MerrickProperties

Bob Hastings, Northampton, MA, US
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MerrickProperties
Currently a student at UMass, Amherst in Building and Construction Technology while running a small remodeling business.

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restaurant bar-back

restaurant bar-back

This is the area behind the bar at a Northampton restaurant.  I used 3/4" oak plywood for its strength and dimensional stability.  I made all the cuts in my shop at home and assembled...

Laundry Room

Laundry Room

This is a basement laundry room that I renovated with porcelain tiles and removable wall panels for plumbing access.

Kitchen remodel on a budget

Kitchen remodel on a budget

My cousin gave me his old oak cabinets that were in mint condition.  Timing was perfect because I had just finished remodeling the bathroom and doing all the floors over in this apartment that...



Recent comments


Re: Why I Don't Use Cellulose or Blue-Jean Insulation

Here is where Riversong is mistaken:
"R-value is mathematically the inverse of heat flow. Double the R-value of an envelope and the heat loss through that envelope is cut in half. That's a perfectly linear relationship."

R-Value is mathematically the inverse of the U-value, which is just a factor of what goes into calculating Heat Loss. Because the U-value is also multiplied by surface area, temperature differential, and time to calculate heat loss, there is a curve to the R-value/heat loss relationship.

This debate has gone on too long. I only persist because the more we all learn and understand, the better of a chance we have in creating a more sustainable built environment.

Re: Why I Don't Use Cellulose or Blue-Jean Insulation

Riversong,
Try this wording and please (before you respond) check your facts with a credible source.

The savings seen from increasing from R-1 to R-2 is greater than the savings seen from increasing from R-30 to R-31.
The savings from changing from 0.7 ACH50 to 0.6 ACH50 is the same as the savings seen by changing from 0.5 ACH50 to 0.4 ACH50.

Here's some sources to reference:
www.masssave.com/~/media/.../Icynene-presentation.ashx
http://www.buildings.com/tabid/3334/ArticleID/6061/Default.aspx


Sincerely,
Bob Hastings
B.S. Building and Construction Technology, UMass Amherst
MA CSL #105337
BPI Building Analyst and Envelope Certified Professional
EPS Certified Home Energy Auditor

Re: Kitchen / Dining Room Remodel

beautiful work.

Re: Why I Don't Use Cellulose or Blue-Jean Insulation

Riversong, I agree with the first paragraph, when planning new construction, the holistic approach is key. However, the bigger fish to fry here is in renovations these days. (about 550,000 new homes built in the U.S. in 2009, compared to over 2,000,000 in 2005).
What you are wrong about is the "diminishing returns" and linear relationship. It is you that has it backwards. The heat loss/R-value relationship is not linear, there is a strong curve with drastically decreasing slope after R-20.
The convective heat loss/air change rate relationship IS linear. Air sealing beyond 0.3 ACH requires mechanical ventilation to ensure health safety, yes. But well worth the energy savings and added home comfort. HRVs are affordable when considering all the benefits.

Re: Why I Don't Use Cellulose or Blue-Jean Insulation

I'd like to point out that "green" building is about conserving energy, not just in the construction, but more importantly, in the use of a building. There are two major factors of energy use... 1. R-Values (wall thickness, insulating materials, and frequency of thermal bridges) and 2. Convection!! I know this isn't the point of this article at all, but the debate went way too far without mention of air sealing (which you get with spray-foam products).
The energy savings from R-1 to R-20 is incredibly significant. However, the savings level off as you increase insulation beyond standard amounts.
Energy savings from air sealing does not have a leveling-point. The more you seal, the more you save, so long as you either provide mechanical ventilation to remove humidity and CO2 from the home, or don't seal the home to below 0.3 ACH (air changes per hour).
I'm a big fan of cellulose fiber, but in conjunction with sealing (either with 1G foam or simply caulking).