3. HEAT PIPES FOR HEAT RECOVERY
Building regulations stipulate a minimum air change rate for occupied zones. Whilst it is obviously beneficial to rid the atmosphere of airborne contaminants, it is less attractive to rid the zone of heat, which must be replaced at considerable cost.
Heat pipe heat recovery modules are a cost effective method of maintaining indoor air quality while reducing heating or cooling loads. Thermal energy is recovered from exhaust air and transferred through the heat pipe to the supply (outside) air with an effectiveness reaching as high as 75”%. Other benefits include minimum installation and start up costs when compared to alternative methods currently in use.
Such a system should be considered whenever air is being mechanically supplied at the same time as air at a different temperature is being exhausted.
Besides IAQ concern in both commercial and residential structures, heat recovery is also widely used in industrial process applications. Manufacturers are always looking for ways to optimise their production process, but often overlook heat recovery as a bottom line benefit. In industrial settings, heat pipes allow process waste heat to be recovered with no cross contamination.
Additionally, heat pipes can be treated to withstand just about any corrosive environment while retaining virtually 100% of their effectiveness.
Typical applications of the system have included HVAC, swimming pools, drying processes, paint spray booths, laundries, kitchens etc.
BASIC COMPARISON INFORMATION
Many types of heat exchangers are available for heat recovery applications. However, each type of heat exchanger has certain advantages and drawbacks: RUN-AROUND COIL are relatively inexpensive, but require a pump pack and expansion tank to operate. Run-around loops used in cold climates must be charged with anti-freeze to prevent frost damage. They are however, the best solution for ‘separate’ air streams. PLATE-TO-PLATE heat exchangers are quite effective, but are bulky, expensive and very difficult to clean. They can trap condensate resulting in the growth of moulds. HEAT RECOVERY WHEELS are maintenance intensive and prone to cross-contamination and do not effectively drain condensation.
Only heat pipes offer all the benefits combined: no moving parts, high effectiveness, low air-pressure drop, easy drainage of condensation, no direct energy requirement, are totally passive and have zero cross-combination. They are also proven to be long lasting and virtually maintenance free!
4. LOCAL JOB REFERENCE Project List
Kwai Chung Public Mortuary
Peking Road No. 1
Penny's Bay - Fire Station with Ambulance Depot and Police Post
QE Hospital - Pharmacy Department
Shatin Sewage Treatment Works
Tai Po Complex
The Hong Kong University of Socience and Technology - MMF Phase Rm.1043
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