IDEAL Logic - Basic Logic Air Functions; Domestic Hot Water; Space Heating; Anti-Legionella Function

User's
5
User Guide
5. BASIC LOGIC AIR FUNCTIONS
Domestic Hot Water:
If there is a domestic hot water (DHW) Cylinder installed and
the temperature of the DHW Cylinder is less than the Hot Water
setpoint, the primary heat pump circuit is activated and directed
(via the divertor valve) to heat the hot DHW Cylinder.
The Heat Pump will operate until the DHW Cylinder has reached
its setpoint. This function will always take priority over the space
heating system within the programmed time.
Note: Domestic Hot Water Heating and Space Heating functions
cannot operate simultaneously
Space Heating:
If there is a heating demand and the temperature of any
thermostat is less than its setpoint, the primary circuit is activated
and directed (via the divertor valve) to heat the space heating
circuits. The Heat Pump and primary heating circuit circulator will
be active until the space heating has reached its setpoint.
Note: Domestic Hot Water Heating and Space Heating functions
cannot operate simultaneously
Anti-Legionella:
If there is a DHW cylinder installed, Anti-Legionella measures
should be utilised in accordance with HSE guidance HSG274
Part 2. The control system is provided with an Anti-Legionella
function for the DHW cylinder, the default parameter, which is
adjustable according to the installation and user requirements,
initiates this function once per week and heats the DHW cylinder
to 60°C for a period of 1 hour.
Logic Air Monobloc ASHP Defrost Method:
During operation, the Heat Pump will periodically be required
to go through an automatic defrosting process dependant on
the outdoor air temperature and humidity levels. Over time
the evaporator will begin to collect water which will then frost.
The defrost process causes the accumulated frost to thaw and
change to liquid. This liquid water then collects in the base panel
and ows through into the condensate drain openings located
on the base panel of the Heat Pump. Dependent upon the
installation type, the water will drain to ground or a dedicated
drainage point.
Cold Start Function:
With the Heat Pump in Standby Mode, if at any time a
heating demand is initiated and the primary heating circuit
water temperature is below 17oC, then the Heat Pump will
not commence operation. As at these water temperatures,
deterioration of the appliance may be caused upon start-up.
The Cold Start Function automatically enables and uses
alternative energy sources, dependent upon the installation,
to heat the primary heating circuit allowing the heat pump to
resume operation.
Dependent upon the system conguration the following solutions
may provide this function.
System with DHW Cylinder:
If there is a DHW cylinder installed, during this event, the Heat
Pump circulator pump and DHW cylinder back up heater will
operate only to increase the primary circuit water temperature.
Once 22 °C is achieved the DHW back up heater will be
terminated, and normal Heat Pump operation may then resume.
No DHW Cylinder:
If no DHW cylinder is installed, a supplementary back up
immersion heater installed within the primary heating circuit must
be tted to provide this function. In this event the supplementary
back up heater will operate in the same way detailed above and
heat the primary heating circuit water to 22 °C, at which point the
supplementary back up heater will be terminated, and normal
Heat Pump operation may then resume.
Combi - Boiler Back Up:
When using a combustion Combi-Boiler conguration with no
DHW cylinder, the boiler will operate to provide this functionality.
In this event the boiler will operate in the same way detailed
above and heat the primary heating circuit water to 22 °C, at
which point the boiler operation will be terminated and normal
Heat Pump operation may then resume.
Frost Protection (Appliance):
Note: Only if the appliance is in standby mode and with no DHW
or space heating demand.
If the outdoor air temperature is ≤ 1°C, Plant Frost Protection
will be initiated. During this event, the Heat Pump circulator
pump and central heating zone pumps (if applicable) will operate
continuously to prevent the primary heating water from freezing.
If the outdoor air temperature is ≤ 1 - 5°C, Plant Frost Protection
will be initiated. During this event, the Heat Pump circulator
pump and central heating zone pumps (if applicable) will operate
intermittently to prevent the primary heating water from freezing.
Frost Protection (Condenser):
If the primary circuit water temperature is ≤ 4 °C and the
Heat Pump has power but is in Standby Mode i.e., no DHW,
CH or Anti-Legionella demand, Condenser Frost Protection
will be initiated. Firstly, the Heat Pump circulator pump will
initiate, if after a dened time period, the primary circuit water
temperature is still ≤ 4 °C the backup heater will initiate to raise
the temperature to 22 °C. Once this temperature is achieved
the backup heater will be terminated and normal Heat Pump
operation may then resume. Note: The backup heater utilised
in this mode will depend upon the system conguration (refer
to Section 2.7.6 Cold Start Function on page 22 for available
solutions).
Frost Protection (Dwelling):
If the temperature of the dwelling is ≤ 8 °C, the room frost
protection mode will be initiated to prevent damage to the central
heating system. During this event, the Central Heating zone
pumps will be operated intermittently.
Weather Compensation:
Weather compensation regulates and maintains optimum ow
temperatures which allows the heat pump to run more e󰀩ciently.
This function will modulate the water ow temperature relative
to the external ambient temperatures. The lower the outdoor air
temperature, the higher the ow temperature and vice versa.
There are two types of weather compensation available and as
described below:
Weather Compensation Alone:
With this mode selected, the primary ow temperature is
calculated based on a heating curve, depending only on the
average outside temperature. The weather compensation
function is initiated with a permanently enabled outdoor
temperature sensor (QAC 34) supplied with the Heat Pump
system.
Combined Weather Compensation & Room Compensation:
With this mode selected, the primary ow temperature is
calculated based upon a heating curve and dependent upon the
ambient air temperature and the dwelling room temperature.
The current room temperature and its variation from the actual
setpoint is acquired and considered when controlling the heat
pump ow temperature. This way, consideration is given to
room temperature deviations, ensuring more accurate room
temperature control and optimum e󰀩ciency.