Wikipedia explanation of the HERS rating (energy efficiency of a home).

Minnesota's Green Path and other "Green Building" programs use the HERS Rating of a home to determine it energy efficiency . Click the link below to see how the HERS rating works.

http://en.wikipedia.org/wiki/Home_energy_rating

Air sealing a new or remodeled home.

I found this article by Allison Bailes at "Energy Vanguard Blog". Good information if you are considering a remodeling project.

Whenever I see an older home being remodeled, especially if it's an extensive renovation, I always wonder if the homeowners and the contractor know what a great opportunity they have to make the house tighter. Whether they're opening up walls or adding new ones, working in the attic, the basement, or the crawl space, air-sealing should be part of the scope of work.

Here are a bunch of reasons why:

1. Keep conditioned air inside. Air leaks waste energy. If you're spending money on air conditioning or heating your home, why would you want to make it easy for that expensive air to escape?

2. Keep unconditioned air outside. Air leakage works both ways. When a cubic foot of conditioned air goes outside, it must be replaced with a cubic foot of unconditioned air coming inside. That adds to the heating or cooling load of your home and costs you money.

3. Keep bad air out, and stay healthy. Not only is the air leaking in costing you money, it's probably not the most healthful air either - moldy air from the crawl space, carbon monoxide and gasoline fumes from the garage, dead animal parts from the attic, pollen from outdoors... You get the idea.

4. Keep moisture out of your walls. When it's hot and muggy outside, you don't want to pull that moisture into your building cavities and start biology experiments. When it's cold outside, the warm, relatively humid air inside can condense inside wall cavities and rot them out.

5. Older homes with diagonal sheathing are very leaky. For the past 60 years or so, builders have used sheet goods (plywood & oriented strand board mainly) for wall sheathing and subfloors. Before that, homes had diagonal 1-by lumber (photo at right). There's a lot more air leakage through the gaps between all those boards than newer, plywood-sheathed homes have. Same goes for floors. Seal 'em up! Once you close up those walls, you've missed your chance.

6. Window and door openings are major air leakage sites in walls. Whether you replace windows and doors or not, you may well have access to the gaps between the window or door frame and the wall framing. Use an air barrier material (not fiberglass or cellulose!) to fill those gaps.

7. Those walls, floors, and ceilings may not have been open for decades, and when you're done, they'll be closed up for decades again. Don't miss this opportunity. If you're already in there doing remodeling work, take full advantage. You'll be rewarded with a house that's more comfortable, durable, healthful, and efficient if you do it properly.

There you have it. And if you're still worried about that old myth that you shouldn't make your house too tight, well, don't. A house does NOT need to breathe; people do.

Use of color can add punch to a project

Here is a link to a great blog about the use of color for your next project.

Dura Supreme Blog - For the write up!

Bob

Minnesota's Green Path-efficient durable homes for Minnesota!

Over the last 9 months of this year, the Builders Association of the Twin Cities (BATC) has been busy building a new "de-coupled green building program" called Minnesota Green Path. This program is much different than most green building programs that require an "all or nothing" approach.

The BATC is also working on a Green Path for Remodeling program to help consumers and remodeling contractors enter and choose a place along the green building path.

In both programs, the tested and certified Green Path homes will receive an easy to understand report tracking and memorializing the HERS index and green attributes that were designed into the project.

See this link:

http://www.mngreenpath.org/

for more information on this innovative approach to green building and remodeling.

Energy Savers: Energy Recovery Ventilation Systems

Here is an article about the use of a heat recover ventilator (HRV) in your home.

Recently, I was called to a remodeling customers home . She complained that the doors in the lower level of the house were sticking and not able to open and close properly. The weather here in Minnesota has been very hot with very high dew points. Some days the dew points were in the 80 degree range.

The day I was called to the house was a typical for this summer-a warm and humid day. Upon entering the house, I noticed that the house was cool and the air felt humid as well. I looked at the doors and asked several questions. Yes they have been running the air conditioning, no, they do not leave doors and windows open for fresh air. I looked at the humidistat and the reading was 66% at 74 degrees- Wow!

I went to the basement and saw that the HRV was set to run 20 minutes every hour.

The HRV was bringing in 90 degree air, cooling it slightly and dumping fresh air that was full of humidity into the cool house. The air conditioning would cycle off at it's set temperature without getting the humidity out of the air.

If you live in a state where you have high humidity in the summer, turn the HRV off. The article I have linked below states that you want to leave the HRV on to bring in humidity. This would be a good idea if you live in Arizona, but not for us here in Minnesota.

We brought in a commercial dehumidifier after turning the HRV to the off position. As the humidity level drops, the doors will begin to function as they shrink down in size.

Energy Savers: Energy Recovery Ventilation Systems