Solar UV transmissive device for sterilizing and/or heating air

Abstract

An outdoor air conduit or plenum is provided with a UV transmissive surface for allowing the air circulated through the conduit to be exposed to the UV rays of the natural sunlight, thereby providing for the sterilization of the air using free energy. The air sterilization system can be integrated to a building ventilation system or combined with a solar heat collector.

Description

TECHNICAL FIELD[0001]The present application generally relates to a device and a method suited for sterilizing and / or heating air by means of free energy, such as solar energy. For instance, the device can be used for heating and sterilizing the air of a building.BACKGROUND ARTThe Sterilizing Effect of UV Rays[0002]Ultraviolet rays (UV rays) are known to have a purifying effect on water as well as on air.[0003]In closed systems, the re-circulated building air accumulates pathogeneous organisms that may generate diseases. Among the various types of UV rays, the UV-C rays are known to inhibit the growth and the reproducing of germs, viruses, allergies and bacteria's that circulate in warm or cold air ducts systems.[0004]Over the years various UV rays generators have been developed in an attempt to process and purify air in a given environment. While it is known that solar radiation contains UV rays that have a sterilizing effect, there is, according to applicant's knowledge, no device...

AI Technical Summary

Benefits of technology

[0012]In accordance with another general aspect, there is provided a device for heating and sterilizing air comprising a perforated UV transmissive surface allowing at least part of the solar radiations, including UV rays, to pass therethrough, a solar radiation absorption surface located behind said perforated UV transmissive surface for absorbing the solar radiations, and a plenum defined between said perforated UV transmissive surface and said radiation absorption surface, the air flowing in the plenum absorbing heat from the radiation absorption surface while being exposed to UV rays, thereby providing for the combined heating and sterilization of the air in the plenum by solar energy. The perforations in the UV transmissive surface provides for a reduced temperature delta through the UV transmissive surface, thereby ensuring a better heat transfer efficiency.

[0030]According to a still further general aspect, the system for sterilizing the air of a building can be used for disinfecting buildings such as hospital, school, grocery stores, office towers, medical practices, waiting rooms etc. This can contribute to substantially reduce the amount of disinfecting compounds such as biocides, fungicides, bactericides and antibiotics injected in the air circulating in such buildings.

Problems solved by technology

While it is known that solar radiation contains UV rays that have a sterilizing effect, there is, according to applicant's knowledge, no device currently on the market which makes active use of the benefits or solar energy to sterilize the air.

When the glazing becomes very warm, the collectors become less efficient.

However, for unitary flow rates below 5 cfm per square foot, the amount of cool air leaching the perforated plate is insufficient to prevent the collector plate from heating up, thereby negatively affecting the overall thermal efficiency of the system.

The air circulating under or behind the absorbers never “sees” sunlight and therefore the sterilizing properties of the sun are not being put to advantage.

Furthermore, traditional glass used as top glazing is not transparent to the sun's UV rays, therefore the heated air never gets the sterilizing benefits of the sun's UV rays.

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