Panasonic Aquarea WH-SDC16H6E5 - Determination of the Pipe Length Correction Factor for Bi-Bloc Systems; Example: Calculation of the Total Heating Capacity Required

95
Aquarea air-to-water heat pumps - Planning and installation manual - 02/2022
Planning
5
Bivalent parallel operating mode (mono-energetic) via the heat pump’s internal electric
backup heater
100 %
-15 -10 -5 0510 15 20
Bivalence point
Maximum heat load
Heat pump’s electric
backup heater
Heat pump power output
Outside temperature (°C)
!
IMPORTANT
The bivalence point is dened individually for each building (→ 5.1.6 Calculation example: total
heating capacity required, p. 95). Due to the inverter technology, Aquarea heat pumps can work
e󰀩ciently even below their nominal capacity, without cycling.
5.1.5 Determination of the pipe length correction factor for bi-bloc
systems
The performance of bi-bloc systems with hydrokit or All in One indoor unit falls in proportion to the
increase in length of the refrigerant pipe. Depending on the nominal capacity of the heat pump, the
decrease of performance di󰀨ers for the models with up to 7 kW nominal capacity and the models
with more than 7 kW nominal capacity (see the tables below).
Pipe length correction factors for bi-bloc systems up to 7 kW nominal capacity
Length of refrigerant pipe (one way) up to 10 m up to 20 m up to 30 m
Pipe length correction factor 1.0 0.95 0.90
Pipe length correction factors for bi-bloc systems above 9 kW nominal capacity
Length of refrigerant pipe (one way) up to 7 m up to 10 m up to 20 m up to 30 m
Pipe length correction factor 1.0 0.95 0.90 0.85
5.1.6 Example: Calculation of the total heating capacity required
The main requirements for the air-to-water heat pump are dened through the design heat load
and the design outside temperature. Moreover, the domestic hot water demand and electricity
shutdown times imposed by the electric utility company must be taken into account. Also, the
length of the connection pipes between outdoor unit and indoor unit (hydrokit or All in One unit) or
between mono-bloc unit and the building are to be considered, because long pipes lead to a lower
heating capacity. And not the least, besides the heat pump power, the supply water temperature at
design outside temperature is also decisive for selecting the right heat pump.
On the other hand, Aquarea heat pumps have an internal electric backup heater, which can provide
additional heating capacity while outside temperatures are very low.