How illegal is this? Vented gas fixtures

[Jadnashua]

A rough estimate for required room volume on atmospheric fired/vented gas or oil appliances is 50cuft/1K BTU of burner. In this case, you'd have to add up all of the max fire burners to see how well that works out. That 'rule of thumb' assumes an older, leaky house, which may or may not be the case. TO work properly, you may need to engineer makeup air into that space. Usually, each appliance will have a discussion in their installation manual, and if the inspector is sharp, he should reference that to determine proper adherence, since the rule of thumb is overridden by the manufacturer's installation instructions in most cases, especially if it is more than the 'minimum'.

This is one reason why closed combustion appliances can work so much better...first, they don't suck already conditioned air through all of the cracks in the building you have to condition again, and the burner gets the proper air for reliable/consistent fuel/air ratio and maximum efficiency.

In the worst case scenario, if all of the appliances are firing at once, and consider people may have their stove hood vent running, the dryer on, and maybe a bathroom vent or two, and you could easily get into a situation where those things are back-venting into the basement, and CO and other combustion byproducts are lighter than air...they will get into the living spaces.

At the minimum, I'd want to see at least a couple of CO detectors in the building...one near the appliances, and at least one more in the living area. Cheap insurance. I know I bought one for my sister, and a few months later, it saved their lives when their furnace heat exchanger started to leak.

A good reference with some examples and background info is here: http://www.ashireporter.org/HomeInspection/Articles/The-Word-Combustion-Air/2233

 

[Tom Sawyer]

The best course of action would be to call in the mechanical inspector but, I seriously doubt that all four of those appliances can be vented into a pipe that size although I don't know he BTU output of the appliances. Clearance to combustibles with singe wall vent is 6" to 36" depending on the equipment but in this case it is 9" which it appears not to be throughout its entire length. The wirs on the backside are definitely too close. The hangers are not properly spaced. The pitch is inconsistent and improper. Only some of the joints are sealed and those are sealed improperly and that's about all I can see from the pictures but if this is rental property, I strongly suggest upping the personal injury to about 50 million.

 

[Sponsor]

 

[Lordoftheflies]

By closed combustion you mean they have their own air intake line direct to the outside for combustion air, correct?

Thank you for the CO suggestion. I spoke to the homeowner and he said he already had CO detectors upstairs but not downstairs so he's going to put two downstairs as well as get someone trustworthy to come over.

Oh and to answer an earlier question I was there to demo the existing electrical outlets, lines, etc. that were damaged and to run a few homeruns as well as to meet the PSEG guy to have him install a new meter.

Thanks for all the repsonses. I sent the HO an link to this thread. Hopefully it helps! Thanks again.

 

[Dana]

Yes, "closed combustion" or "direct vent" are terms for forced-draft combustion appliances that duct the combustion air in directly rather than drawing it from conditioned space.

The BTU ratings on those tiny boilers are probably about the same as the water heaters, but could be 2x that of the water heaters, hard to say. The smallest of the Williamson Thermaflo series is a 52,000 BTU unit, but the 70,000 BTU unit uses the same 4" stack that we see in the photos. The water heaters could be only 40,000 BTU or they could be 55,000 BTU, but assuming you have 110K of water heater and 140K of boiler that's still only 250,000 BTU of burner.

It looks like it has about 20-30 "equivalent feet" of lateral vent run to where it turns skyward. If it's a least 25-30' from the basement ceiling to the top of the stack it means it's probably still kosher from a sizing point of view if it's 7" or 8" B-vent, but not so much if it's only 6", but only assuming the slope and clearance issues etc can be brought up to snuff. If the boilers are the 52K versions and it's probably OK even with 6" B-vent. Consult the chart on p12 of this document.