doubling attic insulation - does it help?

[TURTLE]

This is Turtle.

10 feet of insulation was a example of there is a limit to having too much and just as not having enought.

TURTLE

[PaPaPeng]

Attended a house building course years ago when I was building mine with sweat equity. On insulation calculations the data was that up to R30 the gain in insulation efficiency is a straight slope upwards. After R30 the slope flattens which is to say any gain in insulation efficiency ( reduction in heat loss) after R30 is very marginal. That is you won't get your money's worth beyond R30.

[PipeDown]

No doubt ~$1400/yr savings is very impressive. But how much did all new appliances, new water heater, new windows, lots of insulation and whatever else cost you. How many years will it take to pay back. Sounds like you did a lot of remodeling at the same time and energy upgrades were just addons (above and beyond the cost for basic installations). I assume you didn't do all the work just to save fuel, there must be some cosmetic payoff. The best time to upgrade is during a remodel.

[Anonymous]

One thing I note is that projected savings are figured at todays fuel/energy cost. I have not kept track but I suspect that my actual fuel savings from buying a 5 speed manual Honda civic 5 years ago rather than a suk is a bit more than was projected. And if you think energy prices are going down (except in world wide depression) I have a great mony making deal for you. Stan