tekmar 264 Boiler Control - Manual (Page 10)

© 2008 D 264 - 12/08 10 of 32
OUTDOOR DESIGN TEMPERATURE
The outdoor design temperature is the outdoor air temperature that is the typical coldest temperature of the year where the building is
located. This temperature is used when doing the heat loss calculations for the building. If a cold outdoor design temperature is selected,
the boiler supply temperature rises gradually as the outdoor temperature drops. If a warm outdoor design temperature is selected, the
boiler supply temperature rises rapidly as the outdoor temperature drops.
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 IND
WWSD Occ
WWSD UnOcc
TERMINAL UNIT HIGH MASS RADIANT
(1)
LOW MASS RADIANT
(2)
FANCOIL
(3)
FIN-TUBE CONVECTOR
(4)
RADIATOR
(5)
BASEBOARD
(6)
BOIL DSGN
BOIL MAX
BOIL MIN
120°F (49°C)
140°F (60°C)
OFF
140°F (60°C)
160°F (71°C)
OFF
190°F (88°C)
210°F (99°C)
140°F (60°C)
180°F (82°C)
200°F (93°C)
140°F (60°C)
160°F (71°C)
180°F (82°C)
140°F (60°C)
150°F (66°C)
170°F (77°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.
BOILER DESIGN TEMPERATURE
The boiler design temperature is the supply water temperature required
to heat the building when the outdoor air temperature is as cold as the
outdoor design temperature.
WARM WEATHER SHUT DOWN
When the outdoor air temperature rises above the WWSD setting, the
control turns on the WWSD pointer in the display. When the control is in
Warm Weather Shut Down, the boiler demand pointer is displayed if there
is a boiler demand. However, the control does not operate the heating
system to satisfy this demand. The control does respond to a DHW or a
setpoint demand and operates as described in section E or F.
ROOM
The room 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 increase or decreases the amount of heat available to the building. A ROOM setting is available for both the
occupied (day) and unoccupied (night) periods.
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. If a factory default has been changed, refer to section A
to reload the factory defaults.