SLR Series

SLR Series

Rooftop HVAC System featuring ComforTEK for Shuttle and School Bus Applications.

The all-new, ultra-low profile SLR Series represents a dramatic shift from designs of the past, bringing innovative design concepts that improve airflow with Thermo King’s ComforTEK to increase comfort and efficiency.



A unique through-roof design concept engineered to deliver what matters to our customers.

Improved Passenger Comfort  

  • Ultra-slim integrated design, the SLR gives passengers more headroom than conventional systems.
  • Two-way airflow means comfortable air for all passengers, with no hot or cold spots. 

More Even Weight Distribution  

  • Located at the center of the bus, the SLR's weight is evenly distributed across the bus chassis for optimized weight distribution.

Easy Maintenance

  • The patent-pending through-roof design of the SLR allows for easy service access, with 90% of all maintenance able to be performed from inside the bus.

Lightweight, Durable and Rustproof 

  • The SLR features a rustproof structural foam ABS cover, which weights less than fiberglass and is more durable.

Feature Benefit
Through-Roof Design

Easy access - 90% of service can be performed from inside bus

20-25% quicker installation

Safer work environment - no climbing on roof

Control panel located inside bus

Low-Profile Design

Sleek, modern look for any bus roof

Mechanical Fittings

Ease of maintenance

Modular Construction

Reduced installation time

Eliminates long runs of hoses in bus chassis

Moves condenser from the ground, less maintenance, longer life

40% less refrigerant charge

Multiple Configurations
from One Basic Design

Flexibility to configure a system for buses from 14’ to 32’

Flexibility to configure a system for any climate zone

Injected Structural
Foam Construction

Lightweight, rustproof and recyclable


Choose SLR for all small and medium bus applications from 16' to 35'

Bus Length Unit Capacity (IMACA BTU/hr) Compressor
16’-20’ SLR 65 60,000 TM16
21’-24 SLR 65 66,000 TM21
25’-28’ SLR75 75,000 TM21
29’-32’ SLR 75 84,000 TM31
33’-35’ 2xSLR65 132,000 2xTM21



Take control of your operating costs with these options available only from Thermo King.

IntelligAIRE® Microprocessor Controller

Precise temperature control with diagnostics, CAN communications, and optional driver’s display.

  • Diagnostics accessible through optional display or PC interface tool
  • Configurable programs 
  • Select set point digitally 
  • Temperature display 
  • Automatic temperature and mode control 
  • Alarm LEDs 

TM 16 and TM 31 Compressors

Added Flexibility to configure systems for specific applications


Supplemental heat for cold weather applications and dehumidification for cool humid climates


Why pay for more than you want. Thermo King provides standard features designed to meet your needs.

  • Simple Control System 
    • On/off switch and a three-speed fan switch. 
  • Environmentally Safe R-134a
    • Zero ozone depletion 
  • TM 21 Compressor
    • High capacity for a wide range of applications
  • Oversized Return Air Filter
    • Added protection for longer system life
  • Micro-Channel Condenser Technology
    • Low weight and higher efficiency
  • TK2000 EZ-Clip Hoses and Fitting
    • Reduce the potential for leaks

SLR Specifications

System Cooling Capacit (IMACA Rated Capacities) SLR 65 SLR 75
BTU/hr (w/TM-21 Compressor) 66,000 75,000
System Heating Capacity (Rated Capacities - 195 °F 50/50 glycol, 3.0 GPM, 60°F inlet air)
BTU/hr 42,0000 n/a
Evaporator Airflow (0 in. water column external static pressure)
High Speed 940 CFM 900 CFM
HFC R-134a HFC R-134a
Power Consumption @ 13.5 VDC
65 Amps 65 Amps
124 lbs (130 lbs with heat) 131 lbs
Compressor Weight With Clutch (approximate)

TM 16   18 lbs (8.2kg)
TM 21   19 lbs (8.6kg)
TM 31   36 lbs (16.3kg)

SLR series bus shuttle

Achieve optimum passenger comfort with our exclusive ComforTEK system

  • Better Air Distribution for More Comfortable Passengers
  • Multi-Directional Airflow Means No Hot or Cold Spots
  • Balanced Performance for Lower Energy Consumption
  • Lower Profile Design for Increased Passenger Headroom
  • 40% Less Refrigerant Required for Cost and Environmental Savings

Photo showing a School Bus with a solar panel

ThermoLite® Solar Panels for School Bus Applications for Bus Applications

The perfect solution for preventing costly battery issues on smaller vehicles and school buses.

Contact Us to Learn More about Bus HVAC Systems

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