Architectural heat and moisture exchange

Abstract

An architectural heat and moisture exchanger. The exchanger defines an interior channel which is divided into a plurality of sub-channels by a membrane configured to allow passage of water vapor and to prevent substantial passage of air. In some embodiments, the exchanger includes an opaque housing configured to form a portion of a building enclosure, such as an exterior wall, an interior wall, a roof, a floor, or a foundation.

Description

CROSS-REFERENCES[0001]This application claims priority from U.S. Provisional Patent Application Ser. No. 61 / 365,173, filed Jul. 16, 2010 which is incorporated herein by reference. This application also incorporates by reference in its entirety for all purposes the following: U.S. Pat. No. 6,178,966, issued Jan. 30, 2001 and U.S. Patent Publication No. 2007 / 0151447 to Merkel, published Jul. 5, 2007.INTRODUCTION[0002]In centrally heated or cooled buildings, fresh air or “makeup air” is typically added continuously to the total volume of circulated air, resulting in some previously heated or cooled air being exhausted from the building space. This can result in an undesirable loss of energy and humidity from the building. Heat exchangers are commonly used in the exhaust air and makeup airflow paths of these systems to recover some of the energy from the exhaust air and to induce warmer makeup air during heating processes and cooler makeup air during cooling processes.[0003]Materials us...

AI Technical Summary

Benefits of technology

[0007]U.S. Pat. No. 6,178,966 to Breshears addressed the shortcomings described above by describing an improved apparatus for enabling heat and moisture exchange between makeup and exhaust air streams in the heating and air conditioning system of a structure. The apparatus included a rigid frame for holding a pair of light transmitting panes, the frame and panes collectively defining an interior cavity within the apparatus. The apparatus could be integrated into the exterior walls of a building. The light transmitting properties of the panes allow incident solar radiation to permeate the panels, creating a more natural ambient environment in the interior of the structure adjacent with the panel, as well as raising the temperature of the air stream and the water vapor permeable barrier to further enhance the exchange of moisture through the barrier.

Problems solved by technology

In centrally heated or cooled buildings, fresh air or “makeup air” is typically added continuously to the total volume of circulated air, resulting in some previously heated or cooled air being exhausted from the building space.

This can result in an undesirable loss of energy and humidity from the building.

Good heat exchange is generally possible with these materials, but significant moisture exchange cannot easily be performed.

However, water absorbed by the paper from condensation, rain, or moisture present in the air can lead to corrosion, deformation, and mildew growth, and, hence, deterioration of the paper exchange film.

The nature of moisture exchange requires a very large surface area in contact with the gas stream, and, consequently, so-called total heat exchangers are often very large in size when compared to heat-only exchangers.

A disadvantage of such porous composite film is that it also permits the exchange of substantial amounts of air between the gas streams, as well as particles, cigarette smoke, cooking odors, harmful fumes, and the like.

With respect to building indoor air quality, this is undesirable.

In order to prevent this contamination of make-up air, the pore volume of a porous film is preferably no more than about 15%, which is difficult and expensive to achieve uniformly.

Furthermore, a porous film made to a thickness of 5 to 40 micrometers in order to improve heat exchange efficiency tears easily and is difficult to handle.

Despite overcoming some of the shortcomings of preexisting systems, the prior art Breshears apparatus was limited in some ways.

For example, the disclosed apparatus was limited to transparent structures configured to be integrated into the exterior of a building.

Furthermore, the polymeric membranes described by Breshears were limited to certain particular membrane materials.

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