Finding the right garage heater with vertical venting matters when you need efficient exhaust routing, safe combustion, and installation flexibility. Below is a quick comparison table of the selected products reviewed in this article, followed by detailed sections covering features, vent compatibility, mounting, and suitability for garage and shop spaces.
| Product | Fuel / Type | BTU / Power | Venting |
|---|---|---|---|
| Mr. Heater Big Maxx MHU80NG | Natural Gas | 80,000 BTU | Category 1 vertical / Cat 3 horizontal |
| Reznor UDXC-100 (Propane) | Propane | Up To 105,000 BTU (two levels) | Vertical Cat 1 B-Vent Kit compatible |
| Reznor UDXC-45 (Natural Gas) | Natural Gas | 45,000 BTU (two levels) | Vertical Cat 1 B-Vent Kit compatible |
| Comfort Zone CZ220BK Ceiling Mount (Electric) | Electric | 5,000 W (240V) | Hardwired ceiling mount (no combustion venting) |
| CTSC 10000W Electric Garage Heater | Electric | 10,000 W (240V) | Hardwired ceiling/wall (no combustion venting) |
Content Navigation
- Mr. Heater F260560 Big Maxx MHU80NG Natural Gas Unit Heater
- Reznor 100,000 BTU UDXC-100 Propane Unit Heater
- Reznor UDXC-45 Natural Gas Unit Heater
- Comfort Zone CZ220BK Hard-Wired Ceiling Mount Electric Heater
- CTSC 10000W Electric Garage Heater Hardwired Fan-Forced
- Buying Guide: Choosing A Vertical-Venting Garage Heater
Mr. Heater F260560 Big Maxx MHU80NG Natural Gas Unit Heater
The Mr. Heater Big Maxx MHU80NG is a high-capacity natural gas unit heater designed for garages, workshops, and similar spaces. It lists 80,000 BTU heating performance and is intended to cover up to 2,000 sq. ft. according to the manufacturer notes. The unit ships with two angle brackets and a liquid propane conversion kit, though thermostat, hose, and regulator are not included.
Key installation details include minimum 8 ft. clearance from floor to base of unit and electrical input of 120 V at 2.3 amps. Venting compatibility is important for vertical exhaust routing: the product is specified for Category 1 vertical venting as well as Category 3 horizontal, indicating it supports classic B-vent vertical chimney applications in many garage installations. The compact footprint (approximately 29.33” L x 15.50” W x 26.37” H) suits ceiling or high wall mounting positions commonly used for garage heaters.
Reznor 100,000 BTU UDXC-100 Propane Unit Heater
The Reznor UDXC-100 is a commercial-style propane unit heater designed for ceiling or suspended mounting in garages, warehouses, and shops. Its rated capacity is listed as 105,000 BTU with two heating output levels—useful for modulating heat between milder and colder days. The product listing highlights an 83% thermal efficiency rating.
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Reznor includes features for mounting flexibility: threaded-nut retainers at four suspension points for ceiling mounting or alternative bracket setups. For venting, the listing calls out a Vertical Cat 1 B-Vent Kit, indicating the unit is compatible with classic category 1 vertical vent piping. That makes the unit applicable where vertical exhaust through a roof or chase is required. The unit is described as quiet forced-air with low static propeller fan characteristics, helpful for shop environments.
Reznor UDXC-45 Natural Gas Unit Heater
The Reznor UDXC-45 is the lower-capacity sibling in the UDXC family, rated for 45,000 BTU with dual output levels for light and heavier heating needs. The unit lists an 83% thermal efficiency, and is positioned for indoor garage or shop use.
Mounting is flexible with suspension points for ceiling installations. For vertical venting needs, the listing references compatibility with a Vertical Cat 1 B-Vent Kit, allowing vertical flue routing through roofs or chase systems where Category 1 venting is accepted. This model suits smaller garages, single-bay shops, or workshop spaces where a full-size heater would be oversized.
Comfort Zone CZ220BK Hard-Wired Ceiling Mount Electric Heater
The Comfort Zone CZ220BK is a ceiling-mounted, hard-wired electric fan-forced heater intended for garages and workshops that prefer no-combustion heating. This 5,000 watt, 240 V model offers a compact footprint and uses louvers and an adjustable mount angle for directed airflow.
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Because this is an electric unit, vertical combustion venting is not applicable. Instead, it is often chosen where venting through a roof or wall is not possible or where code/air quality concerns preclude combustion appliances. The heater emphasizes heavy-gauge steel construction and overheat protection, and is ETL compliant for safety certification in many installations.
CTSC 10000W Electric Garage Heater Hardwired Fan-Forced
The CTSC 10000W electric heater is a high-power hardwired option for larger garages and shops that need fast, distributed heat without combustion exhaust. It lists multiple heat settings (10,000 W / 7,500 W / fan only), digital thermostat control, remote control, and an ECO function.
The product notes a voltage display to help troubleshoot common installation issues and a sturdy SPCC cold-rolled steel construction with overheat protection. Like other electric ceiling or wall-mounted heaters, vertical venting is not relevant; instead, it provides a simple alternative when Category 1 B-vent routing or gas hookups are impractical or not permitted by code.
Buying Guide: Choosing A Vertical-Venting Garage Heater
Vertical venting affects heater selection, installation costs, and compliance. This guide highlights the key considerations when comparing gas unit heaters (vertical vent) against electric ceiling/wall options.
Venting Type And Code Compatibility
- Category 1 (B-Vent): Common for natural-draft gas appliances using vertical venting through a roof or chase. Ensure the heater listing explicitly supports Category 1 vertical venting.
- Category 3 / Power Venting: Some units may allow horizontal power-vented exhaust; check manufacturer specifications for allowed vent categories and termination clearances.
- Local Codes: Always verify local building and fuel-gas codes. Roof penetrations, chase construction, and clearances to combustibles are code-sensitive and may require permits or licensed installers.
Fuel Type: Natural Gas vs Propane vs Electric
- Natural Gas and Propane unit heaters often require combustion venting (vertical/horizontal). They provide high BTUs and lower operating cost when fuel is available.
- Propane units are versatile where natural gas lines are absent, but fuel storage and delivery are required.
- Electric ceiling or wall heaters avoid combustion venting and indoor air quality issues, but electric operating costs and availability of 240 V hardwiring should be considered.
BTU And Coverage
- Match heater capacity to garage size and insulation level. Higher BTU (or wattage) is necessary for uninsulated, high-ceiling spaces.
- For gas units, manufacturers typically list approximate coverage area—use that as a starting point and adjust for ceiling height and draftiness.
Mounting And Clearance Requirements
- Ceiling-mounted gas unit heaters require adequate clearance to combustibles and often a minimum floor-to-unit clearance (example: Mr. Heater lists minimum 8 ft.).
- Suspension points and bracket options affect mounting flexibility; confirm included hardware and any additional mounting kits required.
Venting Path And Termination
- Plan the vertical vent route early. Roof penetrations, storm collars, and flashing add cost and require precise installation.
- Ensure the venting kit matches the unit’s category rating (e.g., Category 1 B-Vent Kit) and that chimney height and clearances meet the manufacturer’s instructions.
Efficiency And Controls
- Look for efficiency ratings and multi-stage outputs for more precise heat control—Reznor UDXC series lists dual output levels and an 83% thermal efficiency figure.
- Electric models may offer digital thermostats, timers, and remote or smart controls for zone heating and energy savings.
Safety And Certifications
- Check for ETL, CSA, or ANSI certifications for both gas and electric units. Overheat protection and thermal cut-outs are essential.
- Combustion units should have proper clearances and recommended installation by qualified professionals to reduce carbon monoxide and flue-gas risks.
Installation And Maintenance Considerations
- Gas unit heaters typically require a licensed installer for fuel connection and venting. Expect periodic inspection of burners, flue, and vent components.
- Electric hardwired units require correct voltage and dedicated circuits; the CTSC model includes a voltage display to aid troubleshooting.
- Plan routine maintenance access and filter or fan checks for forced-air models.
Comparison Perspectives
- Cost To Operate: Gas often wins for running cost if fuel is cheap and available; electric is simpler but can be more expensive depending on local electricity rates.
- Installation Complexity: Electric units are typically less complex to install when 240 V is available. Gas vertical venting adds complexity with roofing penetrations and vent chimney work.
- Air Quality: Electric units avoid combustion byproducts inside the building; gas units must be vented correctly to prevent indoor contamination.
- Noise And Air Movement: Forced-air gas units and electric fan heaters move air; review fan noise specifications if quiet operation is important.
When selecting a vertical-venting garage heater, balance venting feasibility, fuel availability, safety requirements, and operating cost. Use manufacturer venting guidance and local codes to ensure a compliant installation.
Tips for Getting the Best HVAC Prices
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