Page 23 - Green Builder November Issue Codes Update

2018 IECC Public Comment Hearing

Mechanical Equipment Tradeoff

HIS DEBATE HAS BECOME a triennial tradition.CREDIT CHRISTIAN DELBERT“disingenuous” for proponents of the ERI path to also oppose an
equipment tradeoff. Another person noted that window tradeoffs
T This particular tradeoff was first removed from the are already allowed, some states have chosen to amend their energy
2009 IECC, but this argument has returned for every codes to allow equipment tradeoffs, and many above-code programs
code cycle since. Each time, governmental members also allow an equipment tradeoff.
voted to keep it out of the model code. At this year’s
code development hearing, the committee approved Both sides of this debate would probably agree that changing the
the proposal. But there was an assembly motion to NAECA standard would go a long way towards ending this seemingly
disapprove, an action agreed to by 57 percent of participants in never-ending argument. But to get the NAECA standard changed
an online vote.
takes an act of Congress! (Seriously; it needs their approval.) The
In RE-134, NAHB is taking a slightly Department of Energy could have spearheaded the update long ago,
different approach than in its past three but faced resistance from the gas industry. It appears as though
attempts to reinstate this tradeoff: a UA something may finally change on this front, but not for at least four
backstop. Using a 115 percent multiplier, or five years. GB
this would not allow a thermal envelope
less than (approximately) a home built to
the 2009 IECC. (In some climate zones, it
would be more stringent than the 2009
IECC, while in others it would be less
stringent.) There are also seven public
comments attached to this proposal,
though most are seeking disapproval.

According to one executive we spoke
with, the problem resides with the
NAECA standard. Because 80 AFUE is the
lowest allowable (new) furnace rating,
and nearly all furnaces installed in cold
climates are 90 AFUE (or higher), a lot
of credit would be given for something
that’s already viewed as necessary or
commonplace in the market. Therefore,
if an inordinate amount of credit is given,
insulation levels could be lessened. That
would lead to less-efficient thermal
envelopes, which would in turn make
the efficient equipment run more often than would otherwise be
needed.

Other proponents of RE-134 point out that such a tradeoff is
allowed in the commercial energy code, as well as the ERI path of
the residential energy code. One executive we spoke with called it

The topics above, plus many other proposals, will get sorted out online
throughout November. It is our hope that the governmental voting member reps

take in as much information as possible before casting their votes.

Mike Collignon is the executive director and co-founder of the Green Builder Coalition.

www.greenbuildermedia.com November/December 2016 GREEN BUILDER 21