STC-EHRV is a rotary wheel as the media for sensible and latent heat transfer between outdoor air and exhaust air. The wheel can be driven to rotate across the two air streams alternatively by a motor driven package housed within the casing of the unit. The media can be excellent at absorbing heat and control of humidity, at the same time can be efficient at exchanging air. The rotational speed of the wheel is around 19-29rpm. Noise level of the rotary wheel is below 30dBA.


Air Exchange

Two-way air exchanges constantly bring fresh air inside and take the exhaust air outside. Through the Polyester P.E. Fiber the indoor air has been refreshed with two independent pipes, one for fresh air intake and the other for expelling the exhaust air.


Air Flow Direction

  • Point 1 & 2 are fresh air intake
  • Point 3 & 4 are exhaust air out


Improve air quality by preventing the pollutants from floating in the air. Pollutants come in many different types, i.e. Carbon Dioxide, TVOC, HCHO, Radon, Benzene, and second hand smoke, etc.


Indoor Air Pollutants
During the process of air exchange using the EHRV, all the pollutants can be diluted by fresh air, as a result cleaner and fresher environment is achieved and improve IAQ to excellent class.


Rotary Heat Exchange

When carrying out the air exchange procedure, the temperature of the fresh air drawn inside will be approximate, at the same temperature as the existing room temperature. Therefore during the summer fresh air can be drawn in without raising room temperature and vice versa the cold air can be prevented to enter during fresh air exchange in the winter, therefore warmer air is kept inside.


Cycle Operation

  • Upper channel is exhaust air out
  • Lower channel is fresh air intake


Heat Transfer Material
  • Heat Recovery Rate:

   Sensible Heat 86-93% Latent Heat 72-80% Enthalpy 75-80%

  • Washable, Mildew Proof, Mildew Proof
  • Filtrate 80-95% particle >=PM10
  • Reusable for fifteen years
  • Fire certificate issued by FSD
  • Comply with A/C G.S. part of D5.1.3 in 2007 Edition (GSAC01)


The heat transfer media of STC-EHRV is named Polyester P.E. Fiber, which is formed from 25-150 micrometer diameter of specially formulated and highly penetrating polyester. Polyester P.E. Fiber has the highest heat recovery rate and is the most durable compared to other alternatives like ERV with aluminum foil, HRV with paper plate type, Thermo Wheel and Heat pipe are according to the self-experience of The University of Hong Kong. Polyester P.E. Fiber can be functioned efficiently with fabulous performance of more than 15 years while retaining its energy saving rate, and removable, washable and cleaned with low-pressure stream, water or light detergent without degrading the recovery effectiveness, and shall not be support the growth of bacteria.