Specifications

Manual 2100-533E
Page 6 of 12
ENERGY RECOVERY VENTILATOR
MAINTENANCE
GENERAL INFORMATION
The ability to clean exposed surfaces within air moving
systems is an important design consideration for the
maintenance of system performance and air quality.
The need for periodic cleaning will be a function of
operating schedule, climate, and contaminants in the
indoor air being exhausted and in the outdoor air being
supplied to the building. All components exposed to
the airstream, including energy recovery wheels, may
require cleaning in most applications.
Rotary counterow heat exchangers (heat wheels)
with laminar airow are “self-cleaning” with respect
to dry particles. Smaller particles pass through;
larger particles land on the surface and are blow clear
as the ow direction is reversed. For this reason
the primary need for cleaning is to remove lms of
oil based aerosols that have condensed on energy
transfer surfaces. Buildup of material over time may
eventually reduce airow. Most importantly, in the
case of desiccant coated (enthalpy) wheels, such lms
can close off micron sized pores at the surface of the
desiccant material, reducing the efciency with which
the desiccant can absorb and exude moisture.
FREQUENCY
In a reasonably clean indoor environment such as a
school, ofce building, or home, experience shows that
reductions of airow or loss of sensible (temperature)
effectiveness may not occur for ten or more years.
However, experience also shows that measurable
changes in latent energy (water vapor) transfer can
occur in shorter periods of time in commercial,
institutional and residential applications experiencing
moderate occupant smoking or with cooking facilities.
In applications experiencing unusually high levels
of occupant smoking, such as smoking lounges,
nightclubs, bars and restaurants, washing of energy
transfer surfaces, as frequently as every six months,
may be necessary to maintain latent transfer efciency.
Similar washing cycles may also be appropriate for
industrial applications involving the ventilation of high
levels of smoke or oil based aerosols such as those
found in welding or machining operations, for example.
In these applications, latent efciency losses of as much
as 40% or more may develop over a period of one to
three years.
NOTE: Sensible
performance only
is shown for winter
application.
TABLE 3
WINTER HEATING PERFORMANCE — (INDOOR DESIGN CONDITIONS 70°F DB)
LEGEND
VLT = Ventilation Load – Total HRS = Heat Recovery – Sensible VLS = Ventilation Load – Sensible
Ambient
O.D.
VENTILATION RATE
450 CFM
80% EFFICIENCY
375 CFM
81% EFFICIENCY
300 CFM
82% EFFICIENCY
DB/°F VLT HRS VLS VLT HRS VLS VLT HRS VLS
65 2430 1944 486 2025 1640 385 1620 1328 292
60 4860 3888 972 4050 3280 770 3240 2656 583
55 7290 5832 1458 6075 4920 1154 4860 3985 875
50 9720 7776 1944 8100 6561 1539 6480 5313 1166
45 12150 9720 2430 10125 8201 1924 8100 6642 1458
40 14580 11664 2916 12150 9841 2309 9720 7970 1750
35 17010 13608 3402 14175 11481 2693 11340 9298 2041
30 19440 15552 3888 16200 13122 3078 12960 10627 2333
25 21870 17496 4374 18225 14762 3463 14580 11955 2624
20 24300 19440 4860 20250 16402 3848 16200 13284 2916
15 26730 21384 5346 22275 18042 4232 17820 14612 3208
10 29160
23328 5832 24300 19683 4617 19440 15941 3499
5 31590 25272 6318 26325 21323 5002 21060 17269 3791
0 34020 27216 6804 28350 22964 5387 22680 18598 4082
-5 36450 29160 7290 30375 24604 5771 24300 19926 4374
-10 38880 31104 7776 32400 26244 6156 25920 21254 4666