Cejas Cooling & Construction

Between Sparks and Silence

Between Sparks and Silence: Inside Electric Heat’s Quiet Revolution

Electric heating doesn’t roar like a furnace or churn like a compressor. It hums. Quiet. Subtle. Precise. It doesn’t need a fuel line or flue gas analyzer. It’s pure resistance, wire to heat, motionless and immediate. And in the right place, it’s more than enough—it’s the secret weapon of off-grid cabins, condo towers, and cities trying to decarbonize.

Efficiency and Operating Costs of Electric Heat

Electric resistance heating is 100% efficient at the point of use. All the electricity gets converted into heat. Sounds great, right? Until you compare energy costs. In many areas, electric rates are 2 to 3 times higher than natural gas or oil. So even though it’s perfectly efficient, it can be more expensive to run long-term—unless you’re in a region with cheap or renewable electricity.

Portable and Radiant Electric Heaters

  • Portable Units: Space heaters, fan-forced units, and radiant disks. Plug-and-play, good for spot heating. Often include thermostats, tip-over protection, and overheat cutoffs.
  • Radiant Panels: Quiet, sleek, and often installed in ceilings or floors. Use infrared waves to heat objects and people directly, like the sun. No fans, no moving parts, just warmth.

Electric Baseboard, Unit, and Wall Heaters

  • Baseboard Heaters: Convection-based. Cool air enters the bottom, heats through electric coils, rises naturally.
  • Wall Heaters: Fan-forced, faster response. Installed flush into walls, used in bathrooms or hallways.
  • Unit Heaters: Typically larger, often in garages or warehouses. Fan-driven, direct control.

All three are controlled by line-voltage thermostats. No transformers needed. Switch opens and closes the 240V directly.

Why Use Electric Boilers?

  1. No Chimney Required: Venting not needed—perfect for apartments or tight urban construction.
  2. Compact Size: Small footprints fit in closets or utility panels.
  3. Clean Operation: No combustion. No CO. Perfect for areas with strict emissions rules or hydronic retrofits.

Electric Forced-Air Furnace Operation

Electric furnaces use heating elements, blowers, and sequencers:

  • Heating elements (usually nichrome coils) heat up fast when voltage is applied
  • Blower circulates air across coils into ductwork
  • Sequencers stagger element activation to avoid high inrush current

Controls: Thermostats, Sequencers, and Contactors

  • Thermostat calls for heat
  • Sequencer (a time-delay relay) brings elements on in stages
  • Contactor is the traffic cop, sending power to the right elements or blower motor

Think of it like a symphony: the thermostat cues the conductor (sequencer), who signals the instruments (heating elements) in proper timing.

Wiring Diagrams: Two Styles

  1. Ladder Diagrams: Show control logic. Each rung is a circuit.
  2. Pictorial Diagrams: Show physical layout of components.

Ladder = logic. Pictorial = location.

Power-Passing vs Power-Consuming Devices

  • Power-Passing: Switches, contactors, thermostats. They route electricity.
  • Power-Consuming: Heating elements, blower motors. They convert electricity into work (or heat).

Example: Thermostat sends power to sequencer (passing), which feeds the heating element (consuming).

Tracing the Circuit in an Electric Furnace

Start at L1 and L2. Follow through the thermostat. Into sequencers. Out to elements and blower. Back to L2. Every component should complete the path, or you’ve got an open circuit.

Sensible Heat Formula

Q = 1.08 x CFM x ΔT

  • Q = BTUs/hour
  • 1.08 = constant for air at sea level
  • CFM = Cubic feet per minute of airflow
  • ΔT = Temperature rise across furnace

Example:

  • 800 CFM
  • 50°F rise
  • Q = 1.08 x 800 x 50 = 43,200 BTU/h

Preventive Maintenance for Electric Heating

  • Check heating element resistance
  • Inspect sequencer operation
  • Verify contactor engagement
  • Inspect blower motor bearings and amp draw
  • Clean dust and debris from cabinet and element fins

Basic Troubleshooting Tests

  • Continuity Checks: Use multimeter to confirm heating elements are intact
  • Voltage Checks: Ensure line voltage is present at terminals
  • Amp Draw: Verify elements are drawing expected current
  • Sequencer Timing: Confirm delay staging is happening properly

Electric heat is simple on paper but nuanced in the field. It’s invisible power flowing through wires that don’t roar or rattle—just deliver comfort without drama. When it fails, it’s quiet. When it works, it’s invisible. And if you don’t understand the circuit, you’ll be chasing ghosts.