Insulation on Supply Ducts R8 Required However Tradeoffs = R6 BUT

[Mule]

Interesting thing here. The IRC requires R8 insulation on ducts however you are allowed to reduce that if you bump up the SEER rating on the AC...........However the enrgy code requires R8 with no trade offs.

Just thought I would throw out my findings.

 

[JBI]

When in a Res Code building, Res Code applies - unless you're talking about deviating from the prescriptive path, then you use the Energy Code. Personally, I find the commercial Energy Code to be rather lax compared to the Residential Code requirements for energy conservation. That there are no tradeoffs is the strongest measure I've seen in the ECC.

Of course, the reduction 'assumes' all components are properly installed and maintained... A higher SEER rating ain't worth a tinkers' damn if the install and maintenance are no good. JMHO.

 

[88twin]

hey mule... could you please point out where that reduction is?

im looking at 2009 IRC

thanks

 

[Mule]

It's a trade off in Rescheck. If you are 10% above compliance you can substitute R6 for R8.

There is also a trade off for using a higher SEER rated unit, 14 or more or if using a 90+ efficiency unit.

These trade offs are built into the software.