About the PuriFresh® Energy Recovery Ventilator
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Product Specifications: |
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Ventilation Rate |
70 CFM (Cubic Feet per Minute) (max.) 50 CFM (min.) |
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Heat Recovery (sensible) |
85% at 70 CFM |
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Moisture Recovery (latent) |
60% at 70 CFM |
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Size and Weight |
18” x 11 ¾ ” x 9 ”, 23.5 pounds. |
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Energy Transfer Sections |
Silica gel powder, permanently bonded to plastic film. |
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Power |
45 Watts (max.) |
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Sound level at 70 CFM |
61 dB at 1 meter (Background
music is 60 dB) |
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Sound level at 50 CFM |
56 dB at 1 meter |
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Maximum Area Ventilated |
1500 square feet. (Assuming an
8 foot ceiling height) |
How It Works
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Each unit has
two blowers. One exhausts stale air from the room to the outside and the
other draws fresh air into the room from outside. Each unit also has four
"Energy
Transfer Sections" composed of closely spaced sheets of plastic
film, coated with desiccant. These are located directly under the exterior
cover. The stale air is forced through a "rotating air switch",
then through two Energy Transfer Sections before leaving the unit to the
outside. The position of the air switch determines which two Energy Transfer
Sections have stale air flow. The fresh air is drawn in through the remaining
two Energy Transfer Sections, then through the rotating air switch before
going through the blower and entering the room. |
Viewing any one
of the four Energy Transfer Sections in time, stale air flows out, followed
by fresh air in, and so on, as the rotating air switch turns. This
"breathing" action, caused by the rotating air switch, causes the
Energy Transfer Section to act as a heat and moisture or energy exchanger. In
winter, the warm moist stale air deposits heat and moisture on the Energy
Transfer Section. When the flow reverses and cold dry fresh air passes
through it, the heat and moisture is transferred to the fresh air. In summer,
the same principle works to keep heat and moisture out of the room. The desiccant greatly improves performance
in summer, removing humidity from the fresh air. |
The image below shows a PuriFresh® ERV in
our display window, viewed from outside the window. Streamers are attached to the four louvered outlets, to allow
visualization of the flow patterns during operation. Two additional streamers are attached to wooden dowels below the ERV
to help visualize the flow away from the ERV.
Click here on the image above to see a movie of the flows during operation. Note the streamers on the wooden dowels showing flow away from the unit. This shows that the stale air flows away from the ERV rather than being drawn back into the openings receiving fresh air. Click on our FAQs link to see how the Bernoulli principle keeps essentially all of the stale air from contaminating the fresh air.