Category Archives: electrical

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.

EMF

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.

EMF-01

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.

EMF-02

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!

1st floor light fixtures

With a rehab or remodeling project, whether it’s green or not, it is easy to spend insane amounts of money on decorative stuff – such as light fixtures.

I did some window shopping for Energy Star certified lights in the larger home improvement stores. It added up very quickly! I think I must have been three or four light fixtures in when I realized that this is not going to work with our 1st floor lighting budget.

This is where the salvaged materials option become really handy!

You see, it’s not only about doing “the right thing;” reducing waste, keeping materials out of the waste stream, repurposing stuff, you name it. It is also about hard, cold cash – plain and simple!

Because you can’t really plan for the purchase of salvaged and used lights (you never know what you’ll find when and where), I drew up a quick light fixture schedule. It reminded me of what lights I need where, and helped me to keep track of the purchases.

I tried Craigslist, but didn’t find anything fitting. My next stop was the ReBuilding Exchange. I went home with four nice ceiling lights perfect for our the kitchen at a total price tag of $40.00. Even better – these are Energy Star fixtures with the GX 24 base (a four pin base for CFL bulbs). In a store, I would have paid at least $40.00 for one light alone.

But we need a whole lot more fixtures. So one Saturday, we went from one ReStore in the Chicago area to the next, scouting for materials.

 

It was worthwhile the driving around. We came back home with 12 lights at a total cost of $125.00. That included a fancy pendant light for the dining room at only $25.00.

What I didn’t expect is that almost half of all lights purchased were Energy Star fixtures with either the GU 24 or the GX 24 pin base. The standard Edison screw base would have been OK – we will use CFL or LED bulbs no matter what. The nice thing with the GU 24 or GX 24 pin bases is that one cannot use incandescent bulbs – just in case someone goes crazy and wants to heat the rooms with incandescent bulbs!

We had no luck finding lights for the front door on our scavenger hunt. That said, we were looking for something pretty specialized: Nice looking, dark sky. affordable lights with motion and dusk-to-dawn sensors. I bought them new, in the store, for $120.00 – almost as much as I paid for the 12 used lights.

The ceiling fans for the library, living room, and two bedrooms are not something we will find in the used or salvaged market either. We decided for a super efficient Emerson model. But that is a story for another post.

Electrical installation – reuse

Let’s return to the electrical installation for a moment and talk about resource efficiency.

We were able to salvage a whole lot of EMT conduit during the deconstruction of the basement, 1st and 2nd floor. These included straight pieces of EMT at various length and a lot of 90 degree bends. The image below shows a small portion of the salvaged EMT.

Our first electrical contractor who did the basement installation had no interest in using any of it. Percy Harrison, our electrical contractor for the 1st floor, didn’t blink and was more than happy to use what we had salvaged. I am glad to report that all the salvaged EMT conduit was used up.

With all the wires on the 1st floor pulled and connected to the panel, I am getting awfully close to installing drywall. That means I have to install the appropriate mud rings on all the electrical boxes first.

I had noticed on my many visits to the ReBuilding Exchange or the various Habitat for Humanity ReStores that they sometimes have a good selection of salvaged mud rings.

The key word here is “sometimes.” I had known for a while that I will need a lot of mud rings, and thus started buying them up – mostly at the ReStores. This way I got about 90% of what I needed as salvaged material at about half price, compared to new materials.

And while I was on that shopping spree, I made sure to also stock up on cover plates. Again, all salvaged materials. I love spending my money in the re-use economy!

Electrical installation – wires and fuses

A couple of things have become handy:

  1. Having a circuit breaker plan, i.e. knowing what area of the 1st floor is fed by what kind of fuse.
  2. My early lessons on wire terminology in which I learned that a 20 amp circuit requires 12 AWG (American Wire Gauge) wire, whereas a 15 amp circuit only requires a 14 AWG wiring.

That knowledge makes the upcoming task of pulling the wire a little easier and more organized. Still, I decided that it would be wise to let our experienced electrician (Percy Harrison) lead the task and reserve the observer and helper role for myself.

Pull or push?

I had bought a 60 foot fish tape a while back, knowing that I will need it one day to pull wire. Imagine my surprise when Percy began the job with no fish tape in sight. He actually did not pull the wire, he just folded the ends over and pushed it!

This is way faster than tinkering around with the tape. That said, there is a limit to pushing the wire. Once the conduit gets crowded, or with a long conduit run that has a lot of bends, the fish tape is the only way to go.

Splicing

It didn’t take long for me to get overwhelmed by the amount of wires sticking out each electrical box.

Power to each room is provided with a hot (typically a black) and a neutral (a white) wire that arrives in the ceiling box. From there connecting wires are run to each light, light switch and outlet.

Percy seem to know exactly which wire was for what and began to splice them together. I didn’t go near a ceiling box, but rather tested my splicing skills at electrical boxes for outlets and light switches, where I could count the number of wires on one hand.

Labeling

Because I felt it was nearly impossible to keep track of what wire did what and went where, I decided it was a good idea to label them with little wire tags. I think Percy was amused by my outbreak of paranoia, although he didn’t show it.

 

Was this really necessary? With an electrical layout that is intuitive, follows standard professional practices, and is well organized, probably not. The upside of labeling all wires was that I really began to understand the system and I now know it inside-out.

Last connections

With everything spliced up and all wires labeled, there is only one spot left that may appear overwhelming: the circuit breaker panel. Here we still have have a seemingly unorganized jungle of wires.

I knew how many and what kind of fuses to get, because we had planned the load management prior to pulling the wires. We slipped each fuse into its slot, making sure that we kept the system balanced across the two phases.

Connecting the wires to each fuse turned out to be straightforward, thanks to my labeling effort.

It’s time for me to get some mud rings for the electrical boxes, and hopefully, before too long, install the lights, outlets and switches. Although, there is that thing called drywall that I first have to take care of.

Electrical layout – built-in flexibility

The programming of each room and space drives the electrical layout.

How will we use the room? What big furniture items will go where? What electrical devices are needed and where are they needed?

Although answering these questions was a little more complex than I expected, the decision making process was relatively straightforward – except for two of the bedrooms.

It seemed obvious how each bedroom should be arranged, and we installed outlets, reading lights, and light switches accordingly.

That said, I could not ignore that there were alternative arrangements, which one may prefer in the future. Actually, it just comes down to how many options there are to place the bed.

Should we decide to move the bed around, it would be nice if everything else could move with it. Mainly reading lights and conveniently placed outlets at each side of the bed, one on a kill switch, the other not.

At one point it dawned on me that this could be arranged by installing a couple of additional electrical boxes and a few more feet of conduit.

With this built-in flexibility, we have our reading lights, light switches and outlets handy, no matter whether we decide the put the bed one way or the other.

The electrical boxes for the set of “in case we need them” reading lights can be covered with a plate, but will be available and ready to use if we need to move the bed around.