Estimating Efficiency Of Different Wall Systems

monticellohomes

I was in a HBA Green Building meeting the other day and one question we came up with that nobody really could answer was:

"When building green how do we establish a way to know/estimate what green items will be necessary to fit both what the customer wants and fits within their budget?"

We were discussing this years St. Jude home in our area and how it scored on the blower door test and trying to establish how certain items or practices produced that score. Pretty much trying to establish the Return on Investment so when speaking with a homeowner about building a green home we can tailor it to their budget, it might not be as green as the next one but it was what they could afford. Or pretty much figuring out how to score an HERS rating of 85 vs. 60.

The other item we were discussing was the difference in efficiency between the ZIP system, SIS panels, OSB with house wrap, etc.

Bob Kovacs

You've got to do energy models for each of the proposed systems, and then determine what the $$ savings on the utility bills would be for each. You can then look at the cost of the system itself and compute the ROI.

SawGearGuy

Thanks for this.

__________________
Brandon Vaughn
SawGear
www.sawgear.com

solartech

Energy modeling software is readily available and quite often, it is free to download. I have used HOT2000 for nearly 25 years and it has proven very accurate for northern climates. It is available from the Natural Resources of Canada website. The DOE has eQUEST and HEED. These are all good programs, but you can only get good results, with good input. The user must have good knowledge of heat transfer and materials.
I like to run analysis on different wall systems for the same building and identify the variables in yearly energy use and equipment size requirements. This helps the builder and homeowner choose what is right for their location, design and budget. The 2009 IECC energy standards should be the starting point for all buildings.

15element

very useful