Ventilation Evaluation - Bryant HRVBBLHA Installation Instructions Manual

balancing dampers while located in flexible duct. Insulating over
these dampers is strongly recommended after balancing is complete
to prevent condensation problems.
Flow Collar
Flow collars are temporary and should be installed as close to HRV
as possible and in straightest sections of duct to ensure accuracy
(see Fig. 16). If only 1 flow collar is available, install collar in
stale- -air duct of HRV, and record airflow. Next, install collar in the
fresh- -air duct and record airflow. If 2 flow collars are available, it
will be much easier to read airflow and properly adjust dampers to
balance unit.
With speed control at maximum speed (high- -speed operation) and
continuous air exchange occurring with outside, connect hoses
from flow collar to a magnehelic gauge (see Fig. 17). The gauge
must be leveled and zeroed before use to read accurately. If needle
falls below zero, reverse hose connections.
Measure exhaust air first, it is typically the lowest pressure due to
nature of system and duct work. Next, measure fresh air. If fresh air
reading is higher than exhaust reading, adjust damper until reading
is same. If reading is lower, return to exhaust damper and adjust to
obtain same reading. You can use label on flow collar to convert
static pressure into airflow.
Once HRV is balanced and dampers are adjusted to equalize
airflow, use tape or drive screws to prevent damper blades from
moving. Remove flow collars and secure ducts. This procedure
should be repeated to ensure unit is balanced properly.
NOTE: The flow collar directional arrow (on flow collar) must be
oriented in the airflow direction of unit.
NOTE: Some field modification may be required to ensure proper
temporary installation of flow collar during balancing when
insulated flexible duct is used.
WASH-
ROOM
MASTER
BEDROOM
BEDROOM
#4
WASH-
ROOM BEDROOM
#1 #2 #3
BEDROOM
#5
1320 sq ft (125 sq m)
BASEMENT
Fig. 18 - - Floor Plan Example

VENTILATION EVALUATION

CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in reduced unit
efficiency, capacity or unit life.
DO NOT use HRV during construction of a house or when
sanding drywall. This type of dust may damage system.
When ventilation requirement is determined, use Product Data
Sheets to reference unit airflow delivery and performance.
The ventilation capacity of an HRV unit while at maximum speed
is defined according to greatest total airflow required. These
methods are derived from the Canadian National Building Code
1995 version and the CSA F326.1 revision.
The following 2 methods can be used to evaluate the approximate
ventilation needs of a house. Accuracy of calculations are
dependent upon the information available and knowing critical
measurements of the structure (see Fig. 18).
METHOD 1
To calculate approximate ventilation:
The sum of rooms X 10 CFM per room, plus 20 CFM for a
master bedroom or basement.
Example: 11 rooms X 10 CFM + 2 X 20 CFM = 150 CFM.
NOTE: The master bedroom and basement are not included in
first part of this equation, but figured in at second part of equation.
METHOD 2
To calculate approximate ventilation:
Referencing same example (see Fig. 18).
Total cu ft X 0.3 per hr = total. Take total and divide by 60 to
get CFM.
Example:
1320 sq ft X 8 ft in height = 10560 cu ft per floor
10560 cu ft x 3 floors = 31680 total cu ft in house
31680 cu ft X 0.3 air change per hr = 9500 cu ft
9500 cu ft ÷ 60 minimum per hr = 160 CFM.
Conclusion: The total amount of air flow needed is 160 CFM. This
falls within airflow range of a HRVBBLHA1150 size unit.
WASH-
ROOM
#7
LIVING ROOM
#6
FAMILY ROOM
#10
1320 sq ft (125 sq m)
9
LAUNDARY
KITCHEN
ROOM
#9
#8
DINING ROOM
#11
1320 sq ft (125 sq m)
A98388