Vancouver, Canada

dPoint Technologies

www.dpoint.ca
Vancouver, Canada
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Water vapor transport membranes for ERV and other water vapor transport applications are provided. The membranes include a substrate and an air impermeable selective layer coated on the substrate, the selective layer including a cellulose derivative and a sulfonated polyaryletherketone. In some embodiments the sulfonated polyaryletherketone is in a cation form and/or the selective layer includes s PEEK and CA in an s PEEK:CA (wt.:wt.) ratio in the range of about 7:3 to 2:3. Methods for making such membranes are provided. The methods include applying a coating solution/dispersion to a substrate and allowing the coating solution/dispersion to dry to form an air impermeable selective layer on the substrate, the coating solution/dispersion including a cellulose derivative and a sulfonated polyarylether ketone. In some embodiments the sulfonated polyaryletherketone is in a cation form and/or the coating solution/dispersion includes s PEEK and CA in an sPEEK:CA (wt.:wt.) ratio in the range of about 7:3 to 2:3.


Water vapor transport membranes for ERV and other water vapor transport applications are provided. The membranes include a substrate and an air impermeable selective layer coated on the substrate, the selective layer including a cellulose derivative and a sulfonated polyaryletherketone. In some embodiments the sulfonated polyaryletherketone is in a cation form and/or the selective layer includes s PEEK and CA in an s PEEK:CA (wt.:wt.) ratio in the range of about 7:3 to 2:3. Methods for making such membranes are provided. The methods include applying a coating solution/dispersion to a substrate and allowing the coating solution/dispersion to dry to form an air impermeable selective layer on the substrate, the coating solution/dispersion including a cellulose derivative and a sulfonated polyarylether ketone. In some embodiments the sulfonated polyaryletherketone is in a cation form and/or the coating solution/dispersion includes s PEEK and CA in an sPEEK:CA (wt.:wt.) ratio in the range of about 7:3 to 2:3.


Nasr M.R.,dPoint Technologies | Simonson C.J.,University of Saskatchewan
ASHRAE Transactions | Year: 2017

Frosting in air-to-air energy exchangers is a common problem when the outdoor air temperature is very low. Membrane-based air-to-air energy exchangers that are capable of moisture transfer as well as sensible heat transfer may assist in overcoming frosting. To understand the effect of water vapor transfer on frosting, laboratory experiments were conducted to investigate the frosting conditions for two geometrically identical air-to-air cross-flow plate exchangers. One exchanger was made with a water vapor permeable membrane (energy exchanger), while the other exchanger was made with an impermeable polymer film with similar thickness (heat exchanger). Tests for heat and energy exchangers were conducted in several operating conditions to detect the conditions that resulted in frosting in the exchangers. The laboratory test conditions for the exchangers were 0°C (32°F) to -32°C (-26°F) for the supply inlet (simulated outdoor air) temperature and 5% to 55% exhaust inlet (simulated indoor air) relative humidity, while exhaust inlet temperature was ≈22°C(72°F). Flow rates in the supply and exhaust air streams were maintained at 20.8 LIS (≈40 cfm) to provide a balanced mass flow rate of dry air between the two air streams. Experimental results confirmed that the energy exchanger was more frost resistant than the heat exchanger. For example, when the indoor relative humidity was 30%, frost formed in the energy exchanger for outdoor temperatures of -10°C (14°F) or lower, whereas the heat exchanger frosted at -5°C (23°F). Additionally, the lower the indoor relative humidity, the lower the frosting limit temperature. Both heat and energy exchangers experienced frosting for almost all indoor relative humidities tested when the supply temperature was less than -25°C (- 13°F). Determining the operating conditions in which frostfirst begins to form (frosting limit) will help designers and engineers to select a suitable exchanger and apply properfrost protection techniques. © 2017 ASHRAE.


Patent
dPoint Technologies | Date: 2012-12-19

A heat and humidity exchanger has example application in exchanging heat and water vapour between fresh air entering a building and air being vented from the building. The heat and humidity exchanger has a self-supporting core formed from layered sheets (710, 720) of a moisture-permeable material. Plenums (750) are arranged to direct fluid streams into and out of the core. The plenums (750) may be on opposing sides of the core to permit counterflow exchange of heat and water vapour. The plenums (750) are attached to the core along opposite edges of the sheets (710, 720).


A membrane cartridge is manufactured by repeatedly folding and joining two strips of membrane to form a cross-pleated cartridge with a stack of openings or fluid passageways configured in an alternating cross-flow arrangement. The cartridge can be modified for other flow configurations including co-flow and counter-flow arrangements. Methods for manufacturing such cross-pleated membrane cartridges, as well as apparatus used in the manufacturing process are described. Cross-pleated membrane cartridges comprising water-permeable membranes can be used in a variety of applications, including in heat and water vapor exchangers. In particular they can be incorporated into energy recovery ventilators (ERVs) for exchanging heat and water vapor between air streams being directed into and out of buildings.


Patent
dPoint Technologies | Date: 2010-05-17

Coated membranes comprise a porous desiccant-loaded polymer substrate that is coated on one surface with a thin layer of water permeable polymer. Such membranes are particularly suitable for use in enthalpy exchangers and other applications involving exchange of moisture and optionally heat between gas streams with little or no mixing of the gas streams through the membrane. Such membranes have favorable heat and humidity transfer properties, have suitable mechanical properties, are resistant to the crossover of gases when the membranes are either wet or dry, and are generally low cost.


A water vapour transport membrane comprises a nanofibrous layer disposed on a macroporous support layer, the nanofibrous layer coated with a water permeable polymer. A method for making a water vapour transport membrane comprises forming a nanofibrous layer on a macroporous support layer and applying a water permeable polymer to the nanofibrous layer. The water permeable polymer can be applied for so that the nanofibrous layer is substantially or partially filled with the water permeable polymer, or so that the coating forms a substantially continuous layer on one surface of the nanofibrous layer. In some embodiments of the method, the nanofibrous layer is formed by electro-spinning at least one polymer on at least one side of the porous support layer. In some embodiments, the support layer is formable and the method further comprises forming a three-dimensional structure from the water vapour transport membrane, for example, by compression molding, pleating or corrugating.


Patent
dPoint Technologies | Date: 2016-06-16

A heat and humidity exchanger has example application in exchanging heat and water vapor between fresh air entering a building and air being vented from the building. The heat and humidity exchanger has a self-supporting core formed from layered sheets of a moisture-permeable material. Plenums are arranged to direct fluid streams into and out of the core. The plenums may be on opposing sides of the core to permit counterflow exchange of heat and water vapor.


A water vapour transport membrane comprises a nanofibrous layer disposed on a macroporous support layer, the nanofibrous layer coated with a water permeable polymer. A method for making a water vapour transport membrane comprises forming a nanofibrous layer on a macroporous support layer and applying a water permeable polymer to the nanofibrous layer. The water permeable polymer can be applied for so that the nanofibrous layer is substantially or partially filled with the water permeable polymer, or so that the coating forms a substantially continuous layer on one surface of the nanofibrous layer. In some embodiments of the method, the nanofibrous layer is formed by electro-spinning at least one polymer on at least one side of the porous support layer. In some embodiments, the support layer is formable and the method further comprises forming a three-dimensional structure from the water vapour transport membrane, for example, by compression molding, pleating or corrugating.


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