Qingdao Kaineng Environmental Protection Technology Co., Ltd (Stock Code: 838388) is one of the largest boiler manufacturers in the China, it is a national leading high-tech enterprise, formally listed on stock market on August 5th, 2016, referred to as Kaineng Tech. The company mainly manufactures waste heat boiler, oil and gas fired boiler, economizer, pin tube, H-fin tube, spiral fin tubes, marine boiler and different kinds of pressure vessels and so on.

ZB GREAT IMP&EXP Co., Ltd, was established in July 2016, located at ZiboCity, Shandong Province Which is a famous heavy industry city and have along history.

BLJ is located in Dongsheng Huigu Park, Keqiao District, Shaoxing City, Zhejiang Province. The company is a science and technology-based environmental protection enterprise that integrates the research and development, design, production and sales of polymer membrane materials and washable total heat exchange core materials.

Zhengzhou Linker Medical Equipment Co., Ltd. is located in the center of beautiful city------Zhengzhou that is historical and cultural. Near the Chinese Mother River-----Yellow River, convenient traffic and information created more condition for developing of company.

Beijing HOLTOP Air Conditioning Co., Ltd. Has been specialized in air-to-air heat recovery and ventilation industry for more than 15 years. We have become one of the most biggest and famous one among China native similar enterprises. Headquarter based in Zhong Guancun North area of SCIENCE PARK, Beijing. The construction area covers 30, 000 m2, including plant area 20, 000 m2 and office building area 10, 000 m2. Yearly production capability reaches 100, 000 heat recovery equipments. HOLTOP independent developed high efficiency heat wheel, air to air plate heat exchanger, heat recovery AHU, HRV, ERV, fan coil etc. Products are trusted by native and overseas customers because of advanced technology, good quality and service. Among these products, HRV/ERV and rotary/plate heat exchanger have been maintaining market share first for many years.

TechFree supplies OEM/ODM with interest parties including AHU(Air Handling Unit), Modular AHU, Heat Exchangers and Ventilation Equipment, we also produce "TechFree" series Precision A/C and IAQ HVAV units.