Jean-Michel Roy has some experience with Lennox Commercial’s LF25 Unit Heater, on which the DDA judges bestowed the Gold medal for the Light Commercial category. Roy, who is the president of Laltech Climatisation in St-Joseph-du-Lac, Quebec, Canada, can sum up his team’s relationship with the equipment in few words.
“The installation of Lennox LF25 heating units are quick and easy. Service and repairs are also easy. We install the LF25 units because they are reliable for the long term.”
The LF25 evolved from two years of research and development, a teardown of the manufacturer’s LF24 models, and technician feedback on potential improvements.
Three specific design components impressed the panel with regard to contractor use. What the company calls “180 Installation Capability” on the 030-105 kBtuh models allows the technician to install the unit heater upside down. This increases installation flexibility significantly by preventing having to pipe everything to the other side of the unit in some cases, saving time and money.
The hinged access door grants easy access for general service and to the DSI control board.
Finally, the company included removable terminal blocks for both line voltage and thermostat wires. This convenience allows technicians to remove the plugs from the board, quickly wire the connections, and re-attach the plug without having to try and get a screwdriver to each terminal while standing on a ladder or in a lift.
On the performance side, the LF25’s foundation is the tubular heat exchanger, a standard feature of all Lennox unit heaters. The dimpled tubular design is meant to maximize efficiency and provide excellent heat transfer by completely exposing the heating surface to the air stream. Lennox added that the tubular construction minimizes air resistance to allow for even heating across all surfaces increasing reliability.
Part of the LF25 unit heater’s appeal is its ability to deliver comfort without delivering noise. The manufacturer emphasized that these are built to provide an environment that is both warm and peaceful. Lennox reported that the LF25 generates 25 percent less pure tones and projection than other options. Design improvements for chassis, mounting grill, and fan components further enhance the unit’s low-noise performance.
To ensure the reliability Roy mentioned, each unit is factory-wired and tested with complete cycles of startup and shutdown before being shipped. Once in place, the heater keeps routine cleaning effort minimal thanks to an easy-to-reach, in-shot cluster burner assembly.
This year’s Light Commercial Silver medal goes up on the roof, directly to Carrier’s Weather Series Packaged Rooftops with EcoBlue Technology™.
This single package design includes all the cooling, heating, and ventilation needs from one device for zone comfort control. Fresh air and free cooling is provided through the unit’s internal economizer design and can be integrated with Demand Control Ventilation logic and Fault Diagnostic and Diagnostic controls.
In an era where existing equipment and space constraints are a common issue, Carrier said it held the unit’s footprint to actual sizes from the late 1980s to ensure that replacement projects would not require special adapter curbs or even more extensive modifications.
Carrier describes the Vane Axial Indoor Fan System as an industry first to be used with an RTU, built to use 75 percent fewer moving parts and eliminate common pain points for customers and technicians. Techs can set indoor fan speed from the unit control box easily, no need for strobe light, remove panels, or make pulley or belt adjustments.
The SystemVu™ controller trades the need for traditional refrigerant gauges for working through the text display on a backlit menu to access refrigerant system pressures.
Lennox Commercial bookends the category this year, taking the Bronze with its VRB Heat Recovery Outdoor Units.
The three-pipe design for these units features a dedicated hot gas line and enables simultaneous heating and cooling. The single-module capacities are available up to 16 tons, while twin and triple modules expand up to 42 tons, achieving up to 32.8 Simultaneous Cooling & Heating Efficiency (SCHE).
Lennox cites the long pipe lengths and individual zone temperature controls in making these ideal for high-rise buildings, hotels, schools, and offices, although they can also serve settings like grocery and even indoor hydroponic grow facilities.
Just for contractors, the hinged doors allow quick, toolless access to internal components. Moreover, integral braces hold them open to allow installers and technicians to work safely and more easily. Its LCD console is detachable, with a 10-foot-long cable to let techs use it and close the doors for more accurate testing readings.
Speaking of hinges, a double-hinged electrical panel allows quick access to internal components. A final design detail for safety and convenience: the main control board sits on a hinged panel within the larger hinged control box.