Efm 520 asme rating

Pacowy · Post by **Pacowy** » Fri. Nov. 15, 2019 8:47 am

In addition to preventing the boiler from drawing cold air into heated spaces to satisfy its combustion air needs, the controlled provision of makeup air from outside also prevents things like clothes dryers, range hoods and bathroom vents from working against the chimney draft to pull combustion gases (including CO) into the house. It may appear counterintuitive, but it makes a fair amount of sense, and AFAIK has been incorporated in the International Building Code. As long as owners of drafty older homes have opportunities and incentives to invest in measures to tighten up their buildings, it seems like fair game to include them. And I heat one of the draftiest old homes around, so I don't like even thinking that, let alone saying it.

Mike

CapeCoaler · Post by **CapeCoaler** » Fri. Nov. 15, 2019 9:22 am

It is actually a provision that makes sense...
Older homes were not tightly sealed...
Plenty of makeup air...
As energy programs regulate new construction methods...
And retrofit programs tighten up the older homes...
Provisions have to be made and enforced for residential combustion air...
Just like water will always find a way into a boat through any possible hole...
So will air into a house...
Just gotta control the entry point...
Non-residental structures have had to do this by code...

Canaan coal man · Post by **Canaan coal man** » Fri. Nov. 15, 2019 9:48 am

Well I think I just made my mind up it will be a vented plywood insert to fit a basement window.
Now what’s nice is from what I have read most these 520s run on feed of 4
So In reality I should have enough combustion air with out a window vent.

coalkirk · Post by **coalkirk** » Fri. Nov. 15, 2019 11:15 am

Mike is spot on with all of his points. You should definitely do the combustion air make up pipe. It probably doesn't need to be as large as the calculations indicated.

McGiever · Post by **McGiever** » Fri. Nov. 15, 2019 1:26 pm

Bottom line, burning coal needs and will get the air it needs...you may chose where it gets that air from or leave the burning coal to find that air wherever it can find it from throughout the cracks and gaps throughout the less than perfect building structure. You're paying the same no matter where that air comes from, but one way it effects the occupant's comfort more so...