Nordyne TC060 Installation Instructions Manual Download

Page: 13 / 44

Figure 15. Equipment in a Confined Space

with all Combustion Air Drawn from the

Outside through Horizontal Ducts

Determining Nominal AC System
Capacity

In order to select the appropriate airflow for AC
operation the nominal system capacity must be
known. The nominal system capacity is
ALWAYS the nominal capacity of the outdoor
unit. In some cases the nominal system
capacity is not the same as the nominal capacity
of the indoor coil.

NOTE: In order to change the speed settings
for heating or cooling, power to the unit
must be disconnected before the new speed
will be effective.

Selecting the AC Cooling Airflow

The cooling airflow is selected by setting switches
1 through 4 on the motor control board located in
the blower control panel. Table 1 shows the
airflow values versus the airflow selector switch
settings, and the range of airflow settings
recommended for each nominal system capacity.

Selecting the Heating Airflow

The heating airflow is selected by setting
switches 5 and 6 on the motor control board
located in the blower control panel. Note that
switch 7 is not used for heating or cooling in
these furnaces. Therefore, switch 7 can be
either “on” or “off” without affecting the operation
of the furnace. Table 1 shows the airflow values
versus the airflow selector switch settings, and
the range of airflow settings recommended for
each heating capacity.

NOTE:

The airflow values (CFM) listed in the

tables are not dependent on duct static pres-
sure. The motor automatically compensates for
changes in duct static pressure (within the limits
of the motor).

VENTING AND COMBUSTION AIR
REQUIREMENTS

These condensing furnaces may be installed
with outdoor combustion air piped directly to the
furnace, or without such special piping. Codes
refer to the former as "direct vent" or "two pipe"
installation. Installation with air taken from
around the furnace is sometimes referred to as
"one pipe" installation - i.e. only the vent (ex-
haust) pipe is provided.

Provisions must be made for adequate supply of
air for combustion and ventilation. For United
States installations, the adequacy of air provi-
sions can be determined by consulting the cur-
rent version of the National Fuel Gas Code (ANSI
Z223.1/NPFA-54). For Canadian installations,
requirements are specified in the National Stan-
dard of Canada (CAN/CGA B149.1 & .2). Consult
local codes for special requirements.

An important consideration in selecting one or
two pipe installation is the quality of the combus-
tion air. Indoor air is sometimes contaminated
with various household chemicals which can
cause severe corrosion in the furnace combus-
tion system.

NOTE:

If the furnace is operated without ad-

equate air for combustion and ventilation, it may
not perform properly. Furnace components
may be strained by high temperature and could
fail prematurely.

Each opening
to outside
must be at least
1 sq. in. per 2000
Btuh of total input
rating.

12" Max

Total Input

Rating (Btu/hr)

40,000
60,000
80,000
100,000
120,000
140,000
160,000

Minimum

Free Area

(Each Opening)

20 sq. in.
30 sq. in.
40 sq. in.
50 sq. in.
60 sq. in.
70 sq. in.
80 sq. in.

Round Duct

Diameter

5"
6"
7"
8"
9"
10"
10"