Panasonic Aquarea WH-SDC09H3E5-1 - Page 44

82 Aquarea air-to-water heat pumps - Planning and installation manual - 01/2018
Planning
83
Aquarea air-to-water heat pumps - Planning and installation manual - 01/2018
Planning
!
IMPORTANT
The hot water requirement has the highest inuence on the degree of coverage of solar systems
for hot water preparation. A proven ratio between tank volume and collector area is between 50
to 80 litres per square metre of collector area.
Hot water circulation increases the heat requirement for the hot water preparation and can be
up to 100% of the heat requirement for hot water preparation if the connection distance is very
long. Hot water circulation pumps should therefore always be operated in a time- and tempera-
ture-dependent manner.
5.1.3 Dening the Heating Surface Temperature
The temperature of the heating surfaces in the design for normal outside temperature should
not be taken as higher than 55 °C. Surface heating with inow temperatures of 35 °C and radi-
ators with an inow temperature of 45 °C are recommended. When replacing heat sources with
burners in existing buildings for an Aquarea heat pump, reduce the inow temperature as much
as possible by using additional heat insulation and restoration measures. Conventional heat
sources with burners are operated with inow temperatures up to 75 °C. By adapting proper res-
toration measures, the old radiators can often continue to be used at a lower temperature and
thermal output For this purpose, check on the basis of conversion factors, whether the heating
capacity of the radiators sufces even at a lower inow temperature.
If it is not possible to reduce the inow temperature, the Aquarea HT series can also supply at
inow temperatures up to 65 °C.
5.1.4 Operating mode and establishment of the bivalence point
First, the desired operating mode of the heat pump must be dened (→ 4.3.2 Operating mode,
p. 22). In order not to over-dimension the heat pump and to save on costs, a bivalent mode is
preferred. Another heat source is hooked up below a dened outside temperature and the asso-
ciated heating capacity. This heat source can be integrated externally (e.g. a boiler or replace)
or internally through the E-heating element of the heat pump. If this is a heat source that uses
power for heat production, it is a mono-energetic operation.
The bivalent mode only supports the air-to-water heat pump if the outside temperatures are very
low. As this is the case only for a few days a year, the generated heat of the E-heating element
only amounts to a few percent of the totally generated amount of heat.
Bivalent parallel operating mode (mono-energetic) via the internal E-heating element heat
pump
100 %
-15 -10 -5 0510 15 20
Bivalence point
Maximum heating load
Power E-heating
element heat pump
Heat pump power
Outside temperature (°C)
!
IMPORTANT
The bivalence point is dened individually for each building (→ 5.1.6 Example: Calculation of
the total heat capacity required, p. 83). Due to the inverter technology, Aquarea heat pumps
can work efciently even below the nominal capacity, without clocking.
5.1.5 Establishment of the pipeline correction factor for split systems
The performance of the split systems with hydro-module or combination hydro-module falls in
proportion to the increase in length of the coolant pipeline. Depending on the nominal capacity
of the heat pump, the change in performance differs for the models with up to 7 kW nominal
capacity and the models with more than 7 kW nominal capacity (see the tables below).
Pipeline correction factors for split systems up to 7 kW nominal capacity
Length of coolant pipeline (single) up to 10 m up to 20 m up to 30 m
Pipeline correction factor 1.0 0.95 0.90
Pipeline correction factors for split systems above 9 kW nominal capacity
Length of coolant pipeline (single) up to 7 m up to 10 m up to 20 m up to 30 m
Pipeline correction factor 1.0 0.95 0.90 0.85
5.1.6 Example: Calculation of the total heat capacity required
The main requirements for the air-to-water heat pump are dened through the standard heating
load and the standard outside temperature. Moreover, however, the Energy Supply Company
will have to take into account the hot water preparation and possible locking times. The connec-
tion distances of the connection pipelines between outdoor unit and hydro-module or combina-
tion hydro-module or between compact device and building are to be respected, because long