Renewable Energy Installer December/January 2014 | Page 28

Knowledge: Heat pumps
Future-proofi ng for renewables
With the diffi cult economic climate continuing to affect consumer spending,
installing underfl oor heating (UFH) and a heat pump at the same time could prove
beyond some domestic customers’ means. One solution for installers facing this
issue is to design UFH with the option of integrating a heat pump at a later date,
explains Steve Nixon, Nu-Heat’s operations manager
he launch of the Green Deal and
publication of proposed RHI tariffs
will inevitably mean that interest
in renewables increases although
not all customers will be able to afford to
install both underfl oor heating and a heat
pump in one go. However, if the UFH system
is designed for the existing heat source but
with the option of adding a heat pump at a
later date, it presents an ideal opportunity for
installers to secure future business.
T
Rising to the challenge
Future-proofi ng the UFH for use with a heat
pump presents a challenge. On the one hand
a boiler-fed heating system will be capable
of providing high water fl ow temperatures
and enough heat to ramp up and down, on
the other hand the heat pump will operate
most effi ciently when supplying lower fl ow
temperatures and running constantly. This
can be overcome by an experienced system
designer with an understanding of the design
parameters for both technologies; it is not a
standard design and should always be tackled
by a professional company.
A good supplier will offer advice as to
whether the property is suitable for underfl oor
heating and/or a heat pump. Both will always
be suitable in a new-build and UFH can be
used in most buildings that have been built
within the last 20 years or have had insulation.
Stringent criteria
However, the criteria for a heat pump are more
stringent meaning a detailed assessment
of the building’s heat loss will be needed
to determine whether or not a heat pump
will provide suffi cient energy to heat it
successfully with UFH. Nu-Heat knows that
design is crucial to performance and has
developed tools to ensure the correct sizing of
28 | www.renewableenergyinstaller.co.uk
Looking ahead: Although an effective way to secure future business, making UFH compatible with
the introduction of a heat pump at a later date requires an experienced system designer
a heat pump in accordance with the MIS3005
design standard.
When the heat pump is eventually
fi tted, the low fl ow temperatures required
by the UFH will allow it to operate at its
optimum effi ciency, achieve a good Seasonal
Performance Factor (SPF) and keep running
costs to a minimum.
To allow a smooth
transition between the
boiler and heat pump,
the installer should make
sure that key components
are accessible
Retrospective integration
Integration of the different technologies
is potentially complex. To allow a smooth
transition between the boiler and heat pump,
the installer should make sure that key
components (such as the blending valve) are
accessible, as they will have to be changed
when the heat pump is fi tted at a later date.
Any heat pump system should be
supplied with detailed drawings showing all
mechanical pipework and valves, electrical
schematics and installation manuals tailored
to the individual model. When this design
is then linked to a similar set of documents
showing how the UFH should be integrated
both mechanically and electrically, plus how
to install it into the fl oor construction, the
installation process is greatly simplifi ed.