installed as a start.

you are correct that down-firing the burner must be done by an experienced burner man with a combustion analyser, however it can be successful in some cases. did you tell us whether you have oil or gas?--nbc

NRW

here's how much bigger it is than it needs to be

It's a gas boiler. The two evaluations that I had done say the following:



1) The connected load calculation indicates that we need 358 square feet of steam per hour. The boiler produces 658. Thus, the boiler's about 1.75x than needed.

2) The heat loss calculation showed that I need between 90,000 and 120,000 BTUs. The boiler he installed has a 245,000 BTU input, meaning that the boiler is twice as big as I need.



Dan Holohan told me down-firing is a bad idea - carbon monoxide, reduces boiler life substantially - as did my experts. So I'm pretty much stuck, right? And yes, I do intend to have vents installed on the mains and the radiators.



Unfortunately, my 'contract' with the installer wasn't much of a contract - just a piece of paper saying what boiler he'd install and by when he had to complete. I don't think it included any standards of care (i can't find yet...eek.)



Thanks Nicholas for all your feedback. Much appreciated.

JohnNY

Proceeding at my own risk...

I'm a Master Plumber and one of the "experts" that came in late for a system evaluation here.

The boiler is an atmospheric Burnham IN8 with a bad, undersized header and bull-fed tees.

The poster needs an IN5.

The venting is minimal, but the system looks largely unaltered and I tend to take a conservative approach when considering any reconfiguration of an original design.

So, we'll wait until start-up and make some informed decisions on how best to get the steam to travel.



My client is in good hands, I assure you.