16 years later...

[dablack]

Originally Posted by AC_Hacker

However, I'm now pained to see this thread devolve into a pontification of opinion regarding the undesirability of 'too much insulation'.

I really wish that this gumption-diluting turn of the thread had not happened, and I am puzzled and concerned why it has.

SH... I myself, have been a mechanical engineer for 43 years, during which time my career also included a 20 year stint as a college instructor of engineering: mathematics, thermodynamics, physics, manufacturing processes, etc.

It pains me to see your use of the phrase, "As an engineer...", and then to see the dubious advice that follows those words...

I know that it is regular, expected practice for engineers to substantiate their claims with clear mathematical proof. It would be a proper thing for you, if you are going to claim to be an engineer, to substantiate your assertions 'as an engineer' with clear mathematical proof, and not your local folklore.

(* I think that EcoRenovators need to be aware that oil-rich Oklahoma, the state where you live, has the lowest energy costs of any state in the USA, and also discourages solar energy and wind energy, and may be the reason that your folk-loric energy advice is so tepid. *)

I say all this because years ago, I made the mistake of accepting 'common wisdom' (folklore) and insulated my house with a 'reasonable amount' of insulation... I seem to recall that the same phrase "insulating with dollars" was used then, too. In the following decades, I did waste a very large amount of money through heat loss, because of the very large rise in fuel costs (which, in the long term will continue to rise). Now I am ripping out the 'reasonable amount' of insulation and putting in the most effective insulation I can possibly afford. My energy bills are beginning to speak to the success I am having.

SH, I would like you to please put me in touch with 'your client' who didn't listen to your advice. I would like to speak by phone or email to him (or her) myself to see just how much he regrets having wasted so much money on insulation. I'd like to see how much he regrets not joining his fellow Americans in shouldering the burden of foolish energy use.

It would be nice if you had an international perspective, if you were as progressive as Scandinavia in their energy conservation in their housing designs. It would be useful if you were as thorough as the Germans and actually understood at least the principles of Passive House design and planning, and realized the interplay between all the elements of heat conservation design.

It would be nice if you applied your engineering talent (if it exists) to initiating projects that typical EcoRenovators might benefit from, complete with photos and diagrams and actionable details. Your SIP barn is a start. I'm sure that it will be useful to others who also want to build a barn.

SH, will you please get back on track and show us the numerical details of how your efforts to conserve have reduced your energy use? If that has actually happened.

That is the purpose of this thread...

-AC

WOW! Um ok. Not sure why things got insulting. I have a question AC? At what point does the total amount of insulation become silly?

I think SH's point was to use payback period to help decide how much insulation to use. These days we have access to REAL data to help us decide how much to use. No folklore involved. While building my house, it was easy for me to get a bid for spray foam. I knew how much exterior wall space I had and how much it was going to cost to use spray foam (high and low density) or fiberglass. Then using that information, I could decide how big of an AC system I wanted to buy. As an engineer (can I say that without posting my transcript?), with a little reading, those things can be figured out. Actually, you don't need a master's in mechanical to do the math. Lots of good data out there. I could have filled the stud bay with high density foam, but putting in 4" of low density was "good enough" for where I live and the design of my house. I might have filled the bay with the low density stuff but I found some used chicken house blue rigid foam to use on the outside. This is all just a math equation.

If you double your insulation, does it cut your heating cooling bill in half?
Where do you draw the line? It is up to the individual on how much they want to invest to get that last little bit of return.

I get into the same argument when someone I know buys new Honda "because it gets 35 MPG". They owned a perfectly good car or truck that got 20 - 25 mpg but they think the 35 mpg car (with full coverage insurance) will save them money. HA! Someone didn't do their math!

Now, I'm going to go look at my energy bills so I can post up actual numbers for my before and after.

Austin