Bus Air Conditioning Refrigerants Comparison – A Complete Guide for Bus OEMs & Fleet Operators

Global carbon emission regulations are getting stricter year by year, and extreme high-temperature weather occurs frequently around the world. When bus manufacturers and fleet operators purchase bus air conditioning systems, the choice of refrigerant directly affects environmental compliance, vehicle operating costs and passenger riding experience.

With 39 years of professional R&D and manufacturing experience in the bus air conditioning industry, TCHAIN Taichang sorts out all mainstream refrigerants matched with our full range of electric and diesel bus air conditioners. This article covers refrigerant working principles, environmental evaluation indicators, product matching models, advantages and disadvantages, as well as future industry trends, to provide professional reference for global bus buyers.

Working Principle of Bus Air Conditioning Refrigerant Cycle

All rooftop, built-in and new energy bus air conditioners produced by TCHAIN follow the vapor compression refrigeration cycle, with four continuous core steps:

1. Compression: The compressor compresses low-pressure gaseous refrigerant into high-temperature and high-pressure gas.

Condensation: High-pressure gaseous refrigerant flows through the condenser, dissipates heat out of the vehicle and liquefies into liquid refrigerant.

Expansion: Liquid refrigerant passes through the expansion valve, the pressure drops rapidly and turns into low-temperature atomized mixture.

Evaporation: The atomized refrigerant absorbs heat inside the evaporator and vaporizes, taking away heat in the passenger compartment to realize cooling.

Two Core Environmental Indicators: ODP & GWP

Before comparing various refrigerants, we need to understand two key evaluation standards recognized globally:

1. ODP (Ozone Depletion Potential): It represents the damage degree of refrigerant to the ozone layer. All mainstream modern bus air conditioning refrigerants have ODP=0, which is the basic access standard for the market.

2. GWP (Global Warming Potential): It measures the greenhouse effect of refrigerant within 100 years. The lower the GWP value, the more environmentally friendly it is. EU F-Gas regulations and the Kigali Amendment are gradually restricting high-GWP refrigerants.

Mainstream Refrigerants Matching TCHAIN Bus Air Conditioners

1. R134a – Special Refrigerant for Traditional Diesel Bus Air Conditioners

Basic performance: ODP=0, GWP over 1000, non-toxic and non-flammable.

Applicable TCHAIN models: TCH05B, TCH07GZ, TCH07IZ, TCH08A, TCH09MB, TCH11SA, TCH12TC, TCH13V series diesel air conditioners, as well as TCN series built-in air conditioners for fuel buses, covering 5-14m coaches, school buses and special vehicles.

Advantages: Mature supporting technology, low procurement and after-sales maintenance cost, complete global service network.

Disadvantages: High GWP value, many European and American regions have restricted its use on newly launched buses.

2. R407C – Early Refrigerant for Small New Energy Buses

Basic performance: Mixed refrigerant, ODP=0, high GWP, large cooling capacity.

Applicable TCHAIN models: TCD07A new energy air conditioner for 6-7m small electric buses.

Advantages: High cooling efficiency, low transformation cost for old equipment.

Disadvantages: Cannot meet the latest low-carbon environmental protection standards, gradually limited by regional policies.

3. R410A – Standard Matching Refrigerant for TCHAIN Full Series New Energy Air Conditioners

Basic performance: ODP=0, medium GWP, excellent heat pump cooling and heating comprehensive performance, adapted to DC420~720V high-voltage vehicle power supply.

Applicable TCHAIN models: TCD07D, TCD08D, TD40A, TCD12D all new energy air conditioner products, suitable for 6-12m pure electric buses.

Advantages: Stable operation under high voltage, supporting single cold, PTC heating, heat pump and various combined configurations, adapting to both southern high temperature and northern cold weather.

Disadvantages: Higher operating pressure than R134a, requiring professional installation and maintenance personnel.

Refrigerant Parameter & Application Comparison Table

Important Safety Reminders for Refrigerant Use

1. Different types of refrigerants are strictly prohibited from mixing. Mixing will cause compressor stuck, pipeline blockage, and even system safety accidents, resulting in permanent damage to the air conditioner.

2. All operations such as refrigerant recovery, replacement and filling must be completed by certified professional maintenance technicians with special tools.

3. All parameters, refrigerant types and filling amounts of TCHAIN air conditioners can be adjusted according to customer regions and vehicle requirements, and the final specifications shall be subject to the confirmation signed by both parties.

Why Choose TCHAIN Refrigerant Matching Solution

Founded in 1987, TCHAIN Taichang is a designated supporting supplier of well-known bus brands such as Yutong, King Long, CRRC, BYD and Geely. We own the Provincial Engineering Technology Research Center for new energy bus air conditioning, with independent R&D capability covering full-category products:

1. New energy bus air conditioner: TCD series for 6-12m pure electric vehicles

2. Traditional diesel bus air conditioner: TCH series for 5-14m fuel buses and school buses

3. Built-in bus air conditioner: TCN series for medium buses and double-decker buses

4. Complete set of air conditioning spare parts: compressors, heat exchangers, electronic control components, wiring harnesses, rubber and plastic accessories, etc.

We provide one-stop refrigerant matching scheme according to customers' sales area, vehicle length and power type, supporting OEM and ODM customization, and global after-sales technical support.

If you need targeted refrigerant matching solutions for your bus project, please contact TCHAIN professional sales team via sdtaichang@126.com.