Selecting The Control Strategy; Five Control Strategies - REMEHA iSense Installation And Service Manual

11.

Selecting the control strategy

11.1 Five control strategies

The iSense can be used as a weather-compensated controller
or as a room thermostat (room control). Five control strategies
are available:
1 RTC (Modulating) room control
The control measures the room temperature in the reference
room (the room where the thermostat is located) and calculates
the required flow temperature based on an intelligent control
system. The boiler works by modulating: it controls the output
on the basis of the flow temperature and return temperature
of the water. This allows it to operate as efficiently as possible
with as constant a water temperature as possible.
Room control can be used anywhere, unless you do not want
a single reference room to determine the temperature for all
the other rooms.
2 OTC Weather-compensated control
The control measures the outside temperature with
an outside temperature sensor. The controller has
a programmed heating curve. Based on the outside
temperature, the flow temperature is determined with the
help of the heating curve.
The heating curve must be chosen so that the least
favourable room can be efficiently heated even when the
outside temperatures are very low.
The measured inside temperature does not affect the control
of the boiler. The desired inside temperature is only achieved
with a correctly programmed heating curve and a correctly
designed system.
Normal outside conditions are also important: direct sunlight
or a strong northerly wind mean lower or higher heating
requirements respectively, but have no influence on the
supply of heat. This is why weather-compensated control
alone is insufficient, and adjustments have to be made in
each room with thermostat valves.
3 OTC + RT: weather-compensated with the effect of the
room temperature
The basis of this control strategy is the same as weather-
compensated control. The heating curve must therefore be
correctly entered. The heating curve is also shifted when the
measured room temperature deviates from the desired room
temperature. The degree of shift is influenced by the RT
effect setting, see paragraph 11.3.
The advantage of this control is that desired room
temperature changes can be anticipated quickly. The boiler
will remain off for longer for desired room temperature
changes downwards, and this is good for the energy
consumption.
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