Launch of the Spray Painting Waste Heat Recovery System

Energy consumption in spray painting workshops has long been a heavy burden for manufacturers. Spray booths require large volumes of fresh air to maintain constant temperature and humidity, while curing ovens are notorious “power or gas guzzlers”. Statistics show that the painting process accounts for 15%–25% of a factory’s total energy use, most of which is directly discharged as waste heat into the atmosphere, causing massive energy waste and carbon emissions. Dongguan Mansheng Automation Equipment Co., Ltd. has officially launched its Spray Painting Waste Heat Recovery System, which recovers and reuses waste heat in cascade from spray booth exhaust, curing oven residual heat, and air compressors. The system reduces the overall energy consumption of spray booths by more than 35%, with a typical payback period of 1–2 years. The technology has been applied to coating lines of leading enterprises such as BYD and Midea, with each system reducing approximately 80 tons of CO₂ emissions per year in actual operation.

The energy flow of a standard automatic painting line (spray booth + curing oven) is as follows:

• To ensure safety and coating quality, spray booths draw in massive fresh air (20–30 air changes per hour) and discharge treated exhaust containing paint mist and solvents. Heating or cooling fresh air to maintain 20–25°C accounts for over 60% of the booth’s total energy use.
• Curing ovens operate at 60–180°C for coating solidification, consuming huge amounts of energy via hot air or infrared heating.
• Air compressors convert about 80% of electricity into heat during operation, which is wasted in compressor rooms.

“Many companies only focus on buying more energy-saving painting equipment, but ignore the huge amount of heat already being wasted,” said an energy engineer at Mansheng Automation. “Waste heat recovery is one of the most cost-effective energy-saving methods.”

The system is not a single device but a combined solution designed for different heat sources and temperature zones. Customers can choose configurations based on workshop conditions and budget.

The system is centrally controlled by a central energy efficiency controller, which monitors real time temperature, flow, and equipment status and automatically allocates heat:

• Prioritize oven waste heat for fresh air heating or workpiece drying
• Supplement with compressor waste heat when oven heat is insufficient
• Direct excess heat to workshop heating or hot water
• Disable partial recovery loops in summer to avoid overheating

“We integrate waste heat recovery into the overall control logic of the painting line, not as an independent add on,” said a Mansheng electrical engineer. “For example, during color change and cleaning, the system automatically adjusts recovery ratios to maximize energy savings.”

A home appliance coating factory in Foshan, Guangdong operates two automatic painting lines (Mansheng 6th generation equipment), with annual electricity use of ~2.1 million kWh and natural gas use of ~250,000 m³. After installing a full three stage waste heat recovery system in 2024, one year results:

Payback period: Total investment ~¥580,000, recovered in 11 months. Annual CO₂ reduction ~142 tons, plus a government energy saving subsidy of ¥120,000.

The system delivers maximum benefits for:

• Northern regions (long heating season, high heating load)
• Curing ovens above 120°C (high temperature baking, powder curing)
• Large air compressors (≥50kW)
• 24/7 continuous production
• Facilities with hot water demand (dormitories, cleaning lines)

For small, intermittent workshops in southern China, the payback period may be longer. Mansheng provides free on site assessments.

With China’s “Dual Carbon” strategy, energy intake enterprises face carbon quota management. Lower energy use directly translates to surplus carbon quotas that can be traded for profit or avoid penalties. Lower exhaust temperature also improves the stability of downstream exhaust treatment systems (zeolite rotor + RTO) and reduces their preheating energy use. Mansheng helps clients apply for energy saving renovation subsidies (10%–20% of equipment investment) and Green Factory certifications.

To prevent clogging by paint mist, Mansheng uses targeted design:

• Installed after the exhaust filtration stage to remove most paint mist
• Detachable heat exchanger for easy cleaning every 3–6 months
• Special fin spacing (≥6mm) and 15° self cleaning tilt to reduce particle buildup
• Pulse back blowing before exchangers for regular dust removal

“Conventional exchangers lose 50% efficiency in three months. Our design keeps performance degradation below 10% in three years,” said a Mansheng product manager.

*Note: Values vary by energy prices and operating hours.

To lower upfront costs, Mansheng offers three options:

1. Direct Purchase: One time purchase, 2 year warranty.
2. Financial Leasing: 30% down payment, 36 installments with partial interest subsidy.
3. Energy Performance Contracting (EPC): Mansheng funds the system; shares 40% of energy savings for 3–5 years, then transfers ownership free of charge.

Mansheng is developing an integrated solution: Waste Heat Recovery + Solar PV + Energy Storage. Rooftop PV powers equipment, energy storage cuts peak loads, and waste heat recovery reduces thermal energy use. Together, they lower total energy costs by over 50%, approaching zero carbon. The first demo project at Mansheng’s Dongguan No.2 plant will generate 900,000 kWh per year, reducing overall energy use by 42% vs. industry average.

Mansheng provides free on site energy audits nationwide. Engineers measure energy use, identify waste points, and deliver a detailed retrofit and ROI report – at no cost to the customer. Over 80 companies have already booked audits.