Page 56 - Green Builder March-April 2020 Issue

IAQ: Breathe Easier

Products, Research and Advice for Improving Indoor Air Quality

Field Test: Ventilating an

ADU for Optimal Air Quality

By combining an “always on” ERV and quiet bath fan, this installation achieved
above-and-beyond air quality.

A quality assignment.
BY MATT POWER The Panasonic FV-VE401 Energy
NE OF THE CHALLENGES WITH SMALL “mother- Recovery Ventilator had a simple
in-law” apartments and accessory dwelling task in this ADU: improve air
quality, eliminate odors
units (ADUs) is that they’re often built without and reduce buildup of
adequate ventilation, or they have unbalanced volatile organic
systems that create drafts or fail to clear the air, compounds (VOCs).
or worse, haul other pollutants back into the COURTESY OF PANASONIC
O building.
For example, most range hoods operate at 300 cfm or higher only.
When you switch on a range hood in a building with the footprint
of a garage, you can quickly depressurize the space, pulling air in
indiscriminately from unwanted sources (such as the garage, in the
case of an apartment over parking).
While upgrading the ceilings in a small accessory structure in
Florida, we saw an opportunity to test one of the new ceiling insert
Energy Recovery Ventilators (model FV-VE401) from Panasonic in
conjunction with an exhaust-only bath fan (model FV 0511VKSL2),
as a whole-house air quality solution. With a total square footage
under 400, it would also meet the de nitions of a tiny house, by Quick opportunity.
most standards, and the same size approximation would apply to a Panasonic’s exhaust-only bath fan,
park model RV. the FV 0511VKSL2, was an easy
We had three goals in mind with the test: install and became an integral
Meet the minimal ventilation standards (ASHRAE 62.2) at part of the tiny home’s
low energy cost. low-cost ventilation
Remove unpleasant odors from the house on demand. improvement plan.
COURTESY OF PANASONIC
Reduce buildup of volatile organic compounds (VOCs) and
odors from building materials and behavior.

Installing the Units
Panasonic has spent years simplifying installation of its equipment
and making them about as close to turnkey as you can get.
The bath fan took only about 15 minutes to set and install. The
ERV took a little longer, because it’s a larger, heavier unit—and the
rafter distance was not 16 OC. To secure it, we had to build out some
2-by-4 framework.
One of the more helpful details the company includes as part of
the ERV carriage is a built-in measuring gauge that allows you to set
the depth of the unit, depending on your ceiling type. We set ours

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