Ventilation Evaluation; Method 1; Method 2; Control Board Operation - Bryant HRVBBLHU Installation, Start-Up, And Operating Instructions Manual

MASTER
BEDROOM
BEDROOM
#4

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 depen-
dent upon the information available and knowing critical measure-
ments of the structure (See Fig. 26).

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. 26). Total cu ft X 0.3 per hr
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 airflow needed is 160 CFM. This
falls within airflow range of a HRVBBLHU1150 size unit.

CONTROL BOARD OPERATION

I. BOARD FUNCTION
NOTE: To ensure proper operation of HRV, configuration jump-
ers are located on electronic control board and must match
configuration setup shown on Fig. 27 and 28 under Jumper Table.
WASH- WASH-
ROOM ROOM BEDROOM
#1 #2 #3
BEDROOM
#5
1320 sq ft (125 sq m)
BASEMENT
Fig. 26—Floor Plan Example
= total. Take total and
divide by 60 to get
CFM.
—13—
WASH-
ROOM
#7
LIVING ROOM
#6
FAMILY ROOM
#10
1320 sq ft (125 sq m)
Jumpers are factory set and do not require any changes unless
control board is replaced. If control board is replaced, or you
encounter unusual start-up operation, check jumpers to make sure
they are located properly (See Fig. 27 and 28).
II. DEFROST
The HRV continually monitors the outside air temperature. If the
outside air is at or below 23°F(-5°C), the HRV will initiate a
defrost cycle by closing the outside air damper and re-circulating
warm indoor air through the heat recovery core. This happens
approximately every hr with 5 minute defrost cycle. During this
process, core is defrosted without the use of electric strip heat. At
5°F(-15°C), unit will defrost for 5 minutes every half hr. At
-22°F(-30°C), the unit will sense a need to defrost every 20
minutes with a 5 minute cycle. See the Troubleshooting section for
a control logic explanation.
III. OFF AND INTERMITTENT/OFF MODE
When HRV is Off, K1 relay is open, and K5 relay is energized
which closes outside air damper (See Logic Diagram in Fig. 27 and
28).
IV. HIGH-SPEED AIR EXCHANGE
When high-speed air exchange occurs, K1 and K2 relays are
energized and K5 relay is de-energized. This opens low-speed
contacts, and closes high-speed contacts on K2 relay. This also
opens contacts on K5 relay which opens outside air damper. Then,
115vac is applied between orange and gray wires on Molex plug
(pins 1 and 6) and blower motor runs in high-speed operation.
Also, 115vac is applied across pins 5 and 7, this energizes
interlock relay (See Logic Diagram in Fig. 27 and 28).
V. LOW-SPEED AIR EXCHANGE
When low-speed air exchange occurs, K1 Relay is energized
which closes the contacts. K2 and K5 relays are de-energized. This
keeps low-speed contacts closed and high-speed contacts open on
K2 relay, and opens outdoor air damper. 120vac is applied
between Red and Gray wires on Molex plug (pins 1 and 4) and
blower motor runs in low-speed operation. Also, 115vac is applied
across pins 5 and 7, this energizes interlock relay (See Logic
Diagram in Fig. 27 and 28).
LAUNDARY
KITCHEN
ROOM
#9
#8
DINING ROOM
#11
1320 sq ft (125 sq m)
A98388