Mitsubishi Electric ecodan PUHZ-W50VHA2 User Manual page 18

Installation
Ecodan Primary Circuit
The Ecodan primary circuit must be unvented due to the concentration of anti-freeze required in the pipework.
Flexible hoses are supplied with the package which should be installed to connect the Ecodan to the system
pipework to prevent resonance into the fabric of a property. The flow pipe from the Ecodan should be connected
to the top connection of the external plate heat exchanger. All primary pipework from the Ecodan to the cylinder
should be fully installed using Armaflex or similar. All joints should be taped and either weather-wrapped or put
into trunking.
Central Heating Circuits
These should be sized in the normal way to suit the flow and return temperatures for the required system.
Balancing of a radiator circuit is essential to achieve the best performance from an Ecodan.
If the Ecodan is being fitted to an existing heating system, this must be thoroughly flushed/cleaned before the
appliance is installed.
Plastic Pipework
Plastic pipework can be used internally as long as it is recommended by the manufacturer and installed in
accordance with their recommendations. Barrier type plastic pipework should always be used for these systems. It
is important to ensure that if the system is installed using plastic pipework, it is designed and sized using the
characteristics for plastic pipework.
Cylinder Specification
As a rule of thumb for the average household application the following combinations can be used, however please
note these are for guidance only and must be checked by the designer and installer beforehand.
To achieve good system efficiencies higher flow rates are recommended. Using a larger cylinder than
recommended will not cause the system to malfunction but will affect the efficiency of the system. A small heat
pump having to heat up a large cylinder will take longer than necessary and will effect the homeowners running
costs.
Due to the low flow temperatures supplied by the Ecodan the type of domestic hot water cylinder used in
conjunction should meet a certain criteria to achieve the best possible performance and efficiencies.
Ecodan Unit
Circulating Pumps*
Minimum Flow Rate
System
Requirements
Maximum Flow Rate
Pipework
Minimum coil surface area
Cylinder
Material
Requirements
Capacity**
*Pump sizes will vary with application, these are general guideline sizes only.
**General guideline sizes giving acceptable heat up times with the respective unit and providing
the property with adequate hot water storage.
16
INSTALLATION
PUHZ-W50VHA-BS PUHZ-W85VHA(2)- BS PUHZ-HW140VHA(2)-BS
2 x 15/50
6.5 l/m
14.3 l/m
22mm
2m²
Copper
Up to 180 L
15
2 x 15/50
10 l/m
25.8 l/m
22mm
3m²
Copper
Up to 210 L Up to 300 L
2 x 15/60
17.9 l/m
40 l/m
28mm
3m²
Copper
Table 1.2