NTL1991
New Member
There's a bit of a backstory here... Years ago my 3-family home (1948) had 1-pipe steam with a WM SGO-3 oil boiler and a 75 gallon NG water heater. Everything was separated for individual metering; plumbed the three apartments in PEX with baseboard heating loops, installed boilers and individual 40 gallon NG water heaters, re-piped all the hot fixtures in the house, and everything seemed right in the world.
We started off by replacing the single oil tank with two half-size's, converted the SGO-3 to a WGO-3 for the 1st floor, Installed the LAARS Newport NP-85 oil fired for the 2nd, and a small Superior NG boiler for the 3rd.
We have since replaced the WM oil and Superior NG with matching WM CGA-25 NG boilers, which are much better sized for the small 1000 sq ft apartments. The LAARS oil is still there for the 2nd floor. It will eventually be replaced with a NG boiler too when it's time comes.
The conversion is coming back to bite us, though, in the form of draft issues with the chimney. More fuel-burning appliances, more openings in the chimney, and the house is getting tighter with weatherization. I had an energy audit done with RISE, and all my insulation work is dependent on fixing some low draft issues.
They reported the following draft issues:
The first thing they recommended I do was add a combustion air inlet. I did, in the form of 2 - 7" round galvanized vents and insulated flexible duct to a foot above the floor near the appliances.
I think if I can replace those three water heaters with either indirects or sealed combustion units, I should have sufficient draft for the three remaining boilers. I'm not sure of sizing limitations with those small WM CGA-25 boilers, so I've posted another topic about Small Boilers and Indirect heaters.
Any advice?
We started off by replacing the single oil tank with two half-size's, converted the SGO-3 to a WGO-3 for the 1st floor, Installed the LAARS Newport NP-85 oil fired for the 2nd, and a small Superior NG boiler for the 3rd.
We have since replaced the WM oil and Superior NG with matching WM CGA-25 NG boilers, which are much better sized for the small 1000 sq ft apartments. The LAARS oil is still there for the 2nd floor. It will eventually be replaced with a NG boiler too when it's time comes.
The conversion is coming back to bite us, though, in the form of draft issues with the chimney. More fuel-burning appliances, more openings in the chimney, and the house is getting tighter with weatherization. I had an energy audit done with RISE, and all my insulation work is dependent on fixing some low draft issues.
They reported the following draft issues:
The first thing they recommended I do was add a combustion air inlet. I did, in the form of 2 - 7" round galvanized vents and insulated flexible duct to a foot above the floor near the appliances.
I think if I can replace those three water heaters with either indirects or sealed combustion units, I should have sufficient draft for the three remaining boilers. I'm not sure of sizing limitations with those small WM CGA-25 boilers, so I've posted another topic about Small Boilers and Indirect heaters.
Any advice?