I went a couple years with the mindset about “we are not Code inspectors”,
When I did home inspections, I carried my code books everywhere I went, it is what builders understand. Building code is subject to interpretation, as well as if they are adopted or modified for a particular area.
However, when we put on our home inspector hats, we have got to comply with our rules and regulations. So when does building code fall under home inspection regulations? It is when a significant issue (as specified in the home inspection rules) does not function or operate as intended, plus anything else we want to throw in there, if we’re qualified to do so.
When something is done against the wishes of the AHJ concerning new construction, that is the job of the code inspector. It has yet to fail or cause a significant issue because it is brand-new. Inspectors are not required to predict future failures, or determine why the failure occurred.
R403.4Mechanical system piping insulation (Mandatory).
Mechanical system piping capable of carrying fluids above 105°F (41°C) or below 55°F (13°C) shall be insulated to a minimum of R-3.
R403.4.1Protection of piping insulation.
Interpretation of the code: Section R 403 is a section of the “Energy Conservation” code. The range above 10 5°F and below 55°F is reference to when heat transfer is accelerated. For every degree Fahrenheit above or below these temperatures increases the multiplier in the heat transfer equation. 10°F above or below design temperature is a heat transfer multiplier of 10X.
The 24 inches between the house foundation and the condensing unit may fall under your code inspector’s interpretation, but it is not a concern for the energy conservation reasons this became a code.
Piping: can be interpreted to include air ducts, which it appears to be the perspective of R 403. It must be insulated, and the insulation must not be subject to damage. A fluid can be a liquid or a gas (air).
Go to M1411.6
M stands for mechanical.
M1411.6 Insulation of refrigerant piping.
Piping and fittings for refrigerant vapor (suction) lines shall be insulated with insulation having a thermal resistivity of not less than R-3 and having external surface permeance not exceeding 0.05 perm [2.87 ng/(s · m2 · Pa)] when tested in accordance with ASTM E96.
They want a minimum of R-3, why?
Because insulation will go below dew point and cause condensation, which is what they’re trying to avoid.
Also, the external surface permeance requirement is to prevent air/containing water vapor from entering through the insulation barrier.
If you see that the 24 inches between the house and the condensing unit is causing an issue, then you are required under home inspection rules to address it.
Your mechanical and conservation codes are just like the ones here, and most places where I work in the field. You guys can interpret this the way you want, and deal with it as it goes down the path. I seem to get more stuff done when I recommend a preventative maintenance issue rather than a home inspection issue. I never go up against the AHJ, but do have conversation with them for clarification. We don’t like people calling us out, I’m sure they don’t like it either.
The insulation prevents condensation on interior surfaces, but why would you need to control condensation outside?
This thread is about water production against the building and energy efficiency questions. 24 inches of armor flex is not going to do anything significant. If there are large sections in the attic, this will be/is a moisture issue specifically being addressed by the building code.
Thanks for the links Dave.
) Code. That’s when I started getting into the Codes. Bottom line the Code is the reference material, if something is not installed correctly I like to provide references. BTW the Code (in FL) also requires that systems and equipment be installed per the Code and per the manufacturer’s installation instructions; and in the event that one is stricter than the other the stricter applies.