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HR150B, HR200B PERFECT WINDOW™ FRESH AIR VENTILATION SYSTEMS
Airflow Balancing
Volume-balanced airflow in the ventilator is required. Volume of
outside air brought in must equal the volume of air the unit
exhausts. If airflow is not correctly balanced:
• unit does not operate at its maximum efficiency.
• negative or positive air pressure can occur in the house.
• unit will not defrost properly.
• warranty can be voided.
Excessive positive pressure can drive moist indoor air into
building external walls where it can condense (in cold weather)
and degrade structural components. Moist indoor air can also
cause keyholes to freeze.
Excessive negative pressure can have several undesirable
side effects; in some geographic locations, soil gases such as
methane and radon can be drawn into the home through
basement/ground contact areas. Excessive negative pressure
can also cause back drafting of vented combustion equipment
when adequate combustion air supply is not provided.
Balancing Procedure
Six-inch (150 mm) diameter flow collars connected to inclined
or digital manometer, or magnehelic, with range of 0 to.25 in.
(0 to 62.5 Pa) of water are recommended for accurate airflow
measurements. To avoid airflow turbulence and incorrect
readings, flow stations should be located at a distant point of at
least five duct diameters; for example, 6 in. (150 mm) duct
requires five diameters x 6 in. (150 mm) = 30 in. (76 cm) from
nearest valve or flow restriction. This requirement applies to
both stale air to exchanger duct and fresh air to house duct.
Before balancing, make sure:
• all sealing of the ductwork system is completed.
• all of the ventilator system components are in place and
functioning properly.
• balancing dampers are fully open.
• unit is on High speed.
• airflows in branch lines to specific areas of house are
adjusted before balancing the unit. (A smoke pencil used at
the grilles is a good indicator of relative airflow for each
branch line.)
After taking readings in stale air and fresh air ducts, duct with
lower cfm (L/s) velocity reading should remain as is, while duct
with higher reading should be dampered back to match lower
reading. See Fig. 10.
Return unit to appropriate fan speed for normal operation.
STARTUP AND CHECKOUT
After installation is complete, check to be sure system is
working correctly. Turn speed-selection knob to desired
position to set continuous background ventilation rate. Activate
two-wire control devices in system to make sure devices switch
ventilator to High speed. For operating instructions, see
instructions packed with digital fan timer. Leave instructions
with homeowner.
68-0285
Fig. 10. Balancing airflow.
SERVICE
CAUTION
Electrical shock hazard.
Can cause personal injury or equipment damage.
Disconnect power to unit before starting maintenance.
For maximum efficiency, the Fresh Air Ventilation System must
be maintained on a regular basis. Honeywell recom-mends
checking and cleaning at least twice a year, preferably at the
beginning of each heating and cooling season.
Cleaning Filters and Core
Remove the room air filter, fresh air filter and heat transfer core
from the ventilator as a unit.
1. Open ventilator door by loosening draw latches on top of
unit and swinging door open. For easier access, remove
door by moving it right to disengage hinges.
2. Carefully grip ends of core, (be careful not to damage
aluminum fins); then pull evenly outward. Core fits tightly,
but slides out of channels.
3. Once core is removed, filters can be removed by remov-
ing clips holding them in place. Note clip installation for
reassembly.
4. Wash the filters and the core in warm soapy water. Do
not wash them in a dishwasher.
5. Place the clean filter (wet or dry) over the core and
secure it in place with the clips.
6. Reinstall core by sliding it into the four corner channels.
(Water cannot damage gasket and label on core ends,
so it is not necessary to remove them from the core.)
Inspecting Exterior Hoods
Inspect exterior hoods at least monthly. Be sure exhaust and
fresh air supply hoods are not blocked or restricted by leaves,
grass or snow. In winter, be sure snow does not block hoods
and frost does not accumulate on wire mesh bird screen.
IMPORTANT
Blocked hoods can cause house/building pressure
change that can lead to possible combustion product
spillage from heating appliances.
10
PUSH AND TURN WITH
SLOTTED SCREWDRIVER.
DAMPER AUTOMATICALLY
LOCKS WHEN PRESSURE
IS RELEASED.
M13462
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