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BAYHEAT
G-018 · REV 2 · CHECKED 2026-10-09 · MODEL v1.0.2 ▾

Drafted with AI assistance. Numbers computed by model v1.0.2 or sourced. Human review: pending (BayHeat editorial desk). Licensed review: no page-specific approval recorded.

Technical review: no page-specific licensed approval recorded.

M measured · C computed · S spec · R reference · E estimate

Ceiling-mount garage heaters

A 5 kW ceiling class () needs an wall clearance, a ceiling under , and at least of headroom below it. A 7.5 kW shop unit adds a side and back clearance. Both run on a dedicated 240 V circuit sized off the nameplate, not a guess.

Model pick · spec-based

Comfort Zone CZ220 5,000W ceiling heater5.0 kW · 240 V / 30 A

A 5 kW ceiling unit on a 30 A circuit: the CZ220. Sealed and insulated, it covers our example 2-car garage.

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Check price on Amazon
Paid linkSee mounting height and clearances ↓

Manual: not where gasoline, paint or flammable liquids are used or stored. Indoors only, in a dry space free of combustible dust. Source ↗

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What a ceiling heater in this spot actually has to cover

For BayHeat's standard worked example — a 24×24 ft attached 2-car garage in Chicago, R-13 walls, one uninsulated steel door — the design load comes to (), grade D.

Ceiling
34%
Air leaks
24%
Big door
23%
Slab edge
9%
Walls
8%
Windows
3%
House wall
-3%
Service door
2%
FIG. 1 Where your heat goes, sorted largest first.
Heat escapesYour garage: DHolds heat

A single 5 kW ceiling unit () covers about of that load on its own — it won't keep up in the coldest week without a second unit or a lower-U ceiling. A 7.5 kW shop unit () gets closer, at about .

54% of your load
80% of your load
Bringing the ceiling to R-30 and sealing the envelope drops this same garage to about (), grade B — inside what a single 5 kW ceiling unit can hold. See how to insulate a garage in payback order →

Mounting height, throw, and clearances from the manuals

A ceiling heater's numbers come from its own manual, not a rule of thumb. The two 5 kW units below use different clearance figures even though they put out nearly the same heat:

SpecCZ220 (5 kW)DR-975 (7.5 kW)
Output
Rated throw (manual says approximate)—
Clearance from wall—
Clearance from floor
Max ceiling height—
Clearance, sides—
Clearance, back wall—

A dash means the manufacturer's manual doesn't publish that figure for this unit — don't assume it matches the other row.

Federal residential building code adds a floor: ( also applies — a hardwired heater is a continuous load, so the breaker and wire are sized at 125% of the actual draw, not the nameplate amps alone). Your electrician and your local code edition govern.

The two ceiling classes, and what each is built for

240V CEILING · 5 KW

Comfort Zone CZ220 / Fahrenheat FUH54

at , on a . Best for an insulated 2-car garage, or a bare one once it's sealed.

Manual: not where gasoline, paint or flammable liquids are used or stored. Indoors only, in a dry space free of combustible dust.

Check CZ220 price on Amazonor the FUH54 ↗

Price class: $$ / $$$

240V CEILING/WALL SHOP · 7.5 KW

Dr. Infrared DR-975

at , on a . Fits a larger or leakier 2–3 car garage without doubling up units.

Manual: “WARNING – RISK OF FIRE, DO NOT USE AS A RESIDENTIAL OR HOUSEHOLD HEATER.” Also not where gasoline, paint or flammable liquids are used or stored. Ask Dr. Infrared whether your garage counts as residential before you buy.

Check price on Amazon

Price class: $$$

  • Why not a 120V portable utility heater (1,500W)? A cord-and-plug portable isn't rated for continuous or unattended heating -- a hardwired, thermostat-controlled class is built for that instead.
  • Why not a Portable propane radiant heater with ODS (Buddy/Big Buddy)? A propane radiant unit is never rated to hang from a ceiling — it's a floor-standing, attended-use tool, not a fixed installation.

Safety at the point of installation

General information. Your electrician, gas fitter, local code and the heater's manual govern.

Both ceiling classes above are electric resistance, not combustion — but the 18 in ignition-source floor still matters for any garage that also has, or might later get, a fuel-fired appliance sharing the space. Check Can I run this heater in my garage? → for a verdict specific to your circuit and what's stored in the garage.

Next step

Run your own garage through the planner → for a load, grade and circuit sized to your dimensions, not the worked example above.

Related

Sources

  1. [1] Comfort Zone CZ220 Series ceiling mounted heater owner's manual, Comfort Zone (Lowe's copy). Retrieved 2026-10-09.
  2. [2] Fahrenheat FUH54 / FUH54C installation, operation and maintenance instructions (5200-11195-000), Marley Engineered Products. Retrieved 2026-10-09.
  3. [3] Dr. Infrared Heater DR-975 owner's manual, Dr. Infrared Heater. Retrieved 2026-09-30.
  4. [4] International Residential Code, 2021, ICC. Retrieved 2026-09-25.
  5. [5] NFPA 70, National Electrical Code, 2023, NFPA. Retrieved 2026-09-25.
Size my garage — 60 s