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Copyright. SAI HVAC 2021
TM_VRAF_VAV12.19.001
3. VRF12 Operating Instructions Using the User Interface
1. Open the User interface using the steps mentioned in 2.1, 2.2 or 2.3
2. The page will open in the “Overview Screen”. (
Figure 14)
3. The overview screen is where you change all system wide values.
3.1 Changing the System Mode
Press the Auto, Heat, Cool or Vent Buttons.
(Figure 14
–
Yellow Arrow)
3.2 Notes on Dynamic Energy Recovery
Your SAI HVAC multi zone temperature control system modulates its output capacity to match the heat load. It
continues to cool or heat individual zones until they reach the target temperature (set point). When all zones
are at target temperature, the refrigeration cycle is switched off. On a system where dynamic energy recovery
is disabled, any room can re-activate cooling or heating when the temperature moves away from set point by
0.5°C. Dynamic energy recovery is a technology designed for structures that include a large central area
surrounded by perimeter rooms. The perimeter rooms lose and gain heat at a much faster rate than the
central area. The reason for this phenomenon is that the portion of external walls and roof to room volume is
significantly higher and the additional thermal mass of the central area reduces the rate at which heat is
gained or lost. The dynamic energy recovery algorithm intervenes when a perimeter zone calls for heating or
cooling, it then measures the return air temperature (positioned din the large central zone) to apply a
proprietary algorithm that calculates the flow needed to slow down the rate at which heat is gained or lost.
The slider allows the user to find the right balance for their home or building between energy reduction and
comfort. The slider moves the point at which the worst performing zone can terminate dynamic energy
recovery and force heating or cooling.
The VRF12 zoning control is a unique part of the SAI HVAC system that provides the ability to dramatically
reduce your energy bills. It is important to note that the average household uses 38% of their power bill on
heating and cooling. It is also important to note that every degree Celsius difference between the inside
temperature and the outside temperature adds 10% to the energy cost for that room. SAI HVAC
’s multi zone
temperature control system automatically adjusts the airflow to individual rooms to make sure that cooling
and heating overshot is eliminated. There are 3 additional energy settings that are use adjustable that
decrease energy use further. This feature is most often used in combination with occupancy sensors. When
applied in this fashion you can move through your home & the system automatically turns on and off as
required.
3.3 Set the Optional Countdown Timer
Slide the “Auto Off” slider to the desired position between 30 & 240 minutes. The Auto Off t
imer is only used if
you wish the system to run for that period of time and then switch off. The system then requires a re-start.
This feature is designed as a safe guard for properties where the air conditioning can be left on while not
required
. (Figure 14
–
Red Arrow).
Anytime there is an on event on the system in any zone, the system will
continue to operate. This feature is most often used in combination with occupancy sensors. When applied in
this fashion you can move through your home & the system automatically turns on and off as required.
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.4 Optional “Cooling” and “Economy”
Settings
See figure 14 (blue arrows), use the slider bar to change.
