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© 2010 D 270 - 08/10
BOIL MAX
BOIL DSGN
OUT DSGN
ROOM OCC
ROOM UNOCC
210
(99)
190
(88)
170
(77)
150
(66)
130
(54)
110
(43)
90
(32)
70
(2
50°F
(10°C)
-20
(-29)
0
(-18)
20
(-7)
40
(5)
60
(16)
80
(27)
Outdoor Air Temperature
Supply W
a
ter T
e
mperatur
e
Boiler Characterized
Heating Curve
Boiler Characterized
Heating Curve
BOIL MIN
BOIL INDR
WWSD OCC
WWSD UNOCC
CHARACTERIZED HEATING CURVE
The control 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, natural convection
and forced convection, the supply water temperature must be controlled
differently. Once a terminal unit is selected, 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.
BOILER DESIGN TEMPERATURE
The boiler design supply temperature is the supply water temperature
required to heat the building when the outdoor air temperature is as cold
as the outdoor design temperature.
BOILER INDOOR DESIGN TEMPERATURE
The indoor design temperature is the room temperature that was used in
the original heat loss calculations for the building. This setting establishes
the beginning of the characterized heating curve.
ROOM
The
Room
setting is the desired room temperature for the building and provides a parallel shift of the heating curve. The room
temperature desired by the occupants is often different from the design indoor temperature. 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 occupied (day) and unoccupied (night) periods.
INDOOR SENSOR
With the indoor sensor connected, the control is able to sense the actual room temperature. Indoor temperature feedback fine-
tunes the supply water temperature in the heating system to maintain room temperature. To adjust the room temperature, use the
Room Occ
or
Room UnOcc
setting in the ADJUST menu at the control.
The indoor sensor is connected to the
Indr
and
Com
terminals (17 and 18). In addition, power must be applied to the
Boiler Demand
terminals (1 and 2) as described in the Boiler Demand section.
If a multiple zone system is used with an indoor sensor, proper placement of the indoor sensor is essential. The indoor sensor
should be located in an area which best represents the average air temperature of the zones.
TERMINAL UNITS
The control provides for a 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,
maximum supply temperature, and minimum supply temperature. The factory defaults are listed below. These factory defaults can
be changed to better match the installed system.
Terminal Unit
High Mass
Radiant (1)
Low Mass
Radiant (2)
Fancoil
(3)
Fin-Tube
Convector (4)
Radiator
(5)
Baseboard
(6)
BOIL DSGN
120°F (49°C)
140°F (60°C)
190°F (88°C)
180°F (82°C)
160°F (71°C)
150°F (66°C)
BOIL MAX
140°F (60°C)
160°F (71°C)
210°F (99°C)
200°F (93°C)
180°F (82°C)
170°F (77°C)
BOIL MIN
OFF
OFF
140°F (60°C)
140°F (60°C)
140°F (60°C)
140°F (60°C)
High Mass Radiant (1)
This type of a hydronic radiant floor is embedded in either a thick concrete or gypsum
pour. This heating system has a large thermal mass and is slow acting.
Low Mass Radiant (2)
This type of radiant heating system is either attached to the bottom of a wood sub-floor,
suspended in the joist space, or sandwiched between the sub-floor and the surface.
This type of radiant system has a relatively low thermal mass and responds faster than
a high mass system.