three. You wrote, "You all over again are incorrect a R30 vented attic will not likely outperform a unvented R20 employing foam." I do not know what paragraph, if any, that you are quoting from. I by no means reported any this sort of matter.
If you're referring to the article in Electrical power Style and design Update, then The solution is Indeed, I'm the writer.
Not one person is arguing in favor of a "typical fiberglass-insulated dwelling." In case you study what I've written, I advocate that every single property be examined which has a blower door.
Eventually, I concur with Rich Brown - if your home satisfies (or ideally far exceeds) the code in the performance route, then why be concerned about a certain amount of insulation that is predicated on the prescriptive approach?
three. You have said that my posting is filled with misinformation. If so, I invite you to definitely cite an illustration of misinformation.
Martin , it truly doesn't matter Everything you create, now will it. You requested Scott to supply one merchandise where by your article was incorrect, properly I gave you one particular where you claimed R-38 was required in NC weather zone three, that was incorrect, ideal? Martin, I know it's challenging but cannot you say, I made a blunder this one merchandise?
4. Regarding your level: "We've got audited many properties working with R30 and R38 cellulose the place the homeowner complained of consolation issues in their higher ranges" — I have no explanation to doubt you. There are several explanation why this is possible; I believe the households you audited had inadequate ceiling air obstacles and insulation installation defects.
So, company website Should you have an incredibly tight house realized by means of aggressive air sealing, and also you are decreasing the thermal bridging by, lets say, R-10 insulated sheathing on the outside... growing the thickness of insulation during the wall/ roof cavities is just not all that vital?
Why do you not publish the complete letter from Victor as I'm fairly positive he wouldn't symbolize R-20 as Assembly prescriptive R-price. As you've got misread most of my info it ought to be obvious you also can be misrepresenting Victor's letter.
Martin, I think it is rather crystal clear that foam by it self is more expensive than fiber glass or cellulose. Unquestionably each individual homeowner is or must be worried about the associated fee great things about including additional amounts of insulation and if the rise in the degrees will supply a justified ROI in the course of the life of the house. Doubling the level of R mounted doesn't at the conclusion of the working day provide for any two times the Electrical power financial savings. Having said that adequately installing foam insulation at a lot less than prescriptive code specifications will almost always offer a homeowner with reduce Electricity cost than if that they had built the house applying regular procedures.
I found this report on "The Economic Thickness of Thermal Insulation." I was not in a position to figure out who executed the study, but Most likely you could potentially share your thoughts...
Certainly, the warmth movement as a result of R38 is forty seven% lower than by R20. When you implement R38 for the roof deck, You aren't minimizing the warmth move through the ceiling by 47%. The attic functions as a buffer zone. The dilemma is forty seven% of what, and at what Charge. David Butler
Here's just how I'd phrase it: Assuming that two roofs have equivalent thermal bridging, the warmth decline through a roof which is insulated with R-forty Icynene will probably be half the heat loss via a roof insulated with R-20 Icynene.
All of this theoretical things is nice and "they should change the codes" is a fantastic assertion that leads nowhere. In the long run, I continue to really have to complete and pass a ResCheck. And this is a ResCheck that does NOT just take air-sealing into account, and in North Carolina is just not permitted to Use a UA tradeoff for super-efficient HVAC equipment.