Hello! I'm a carpenter starting my own business and I'm trying to find some solid numbers and research on maintenance and emergency maintenance costs for a presentation. I know the price of things only vaguely from a first hand basis. I've worked almost entirely cost plus and I've never really had to bid for anything, and haven't needed to research. I know things like "It'll cost about X." Which doesn't help when I'm trying to present empirical data even though what I say may be true.

Where can I find studies that go into detail about water heater life length? Or the effects of partial suction line blockage on the life of an AC compressor? Or how much extra wear a furnace has when it is short-firing? Or studies on dew point control using vapor barriers? I know these studies exist, or Tyvek wouldn't.

All the academic journals I've found so far have focused pretty much on structural engineering, "green" composite material longevity and efficiency, and civil studies. Does anyone know a good resource for this kind of information?

Also, if there is a reputable source that has an empirical consensus based "average cost" for repairs and maintenance I would be forever grateful.