Upgrade old electrical wiring

Healthy HouseTM TechTip

Knob-and-tube wiring

Knob-and-tube wiring

Houses with older wiring tend to have elevated EMF.

Knob-and-tube wiring was a early method of electrical wiring that was common to North America from the 1880s to the 1930s. Many older houses are still using this type of wiring today. Houses with this type of wiring usually have higher EMF as compared to houses wired according to current electrical standards.

Knob-and-tube wiring does not inherently contain a grounding wire, which means that you cannot use three prong appliances with this type of wiring. Many older homes with knob-and-tube have been improperly upgraded to support a grounded receptacle. In many of these instances, the grounding conductor is energized with voltage. This voltage on the grounding conductor creates an increased electric field radiating from the device plugged into the improperly grounded receptacle.

Knob-and-tube wiring is designed to contain significant separation of the hot and neutral conductors for heat dissipation. This separation causes elevated magnetic fields in the house.

Even in newer houses, the electrical system can develop problems as the system ages. Circuit breakers and GFCI receptacles can fail with age. Circuit breakers should be inspected periodically to ensure that there are no signs of corrosion or debris buildup. At any sign of corrosion, the circuit breaker should be replaced. When a circuit breaker or GFCI protection device fails, the switching contacts can remain closed and the device continues to provide power—providing no safety protection, which can result in serious injury or even death.

When replacing electrical wiring, consider using a metalized conduit. When instrumented correctly, metalized conduit will block the electric field coming from the hot conductor that is energized. Elimination of the electric field will result in a lower body voltage as compared to alternative wiring containing a non-metalized plastic or vinyl jacket.