EDR Question +

Hollis

Ok, in one building we have a steam boiler and we need a new one. The place was a huge heat loser when we obtained it. No insulation in the walls, single pane windows, blower door showed very leaky etc. We fixed this the first year we got it.



Big GE downdraft boiler and all the radiators apparently kept the place warm before we got it, and continued to do so after. (after a lot of playing with balancing it really was pretty good on most days )



So now  in calculating for a new boiler and the radiators it feeds,...I would say that a smaller BTU output is called for but

#1  will the dynamics be all off?  Requiring a lot of fiddling with balancing again?

#2 Wouldn't the radiating be now be excessive with all the insulation added?

do it mean anything when trying to size the boiler?



Lastly,..any recommendations?..., currently its oil fired, but we would like to go with natural gas as we have the lines already there and said to be adequate and I understand a few boilers are engineered that they could be converted to either if one supply were hard to get or for some strange market dynamics be very expensive etc,

Is there a good one to look for?

Hollis

oops

Oops "does" it mean anything,......(no coffee yet) 

Steamhead

What

is your present EDR count? 

Hollis

well,...

Haven't actually measured it yet,...just wondering if what was there when the building was so un insulated,..would that be a problem now?,..would one put say a 1/4 inch plug in the vent valve area on some radiators or does it matter that you have ten radiators when 5 would heat the apartment. Since all units are in the same boat, would the amount of radiators have little to do w/efficient heating,..Ie if they were able to cycle on and only half of a radiator heats  up until the  main thermostat that controls the whole building being satisfied,...would there be say,.. condensation issues?  (babe in the woods here)  

crash2009

Hollis

The only accurate way to calculate what size of new boiler you need is by measuring the edr of all the radiators that will be connected to it.  All that other stuff, insulation, weatherstripping, etc. has little or nothing to do with it.  Start by making a list of all the radiators.  Then measure the side hight and width.  Then determine if they are column style or tube style, and how many tubes or columns they have.  Finally count how many sections they have.  Then multiply by the factor in the EDR chart.  Here is an example of my first one.  Its not 100% accurate, but it got me close, and at least, now I know how many I have.

JStar

Trim down.

You can run a heat loss on the space and tally up which radiators you need. Size your boiler to that new number. Just remember that once you have the size, you really shouldn't add or subtract radiators. You're better off keeping more than you think you might need. You can then balance the system with air vents. 

The Steam Whisperer (Formerly Boilerpro)

downsizing the boiler can be done

It is quite easy for two pipe systems by installing orifice plates in all the radiator supplies.  For one pipe, it is more of a challenge.  Look here for some more thoughts on one pipe http://www.heatinghelp.com/article/11/Hot-Tech-Tips/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell