Air conditioning 2 Refrigeration
is 35 per cent greater than R22. It also has an ozone-
depleting potential of zero and is classed as an A1
refrigerant, meaning it is neither flammable nor
toxic.
‘Finally, R410A has a decreased compressor
displacement of 30 per cent, so the compressor does
not have to work as hard and is therefore likely to last
longer.’
Significant technological developments in inverter
drives and heat pump technology mean that older
forms of air conditioning – including those running
on R22 – run less efficiently than the systems available
today. According to Daikin, an increase in efficiency
of more than 30 per cent can be achieved with R410A
inverter air conditioning, compared with older
equipment running on R22.
Opting for a retrofit approach – replacing the main
aircon units but retaining existing pipework and so on
– also brings a significantly lower installation cost and
less disruption than would be the case from complete
replacement of an existing R22 system. It also avoids
the risks and uncertainties around the cost and quality
of recycled supplies of R22. l
www.defra.gov.uk/fgas
Retrofitting with an
Technology Four approaches to R22 replacement/renewal
alternative refrigerant
overcomes the need to
Sanyo Air Conditioners’ R22 Renewal system is potentially, controllers and indoor units installed since replace existing equipment.
designed to be used with existing Sanyo systems 1996, to be retained so only the outdoor units and
and most types of R22 systems from other leading heat recovery BS branch selector boxes need to be
manufacturers. It uses existing refrigerant pipework replaced. VRV-Q is designed to operate at the lower
to speed up installation and cut replacement costs by pressures required by existing R22 piping without
around 30 per cent, the company says. It also delivers compromising efficiency. During system recharging,
running-cost savings due to the increased energy new R410A refrigerant circulates through the copper
efficiency of R410A equipment – with CoPs of up to piping and collects residual contamination. The
four, compared with 2.5 and below for R22 systems. refrigerant, including the remaining oil from the R22
On most installations, existing wiring can also be system, is filtered in the outdoor unit in which the
used, although flare connections are replaced to contamination is also then deposited. This process is
accommodate the higher working pressures of R410A. only done once and generally takes about an hour.
R22 renewal can also be applied to existing R407C
Making use
systems. Toshiba R22 replacement systems – Digital and Super
of existing
Digital Inverter – use R410A refrigerant. By re-using
pipework is now
Mitsubishi Electric’s ‘Replace’ technology allows existing services such as the pipe work, Toshiba
R22 systems to be upgraded using existing pipe Carrier claims that it typically saves 37.5 per cent on
a viable and
work without the need to apply any special cleaning installation cost and 30 per cent on installation time.
cost-effective
machines. This technology uses Mitsubishi Electric Digital Inverter and Super Digital Inverter systems
alternative –
patented Hard Alkyl Benzene oil, claimed to be more are said to reduce energy costs by at least 40 per cent
tolerant of contamination. By combining this oil compared with older R22 systems ‘and, in many,
Graham Wright
with developments in oil separator technology, it is cases this percentage can increase to almost 75 per
possible for the inverter models to use existing pipe cent’. Toshiba compared the cost of an old R22 split
work without any special operations. Mitsubishi system and a new R410A system based on installing
Electric has launched a range of Mr Slim models two new ceiling cassette systems on to an existing R22
incorporating Power Inverter technology for small- to installation system using the old pipework. The supply
medium-sized applications with ‘Replace’ technology and installation of all the equipment was £4,875.
to allow for easier upgrade from existing R22 systems. This compared with £7,800 had the existing services
been stripped out and replaced with new. The R22
Daikin UK’s upgrade for VRV systems operating on fixed speed systems cost, on average, more than £11
R22 refrigerant – VRV-Q – uses R410A refrigerant per day in January – whereas the new R410A Digital
and is said to allow all existing VRV R22 piping and, Inverter system was just over £4.
www.cibsejournal.com March 2010 CIBSE Journal 49
CIBSEmar10 pp48-49 Refrigeration.indd 49 25/2/10 16:11:58
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