gledhill TEC140-OV Installation & Servicing Instructions Manual page 22

INSTALLATION
HP Model With Central Heating From Heat Pump
3-port
diverter
valve
PRV
HP Model With Central Heating From Thermal Store
PRV
TORRENT ECO HP
Torrent Green HP Models
The Torrent ECO HP models are all open vented
and are designed to be heated directly by an
air or a ground source heat pump which does
not require a minimum pressure in the primary
Min. 250mm
circuit for operation. The space heating can be
supplied directly from the heat pump circuit or
from the thermal store.
The selection between the two options will
depend upon the operating characteristics of
the heat pump, type of heating system and
control strategy. For general guidance: -
• If the heat pump requires a buffer for
operation; for example to reduce rapid
cycling etc, then the system would benefit
if the heating system is supplied from the
thermal store. In this configuration, the
operation of the heat pump is only controlled
by the store thermostat(s).
• A hybrid system arrangement can also
be used (not shown). For example; a low
temperature weather compensated heating
circuit e.g. under floor heating can be
supplied directly from the heat pump circuit
and constant temperature e.g. towel rails
can be supplied from the thermal store.
A typical wiring arrangement for a system in
which the space heating is supplied from a
Torrent ECO HP is shown on page 34 and a
typical wiring arrangement for a system in
which the space heating is supplied from a heat
pump circuit is shown on page 35.
On page 34, the control of heat pump is shown
Min. 250mm
with top and bottom thermostats to enhance the
performance of the heat pump by decreasing the
frequency of cycling. The heat pump is switched
on when both top and bottom thermostats are
calling for heat and is switched off when both
thermostats stop calling for heat. A two channel
programmer suitable for gravity hot water
system should be used with this arrangement.
On page 35, the generic wiring arrangement
is shown with a 3-port diverter valve with hot
water priority. If a 3-port flow share valve is used,
then the controls should be wired to provide
priority for hot water because the space heating
and the hot water heating may be operating at
different flow temperatures.
Technological advancement of heat pump
control systems is occuring at a fast pace and
the conrol systems supplied with the heat
pump can provide full control of the system. It
is also important to ensure that the minimum
head for the heat pump and the system pump
is as required by the heat pump manufacturer.
Please refer to the heat pump manufacturers
instructions to obtain further information.
Page 22