Technical
required operating ranges, due to the high discharge gas
temperatures. This is why refrigerant blends based on R32
and HFO with a higher proportion of R125 have also been
developed. The GWP is slightly above 2 000, but below the
limit of 2 500 set in the EU F-Gas Regulation from 2020.
The main advantage of such blends is their moderate
discharge gas temperature, which allows the operation within
the typical application limits of R404A. Tab 4 shows the
potential blend components for the alternatives described
above. With some refrigerants the mixture components for
R22/R407C and R404A/R507A substitutes are identical, but
their distribution in percent is different. In the meantime,
Chemours, Honeywell, Arkema, Mexichem and Daikin
Chemical have offered corresponding chemical variants for
laboratory and field tests, and in some cases already for
commercial use.
A number of refrigerants are still declared as being under
development and are only made available for testing purposes
under special agreements. Until now, trade names are often
used although a larger number of HFO/HFC blends are already
listed in the ASHRAE nomenclature.
Table 5 lists a range of currently available refrigerants or
refrigerants declared as development products.
Due to the large number of different versions and the
potential changes in development products, Bitzer has so far
tested only some of the new refrigerants. This is why for the time
being, only refrigerant properties of nonflammable alternatives
for R134a and R404A/R507A (GWP < 1500) are listed which have
already received an ASHRAE number and are commercially
available.
For testing the ‘Low GWP’ refrigerants, AHRI (USA) has
initiated the ‘Alternative Refrigerants Evaluation Program
(AREP)’. It was established to investigate and evaluate a series
of the products including halogen-free refrigerants. Some of
these are also listed in Table 5.
Table 4 and 5 available online.
Continued in the next issue of RACA Journal. RACA
EVENTS
With the disruption of the Covid-19 pandemic, many, if not
all events have been affected. Some organisers continue to
host virtual conferences and exhibitions and we advise that
you check regularly for any updates.
For local events/webinars/conferences, please contact
the associations directly to ensure accurate information.
The Fourth International Conference on Efficient Building
Design Materials and HVAC Equipment Technologies
October 01 - 02, 2020, Beirut, Lebanon
HUMOUR
THUMBS UP
Why did the construction worker dip his finger in blue ink?
To get a blueprint. RACA
FINAL FIX
Chillventa eSpecial: October 13 – 15, 2020
A virtual event will still continue this year although the main
event has been moved to 2022
RETA Conference (Refrigerating Engineers and
Technicians Association): October 27 – 29, 2020
Orlando, Florida, United States of America
14th Annual Conference on Advanced Building Skins
October 28 – 29, 2020, Bern, Switzerland
14th IIR-Gustav Lorentzen Conference on Natural
Refrigerants, December 06 – 09, 2020 | Kyoto, Japan
“Clearly a forgotten corner…”
Submit your ‘fixes’
Have you seen any interesting final ‘fixes’ lately?
(The good, the bad, and the downright illegal.)
Send them to [email protected].
50
RACA Journal I October 2020
www.hvacronline.co.za