EMF management

What I love about sharing our deep energy retrofit experience is the suggestions and feedback we receive on occasions from our readers.

Jason la Fleur (Alliance for Environmental Sustainability), read our “Electrical installation – wires and fuses” entry, and had the following to say:

“…one of the leading causes of EMF in the home is the way the main panel is wired. One way to prevent EMF exposure is to run wires in conduit (which you have to do anyway in Chicago), but another key item is how wires are terminated at the breaker. Basically having hot and neutral wires paired together helps cancel out any EMF.”

What is EMF?

EMF stands for Electric and Magnetic Fields or Electromagnetic Fields. The main source of EMF emissions in a home originates from the electrical wiring, wireless devices, Wi-Fi and household appliances. EMF is typically measured in units of milligauss (mG).

I was aware of the discussion around EMF pollution in homes and the alleged negative health impacts. But it is hard to find sound scientific data on this topic.

It appears that the alleged risks of EMF are taken more seriously in Europe where some government agencies have issued warnings and recommendations regarding EMF exposure.

What are the guidelines we can look to? The National Institute of Environmental Health Sciences has the following statement on its Electric & Magnetic Fields web site:

“While some of these studies showed a possible link between EMF field strength and an increased risk for childhood leukemia, their findings indicated that such an association was weak. Now, in the age of cellular telephones, wireless routers, and portable GPS devices (all known sources of EMF radiation), concerns regarding a possible connection between EMFs and adverse health effects still persist, though current research continues to point to the same weak association.”

EMF reduction and prevention

Should I worry about EMF? I like the “precautionary principle” approach, as outlined in the Minnesota GreenStar Remodeling Manual Version 2.3 (page 403):

“… if there is sufficient evidence that there could be harm from exposure to an influence and that exposure cannot be proven to be safe beyond a shadow of a doubt, then precautions need to be taken by the public to protect human exposure to that influence until safety can be firmly established.”

I was familiar with a couple of EMF reduction strategies, such as minimizing/eliminating the employment of wireless and Wi-Fi devices. Even though everybody assured me that the future is in wireless technology, I felt compelled to install flexible conduits for the hard-wiring of a cable/computer network.


But that was the extent of my EMF prevention knowledge. And this is where Jason’s comment made a difference.

He mentioned that conduit (electrical metallic tubing or EMT), which is required by the Chicago Building Code, reduces EMF emissions. It is another advantage I can add to the use of EMT, in addition to flexibility in repairs and simple mechanical grounding. Even though I hear a lot of complaints about the city’s EMT requirement, I now appreciate it even more.

Jason’s suggestion about running the hot and neutral wires paired all the way to the bus and breaker was not something we had thought about.


The hot and neutral came into the breaker panel as pairs, but then began to wander off in different directions.

Upon closer investigation, I realized that it would not take much to pair all hot and neutral wires to the breaker and bus. I turned the power off, got my tools and went to work. An hour later I completed my matchmaking task.


The best source for recommendations on EMF reduction, which I found through Jason, is the Minnesota GreenStar Remodeling Manual. In addition to the above listed strategies, proper grounding (system grounding and equipment grounding) stands out.

If you are interested in more details, I recommend to download the manual and imbibe chapter 11B. Have fun reading!

About Marcus de la fleur

Marcus is a Registered Landscape Architect with a horticultural degree from the School of Horticulture at the Royal Botanic Gardens, Kew, and a Masters in Landscape Architecture from the University of Sheffield, UK. He developed a landscape based sustainable pilot project at 168 Elm Ave. in 2002, and has expanded his skill set to building science. Starting in 2009, Marcus applied the newly acquired expertise to the deep energy retrofit of his 100+ year old home in Chicago.

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