tekmar 361 Mixing Control - Manual (Page 6)

Copyright © D 361 -
03/09
6 of 20
CHARACTERIZED HEATING CURVE
When used as a mixing reset control, the 361 varies the supply water temperature based on the outdoor air temperature. The control
takes into account the type of terminal unit that the system is using. Since different types of terminal units transfer heat to a space
using different proportions of radiation, convection and conduction, the supply water temperature must be controlled differently. Once
the control is told what type of terminal unit is used, the control varies the supply water temperature according to the type of terminal
unit. This improves the control of the air temperature in the building.
MIXING TARGET TEMPERATURE (MIX TARGET)
When used as a mixing reset control, the MIX TARGET temperature is calculated from the Characterized Heating Curve settings,
outdoor air temperature and optionally, indoor air temperature. When used as a setpoint control, the installer sets the MIX TARGET
temperature. The control displays the temperature that it is currently trying to maintain as the mixing supply temperature. If the control
does not have a mixing demand, “- - -” is displayed as the MIX TARGET.
Section B2: Installer
OUTDOOR DESIGN (OUTDR DSGN)
The OUTDR DSGN is the outdoor air temperature that is the typical
coldest temperature of the year where the building is located. This tem-
perature is used when doing heat loss calculations for the building. If a
cold outdoor design temperature is selected, the mixing supply tem-
perature rises gradually as the outdoor temperature drops. If a warm
outdoor design temperature is selected, the mixing supply temperature
rises rapidly as the outdoor temperature drops.
SETPOINT OPERATION (MIX TARGET)
For setpoint operation, set the OUTDR DSGN to OFF. The MIX TAR-
GET becomes the setpoint supply temperature that the control is to
maintain. The MIX TARGET temperature is set by the installer in the
ADJUST menu. An outdoor sensor is not required during this mode of
operation.
ROOM OCC & UNOCC (ROOM)
The ROOM is the desired room temperature for the mixing zones, and
it provides a parallel shift of the
Characterized Heating Curve. The room
temperature desired by the occupants is often different from the design
indoor temperature (MIX INDR). If the room temperature is not correct,
adjusting the ROOM setting increases or decreases the amount of heat
available to the building. A ROOM setting is available for both the occu-
pied (Day) and unoccupied (Night) modes.
TERMINAL UNITS
When using a Characterized Heating Curve, the control requires the selection of a terminal unit. The terminal unit determines the
shape of the Characterized Heating Curve according to how the terminal unit delivers heat into the building space (refer to Essay
E 003). The 361 provides for selection between six different terminal unit types: two types of radiant floor heat, fancoil, fin-tube
convector, radiator and baseboard. When a terminal unit is selected, the control automatically loads the design supply temperature
(MIX DSGN), maximum supply temperature (MIX MAX) and minimum supply temperature (MIX MIN). The factory defaults are listed
below. To change defaults, refer to section B3. If a default has been changed, refer to section A to reload the factory defaults.
150
°F (66°C)
170
°F (77°C)
OFF
MIX DSGN
MIX MAX
MIX MIN
Terminal Unit
190
°F (88°C)
210
°F (99°C)
100
°F (38°C)
High Mass Radiant
(1)
120
°F (49°C)
140
°F (60°C)
OFF
Low Mass Radiant
(2)
Fancoil
(3)
140
°F (60°C)
160
°F (71°C)
OFF
Fin-tube Convector
(4)
180
°F (82°C)
200
°F (93°C)
OFF
Radiator
(5)
160
°F (71°C)
180
°F (82°C)
OFF
Baseboard
(6)
Decreasing Outdoor Temperature
Increasing W
ater
T
emperature
cold
MIX INDR
MIX DSGN
warm
OUTDR
DSGN
Increasing W
ater
T
emperature
Decreasing Outdoor Temperature
MIX INDR
N
or
m
al
De
sig
n
ROOM
Ac
tu
al
Te
mp
.