LOW-E insulating glass U value than ordinary hollow glass much lower
Ordinary insulating glass 2.6 or more, LOW-E insulating glass 1.9 or less.
6 +12 +6 ordinary 2.8 or so, offline low-e around 1.8
Under normal circumstances 6 +12 +6 ordinary hollow U value of 2.8 or so, loe-w in about 1.8.
