Code Confusion… But Why?

The “new” 2010 AC Code is weeks old now, but the stream of questions on the AC Code continues. This is strange, because FRACCA has a course that has been presented more than eight times all over the State preventing AC Code Confusion. Locations include Tampa, Orlando (3 times), Miami (2 times), Ft. Myers, Sarasota, Ocala and soon Jacksonville. I have personally met with inspector groups to not only give “the Code”, but as Paul Harvey used to say, “the rest of the story.” The how and why items such as the thirty inch duct sealing rule came into being. I have taught the course solo and tag team with Ann Stanton from the State of Florida… Everyone that was interested should have been available to find a venue that was relatively close. It appears now that the Code is “the law of the land,” interest is rising concerning what is required. Did people think the AC Code Confusion would go away and they wouldn’t need to know what would be required? You may wish to contact FRACCA to see if a class is scheduled in your area in future 727-576-3225

Some quick answers to the most frequently asked questions include:

1. Yes, all thermostats, new construction and changeout are to be programmable type.
2. The thirty inches is measured from the duct to an obstruction (a truss web is not an obstruction) like a roof, knee wall, etc. This is a visual inspection with repair as needed (typically fiberglass fabric and mastic as mastic alone is not U/L 181 compliant). The contractor then certifies that this requirement has been met. No Class 1 BERS rater is required for CHANGEOUTS.
3. For new construction, if the Energy Code was “PASSED” using the Prescriptive Method a duct inspection is required by a Class 1 BERS rater. Leak test may be performed at “rough-in” stage or “final”. I would strongly recommend R/I inspection as the test at final would include the Air Handler and that item may leak morethan the maximum allowed for the entire system.
4. Manual J calculations are required on all residential installations, both new construction and changeout. They must be orientation specific, the direction the house faces and NOT a worst case scenario
5. Energy Calcs may be worst case, obviously, a new construction item.
6. Refrigerant locking caps are required on all “shrader” caps. Most inspectors I have spoken with are looking for the caps external of the machine. Check with your local inspector, as some may require caps on everything (internal and external).
   1. Equipment sizing is not to be done using AHRI data, but rather the manufacturer’s expanded data for the indoor and outdoor conditions used on the Manual J. There are requirements for sizing which include Heat Total and Heat Sensible (which actually define the SHR or Sensible Heat Ratio). Remember in Florida a LOWER SHR is typically preferred. This means greater dehumidification as a percentage of total cooling (If you attended the Code Class, I explained the “why” on this provision).
   2. Mismatched equipment is still not allowed. There are four methods to achieve a match. See my former articles, or read the Code to determine which works best for you.
   3. Plan review for a changeout may be required in your area at the discretion of the Building Official, but the Code does not mandate this. I have encouraged Building Officials and Inspectors that have contacted me to expedite changeout permits to minimize homeowner discomfort and encourage contractor compliance.
   4. Most municipalities are looking for all the necessary contractor supplied data such as Manual J, Contractor’s Duct Sealing Certification, Equipment Match data, Equipment sizing to be attached to the Air Hander for inspection.

Obviously, there is much more included in the 2010 Code, so much that the “One Hour CEU” course typically lasts longer than one hour. I have taught the course to at least 600 people, but there may still be a few contractors and inspectors that not had the benefit of attending one of the courses.

Looking out for you,

Bob Cochell

Guest column written by Bob Cochell, a FRACCA Board member and member of the Energy Technical Advisory Committee of the Florida Building Commission. If you have questions or have feedback to give on this article, contact your local chapter office, or contact the FRACCA executive office at mail@fracca.org or 727-576-3225.