Choosing the right horizontal unit heater is essential for maintaining comfortable temperatures in garages, workshops, warehouses, and other commercial or residential spaces. This article reviews some of the best horizontal unit heaters available, focusing on features such as heating capacity, fuel type, installation ease, and efficiency. Below is a summary table highlighting key details of the selected products to help you get a quick overview before diving into detailed reviews.
| Product | Brand | Heating Capacity | Fuel Type | Vent Type | Installation Options |
|---|---|---|---|---|---|
| Mr. Heater Big Maxx MHU80NG | Mr. Heater | 80,000 BTU | Natural Gas | Cat 1 vertical / Cat 3 horizontal | Wall mount with included brackets |
| Reznor UDXC-45 | 1HVAC | 45,000 BTU | Natural Gas | Cat 3 Z-Vent | Ceiling mount or wall mount (mounting sold separately) |
| Reznor UDXC-150 | 1HVAC | 150,000 BTU | Natural Gas | Cat 1 B-Vent | Ceiling mount or wall mount (mounting sold separately) |
| Mr. Heater 4 Inch Stainless Steel Horizontal Vent Kit | Mr. Heater | N/A (Vent Kit) | N/A | Horizontal venting | Compatible with MHU50, MHU75, MHU80 units |
| Marley 7500/10000W Horizontal/Downflow Unit Heater | Marley | Up to 34,129 BTU (approx.) | Electric | Self-contained | Floor-standing or ductwork compatible |
Mr. Heater Big Maxx MHU80NG Natural Gas Unit Heater
The Mr. Heater Big Maxx MHU80NG offers a powerful 80,000 BTU output, ideal for heating spaces up to 2,000 square feet. Designed for natural gas use, it features category 1 vertical and category 3 horizontal venting options, allowing flexibility depending on installation requirements. The package comes with two angle brackets for secure mounting and a liquid propane conversion kit to adapt to different fuel setups (thermostat, hose, and regulator are not included).
Its dimensions are 29.33 inches length, 15.50 inches width, and 26.37 inches height, suited for various commercial spaces. Operating at 120V and consuming only 2.3 amps, this unit is energy efficient. Keep in mind the need for a minimum 8-foot clearance from the floor to ensure safe operation.
Reznor UDXC-45 45,000 BTU Natural Gas Unit Heater
The Reznor UDXC-45 is a smaller capacity natural gas unit heater delivering up to 45,000 BTUs and rated with an 83% thermal efficiency. It features dual heat settings, allowing low fire output for milder days and high fire for colder conditions, providing versatile temperature control.
This heater is designed for indoor use in garages, workshops, and warehouses with quiet forced air delivery via a low static propeller fan. It supports ceiling mounting or wall mounting options, though mounting brackets are sold separately. The unit includes threaded-nut retainers at four suspension points to facilitate flexible installation. Horizontal category 3 Z-venting ensures safe gas exhaust.
Reznor UDXC-150 150,000 BTU Commercial Natural Gas Heater
The Reznor UDXC-150 is a heavyweight among horizontal unit heaters, delivering heating capacities up to 150,000 BTUs with an 83% thermal efficiency rating. It offers two adjustable heat output levels for efficient performance year-round, from chilly fall days to freezing winter temperatures.
Perfectly suited for large commercial or industrial spaces such as warehouses or factories, this natural gas unit provides quiet forced air heating with a low static propeller fan. As with the UDXC-45, it supports ceiling or wall mounting with suspension points for easy installation. The Cat 1 B-Vent horizontal venting kit ensures proper exhaust ventilation.
Mr. Heater 4 Inch Stainless Steel Horizontal Vent Kit
This Mr. Heater Horizontal Vent Kit is designed to support horizontal venting for Mr. Heater Big Maxx series models such as MHU50, MHU75, and MHU80. The kit contains all components needed for complete vent installation, including an adjustable elbow, adapter, b-vent pipes, wall thimble, roof flashing, storm collar, and vent cap.
Its stainless steel construction ensures durability and corrosion resistance, suitable for long-term use in various weather conditions. The thimble can expand about 4 inches through wall installation, with overall dimensions of 6.5 inches tall, 13.5 inches wide, and 37 inches deep. Weighing 13 lbs., it facilitates secure and compliant venting in horizontal formats.
Marley 7500/10000W 208/240V Horizontal/Downflow Unit Heater
The Marley 7500/10000W Horizontal Unit Heater is an electric heating option ideal for industrial spaces requiring clean and quiet heating. It features a powerful pull-through air design that ensures even heat distribution with a compact footprint suitable for floor-standing or ductwork integration.
Engineered with a sturdy metal body, this unit includes a linear thermal cutout that automatically protects the heating element, enhancing safety. A 24V control transformer is included on most models for safer and easier temperature adjustments. This heater offers versatility with horizontal or downflow configurations, making it suitable for a variety of commercial environments.
Buying Guide for Horizontal Unit Heaters
When selecting a horizontal unit heater, several factors contribute to optimal performance and suitability for your space. Consider the following points to make an informed purchase:
- Heating Capacity (BTU Output): Match the unit’s BTU rating to the size of the area you want to heat. Smaller spaces require lower BTU, while larger commercial or industrial areas need higher outputs.
- Fuel Type: Decide between natural gas, propane, or electric heaters based on fuel availability, installation cost, and operational preferences. Natural gas units are common for large spaces, while electric heaters suit smaller or indoor environments.
- Ventilation Type: Horizontal unit heaters may use different venting categories, including Cat 1, Cat 3, or B-Vent. Check local codes and installation requirements to ensure compatibility with your building.
- Installation Flexibility: Look for heaters offering multiple mounting options such as ceiling, wall, or floor. Easy installation and included mounting brackets can save time and expenses.
- Efficiency and Safety Features: High thermal efficiency ratings reduce fuel consumption. Safety features like automatic shutoff or thermal cutouts prevent overheating and ensure safe operation.
- Noise Level: For workspaces, quieter models with low static fans help maintain a comfortable environment without excessive noise disruption.
- Durability and Build Quality: Preference should be given to products with corrosion-resistant materials and robust construction to withstand harsh conditions.
- Vent Kits Compatibility: If your heater requires external venting, check for compatible vent kits that are easy to install and made from durable materials.
Assessing these parameters will help you select the best horizontal unit heater tailored to your heating needs and space characteristics.