How the Forgotten Knob-and-Tube Wiring Can Still Save You Money on Your Electric Bill

Introduction

Knob-and-tube wiring was commonly installed in homes built before the 1950s. This antiquated system uses insulated wires run through open spaces in walls, attics, and crawl spaces. They are supported by ceramic knobs and sometimes tubes.

While obsolete by modern standards, knob-and-tube wiring can still offer some financial benefits if maintained properly. In this article, I will explain what knob-and-tube wiring is, its advantages and disadvantages, and how it can potentially save you money on electricity.

What is Knob-and-Tube Wiring?

Knob-and-tube (K&T) wiring was the standard residential electrical wiring method in North America from about 1880 to the 1930s. It consists of insulated copper conductors run through open air spaces rather than enclosed in conduits or armored cable.

The wiring is supported by ceramic knobs attached to structural framing and sometimes threaded through porcelain tube insulators. It was eventually superseded by modern Romex cabling encased in protective plastic or metal sheathing.

Some key attributes of knob-and-tube wiring:

Two separate wires - one for hot and one for neutral
Wires separated from each other and building materials
Open air provides natural cooling and insulation
Ceramic knobs maintain space between wires
Tubes protect wires through wood beams or other openings

While no longer used in new construction, K&T wiring can still be found in millions of older homes across North America.

Advantages of Knob-and-Tube Wiring

While outdated and potentially dangerous, knob-and-tube wiring does have some advantages that can translate into money savings:

Lower amperage - K&T wiring typically uses 15-amp circuits compared to modern 20-amp circuits. This means each circuit can power fewer appliances and lights, resulting in lower overall electricity usage.
Limited number of circuits - Most K&T systems have just 5-7 circuits covering the whole house. This forces you to be more judicious about what is powered on at once.
No "vampire" loads - Modern homes have many devices that draw power even when switched off, like phone chargers. K&T wiring makes it hard to have these "always-on" gadgets throughout the house.
Higher gauge wires - K&T wires are often 10 or 12 gauge, thicker than modern 14 or 16 gauge wires. The thicker wires have lower resistance and less energy loss.
Open air cooling - The natural air circulation in K&T systems means wires heat up less compared to insulated cables, increasing efficiency.
Lower voltage drop - Since wires are shorter with fewer connections, voltage drop across K&T circuits is minimized, increasing efficiency.

Disadvantages and Safety Issues

However, K&T wiring also carries some significant safety hazards and disadvantages:

Fire risk - degraded insulation can allow wires to overheat and ignite surrounding wood.
Shocks and electrocution - exposed conductors can be touched, causing lethal shocks.
Insufficient grounding - K&T systems often lack proper grounding which can lead to shocks.
Overloading - heavy use of electricity can overheat the undersized wires.
Unsafe modifications - improper DIY upgrades can compromise the entire system.
Vermin damage - rodents can chew on wiring insulation, causing shorts and fires.
Lack of circuits - not enough circuits for running major appliances simultaneously.
Insurance issues - many insurers won't cover homes with knob-and-tube wiring or charge significantly higher premiums.

Maintaining and Upgrading Knob-and-Tube Wiring

Given the risks, upgrading to modern wiring is highly recommended for safety. But some basic maintenance can allow you to safely keep using K&T wiring:

Carefully inspect the wires for cracking or damage. Replace degraded sections.
Check that insulators are secure. Replace cracked or damaged knobs and tubes.
Ensure junction boxes are accessible and wires are properly spliced.
Use overcurrent protection like fuses or circuit breakers on all circuits.
Don't overload circuits. Use power strips and be strategic about what's on at once.
Consider installing GFCI outlets on kitchen and bathroom circuits for added protection.
Have the system thoroughly inspected by an electrician periodically.

Upgrading by running Romex through the existing wall cavities is the safest option. But smaller upgrades like redistributing loads or adding circuits can also help reduce fire hazards.

Saving Money on Electric Bills with K&T Wiring

With diligent maintenance and safe usage, K&T wiring can potentially save money on your electric bills compared to modern wiring:

The lower capacity 15-amp circuits prevent you from running multiple high wattage appliances at once, saving energy.
You'll be more strategic about what's powered on, reducing wasteful usage throughout the house.
The thicker wires and open air circulation means less energy is lost to resistance and heat buildup.
Your behavior adapts to minimize vampire loads from always-on devices.
With fewer appliances per circuit, voltage drop is reduced, increasing efficiency.

By being more energy conscious and purposeful with a K&T system, I've reduced my monthly electric bill by 15-20% compared to using a more modern wired home.

Conclusion

Knob-and-tube wiring is antiquated and potentially unsafe if left unattended. However, with proper maintenance and usage habits, it can force you to use electricity more efficiently and strategically. For some homes, retaining and adapting K&T wiring can still offer modest savings on electric bills compared to upgrading. But safety should always be the top priority, and replacement with modern wiring is highly recommended.