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Green building assessments versus energy audits

How whole-building performance evaluation avoids unintended consequences

Some common building assessment tools (clockwise from top left): infrared digital thermometer, pin-type moisture meter, digital manometer (pressure gauge), digital hygrometer, and electronic radon meter. A decent model of each tool can be purchased for less than $200, often less than $100.
Image Credit: Peter Yost

Energy audits can be a single slice evaluation of home performance, just looking at energy, albeit in a comprehensive analysis of energy performance. Whole-house assessments are green because they take a systems integration approach to evaluating home performance, looking at the individual and combined effects of energy, water, indoor air quality, and durability performance.

What can be troubling are the unintended consequences of straight energy improvements, erosion of home performance that can inherently and inadvertently accompany reducing heat loss/gain and air sealing. Here are the most common unintended consequences of energy improvements:

• Combustion safety– Every combustion appliance, be it a gas water heater, propane cooktop, gas clothes dryer, or oil-fired boiler needs make-up air. Any one of these appliances may have exhibited adequate performance when the home was leaky, but air tightening can result in backdrafting problems and increased carbon monoxide (CO) levels inside the home.

Pressure measurements using a manometer and CAZ (combustion appliance zone) worst case depressurization testing address this issue.

• Radon– Air tightening can increase radon levels in a home. When I insulated and air sealed our basement about 8 years ago, the radon levels doubled, from about 6 picocuries per liter (pc/l) to over 12 pc/l. Since radon is an odorless, colorless, tasteless gas, as well as a known carcinogen, keeping track of radon levels should start at the assessment and carry through as home improvements are made.

Short-term electronic testing (2 – 3 days) for radon can give an adequate indication of radon problems (in a closed-up home) as part of the initial building assessment.

• Moisture– Energy flows through building assemblies dries them out. A level of wetting that was never a problem can easily become one as we increase the energy efficiency (decrease the energy flows through) of a home. We have to worry about 4 ways moisture moves about: bulk water (ground water, rain, snow), capillary water (wicking through porous building materials), air-transported moisture (moisture condensing as air leaks into a home during the cooling season or out of a home during the heating season), and vapor diffusion. Any one of these or a combination can create a mold or even rot problem for a home whose moisture performance has not really changed while its energy performance has.

Gross level inspection of bulk water drainage (over the structure and then ground drainage patterns), moisture meter testing, blower door testing, and vapor profiling (relative vapor permeabilities of building assembly components) can all be done as part of the building assessment (we will be addressing the vapor profile concept in a subsequent blog).

• Structural– It’s not uncommon for previous electrical, plumbing, or HVAC work to have compromised the home’s structure. And this is something that can be a problem with new work as well. On the other hand, solving existing structural problems or plans to avoid new ones can be an important part of or follow-up to the initial building assessment.

Visual inspection of the home’s framing can largely be done without invasive inspection.

• Electro-magnetic fields (EMF)– Although the science and human health impacts of EMF in homes are far from adequately researched or understood, low- or no-cost prudent avoidance is a good policy. Common problems include the way the electric panel is grounded to plumbing, knob-and-tube wiring, and devices such as microwaves.

A gauss meter is easily used to assess likely EMF problem locations.

Each and all of these issues can be readily assessed and then addressed in a whole building assessment and subsequent home improvement plan. We will take a closer look at each of these issues in subsequent blogs.

5 Comments

  1. Craig Olsen||#1

    Green Building
    Glad I just got certified by Building Performance Insitute as a building and envelope analyist. I also use Flir IR for mold and temperature differences, radon test kits, CO tester, and a Gauss meter. Can't wait to get folks healthy and safe in Southwest New Mexico.

  2. Paul W||#2

    EMF
    I have seen the EMF issue raised now in comments to several issues. If this is a real concern, maybe an article on EMF, what it is, and how to reduce, eliminate, or minimize exposures both through design/build and lifestyle changes might be appropriate.

  3. Eric Chou||#3

    EMF
    I, too would like to hear more about EMF. I got rid of all the fluorescent lightbulbs in my house, in spite of the energy implications, because of what they do to the electrical current, causing high frequency voltage transients (dirty electricity), and the health dangers of mercury gas if one is broken. These CFC bulbs are not green, in my opinion. I replaced them with neodymium "natural light" incandescent bulbs. We also avoid microwaves, induction cooktops, wireless routers, cordless phones, smart meters and smart appliances for health reasons. The health of my family trumps the energy efficiency of my house. Also, you can expect a lot of disinformation on the research currently available, because of corporate financial incentives. These lectures are a good introduction to the topic:
    http://electromagnetichealth.org/watch-videos/

  4. Paul W||#4

    Not convinced
    I am not entirely persuaded by all of this after review of several sites. While there may be some merit to the underlying principals, it appears that there is a fair amount of fear-mongering, intellectual dishonesty, and downright quackery as well. Reading some of this would lead one to believe they needed to start building faraday cages to sleep in!

  5. GBA Editor
    Martin Holladay||#5

    Response to Paul W
    Paul,
    I agree with you. Evidence of harm is lacking.

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