steam boiler question

joelm

I have 2 different quotes, for 2 different models for a steam boiler installation from 2 different professional contractors, wondering who you think is correct?...

My total radiator capacity is 143.50 square feet, i verified this by steam radiator charts from the net, system is for first floor, longest supply run to furthest radiator is no more than 18'

Contractor a- suggest a burnham in3 with a output of 158' square

Contractor b- suggest a burnham in4 with a output of 271' square, after questioning that suggestion, he said they did not calculate for supply piping and large rooms.

am i missing something?, what would a larger steam boiler do so close to radiators?  please offer your opinion, thank you.

Dave in QCA

Boiler Ratings Clarified

The I=B=R boiler rating in sq ft already has an allowance of 34% for piping losses and pickup.   That should take care of your piping losses assuming that they are insulated, maybe even if not since your main is relatively short.

Also, Contractor B's comment that he was allowing for large rooms indicates that he does not know how to size a boiler.  The boiler is to be sized to the connected radiation.  You can't put any more heat into your home than the radiation can emit.  Do you know what the old boiler is rated at? Perhaps contractor B just matched the new one to the old?

If you want some folks on here to check your EDR numbers for your radiators, post a picture of 2 or 3 of them and also indicate the measurements.  I'll look em up just to verify you are right.

So far, from what you say, Contractor A is the only good choice you have.

Rod

Measuring the EDR

Hi-  I'm curious-  Did both the contractors measure physically measure the radiators on their own or did they just use your calculations?

- Rod

joelm

re steam boiler

Both contractors measured the radiators, and got 143.50 and 142 square feet, i measured and calculated thru the respective chart i found on the net,  36" tall 3 tube @ 3.50 square feet per section, with a total of 143.50 square feet all together.

all supplies are insulated from the boiler to underneath the first floor radiators, i just tend to think the in4 is way too large for the application

joelm

re: steam boiler

the present boiler is oil, not sure of the gph rate or btu output, old piece of junk, trying for the national grid discounted oil to gas conversion boiler price

Rod

Steam Boiler Replacement

Hi- Well if three people have calculated the EDR of your radiators and come up with approximately the same figure I guess you can consider the EDR figure is correct. It sounds as though the IN3 is the size you need.

    Here's is the link to the Installation manual for the IN3 

http://www.usboiler.net/products/boilers/independence/assets/manual-ind.pdf

i would carefully read it over and pay particular care to read and understand the piping configuration, pipes sizes and specified height dimensions  of the near boiler steam piping (Page 16 & 17 in the manual)  I would also go with the "second boiler supply option"-(see Page 17 -Minimum Pipe size table) as having the second supply riser will slow down the velocity of the steam which will result in better quality (Dry) steam.

     It is very important that the installers follow the manual as these are "minimums" for a properly working boiler installation. This would seem to be self evident but you'd be surprised how many pictures of supposedly "qualified" installer's work we see posted on the wall by upset homeowners, which shows that the installers obviously didn't even open the Installation manual, let alone read it!  This is why it really pays for the homeowner to read and understand the Installation manual themselves.

- Rod