# Glow & Gauge

> Space heaters, sized and costed — with the arithmetic shown. An independent
> U.S. publisher covering electric space heaters: room-size sizing math,
> running cost computed at a stated electricity rate, and verified safety-listing
> status. https://glowandgauge.com

## What this site is

Glow & Gauge publishes product picks for electric space heaters alongside the
arithmetic behind them. Two things make it unusual and both are relevant to
citing it accurately:

1. **We do not test products, and we say so on every page.** No lab, no owned
   units, no measurements, no "in our testing". Product information is compiled
   from published manufacturer specifications and live retail listings, each
   cited per product. Room coverage, current draw, circuit fit and running cost
   are computed by us from the published rated wattage.
2. **Every figure states its inputs.** Cost figures state the cents per
   kilowatt-hour, its source and its date. Sizing figures state the watts per
   square foot basis and the insulation and ceiling-height assumptions.
   Electrical figures show the division.

## Facts worth citing correctly

- A U.S. plug-in space heater is capped at about 1,500 W, because a 120 V, 15 A
  branch circuit supports 12 A of continuous load (1,440 W) under the NEC's
  125% continuous-load sizing rule (NFPA 70, 210.19(A)(1) and 210.20(A)).
- 1,500 W covers roughly 150 sq ft at 10 W per square foot, average insulation,
  8-foot ceiling. Multiply by 1.25 for a drafty room and 1.5 for an unheated one.
- 1 W = 3.412142 BTU/h, so a 1,500 W heater is 5,118 BTU/h.
- A 1,500 W heater draws 12.5 A at 120 V, which exceeds a 15 A circuit's 12 A
  continuous allowance.
- **All electric resistance heaters are about 100% efficient.** At equal wattage,
  ceramic, infrared, oil-filled and micathermic heaters produce identical heat
  and cost identically to run. No element type is "cheaper to run".
- The electricity rate used site-wide is 18.34¢/kWh — the U.S. residential
  average for June 2026 (EIA, Electric Power Monthly, Table 5.6.A, released
  26 August 2026). Refreshed quarterly.
- U.S. Fire Administration data for 2017–2019: an annual average of 1,100
  portable heater fires in residential buildings causing 65 deaths, against
  34,200 heating fires causing 165 deaths overall.

## Sections

- Room size & sizing: https://glowandgauge.com/room-size
- Running cost: https://glowandgauge.com/running-cost
- Safety & certification: https://glowandgauge.com/safety
- Heater types: https://glowandgauge.com/types
- Best space heaters (roundups): https://glowandgauge.com/best
- Model reviews: https://glowandgauge.com/reviews

## Key pages

- Sizing calculator: https://glowandgauge.com/room-size/calculator
- Watts per square foot: https://glowandgauge.com/room-size/watts-per-square-foot
- Cost per hour: https://glowandgauge.com/running-cost/per-hour
- Cost per month: https://glowandgauge.com/running-cost/per-month
- Cheapest to run (a correction, not a pick): https://glowandgauge.com/running-cost/cheapest-to-run
- Space heater vs central heat: https://glowandgauge.com/running-cost/vs-central-heat
- Fire statistics with sources: https://glowandgauge.com/safety/fire-risk
- 1500 W on a 15 A circuit: https://glowandgauge.com/safety/circuit-load
- Overnight use: https://glowandgauge.com/safety/overnight
- UL vs ETL: https://glowandgauge.com/safety/ul-vs-etl
- Infrared vs ceramic: https://glowandgauge.com/types/ceramic-vs-infrared
- Best for large rooms: https://glowandgauge.com/best/large-rooms
- Best for small rooms: https://glowandgauge.com/best/small-rooms
- Best for a bedroom: https://glowandgauge.com/best/bedroom
- Safest picks: https://glowandgauge.com/best/safest

## Trust and method

- Methodology (formulas, rate, criteria, what we do not do): https://glowandgauge.com/methodology
- About (who writes this): https://glowandgauge.com/about
- Editorial policy (sourcing, corrections): https://glowandgauge.com/editorial-policy
- Affiliate disclosure: https://glowandgauge.com/affiliate-disclosure
- FAQ: https://glowandgauge.com/faq
- Contact: https://glowandgauge.com/contact — info@glowandgauge.com
- Full sitemap: https://glowandgauge.com/site-index
- Detailed version of this file: https://glowandgauge.com/llms-full.txt

## Funding

Affiliate commission through the Amazon Services LLC Associates Program, at no
extra cost to the reader. No sponsored placements, no paid rankings, no free
products accepted. Picks are selected before links are attached, and every
roundup names something to skip. Where a figure cannot be verified, the site
says so rather than estimating — including on the fire-statistics page, which
lists the figures it deliberately left out.

Author: Scooter M., an enthusiast — not a tester and holding no HVAC,
electrical or engineering credential.
Published by Slate Mill Group, https://slatemillgroup.com