Daikin EWAP460MBYN [246/452] Heat recovery

Functional Control for a Standalone Unit ESIE05-07

2–50 Part 2 – Functional Description

2.14 Heat Recovery

Introduction This function allows recovering heat from a cooling only unit. This is done by means of a second plate

heat exchanger and regulation on a higher high pressure setpoint.

This function is only available on air-cooled cooling only units with inverter fan management.

Defining the heat

recovery mode

The decision whether the unit works in heat recovery mode or not can be done in 2 ways:

1. Through a heat recovery mode switch (S6S field installed):

P When the heat recovery mode switch is closed, heat recovery is asked.

P When open, cooling mode is asked.

Note: It is clear that the cooling capacity and the cooling efficiency will be higher when the unit is

running in cooling mode. For this reason, we advise to use a external thermostat for S6S that switches

the unit automatically to the cooling mode when the target temperature of the hot water is reached.

The changeable digital input 1 is by default defined as “Heat recovery”.

2. Through the heat recovery thermostat function of the controller.

The heat recovery mode is controlled by the hot water temperature measured by an additionally

installed sensor R8T (EKCLWS) in the hot water.

To achieve this setting a changeable analog input must be defined as “HR inlet water c”.

Note:

P If the heat recovery thermostat function of the controller will be used and the heat recovery mode

switch will not be installed, then the changeable digital input 1, default defined as “Heat recovery”,

must be changed to “None”. (refer to service menu, screen changeable inputs”).

P If the heat recovery thermostat function of the controller will be used and the heat recovery mode

switch will not be installed, then the unit will only run in heat recovery when the heat recovery

themostat function requests heat recovery and when the heat recovery mode switch is closed

(AND function). Else the unit will run in cooling mode.

An additional sensor R8T (EKCLWS) must be connected directly to the PCB of the unit.

The units with heat recovery installed can also be used in a DICN setup.

P If the system is controlled on inlet water temperature, the 2 ways to define the heat recovery mode

are available on the master unit.

P If the system is controlled on outlet water temperature, the heat recovery mode can only be

controlled by the heat recovery mode switch on the master unit.

P On the slave units, the 2 ways to define the heat recovery mode are available.

ESIE05-07.book Page 50 Wednesday, October 11, 2006 10:42 AM