Real Alternatives
... were among the earliest refrigerants used for mechanical cooling systems. (Choose 3)
When the ozone depleting refrigerants were phased
out R290 and other hydrocarbons started to be used
again. At the same time HFC refrigerants were
introduced and widely used, but their high
global warming potential coupled
with...
The typical applications of R744 are
The typical applications of R717 are
The typical applications of R600a are
Flammable refrigerants are categorised
as having either lower of higher flammability,
dependent on the concentration required
for ignition to be possible, the heat of
combustion and flame propagation.
Lower flammability does not mean...
Refrigerant application is often limited by
R744 has high operating pressures, a low
critical temperature (31OC) and a high triple
point. Its volumetric cooling capacity is
between 5 and 8 times that of HFCs,
reducing the required compressor
displacement and pipe size.
Its properties have an effect on how
the system is designed and operates,
especially in high ambient temperatures.
It has...
R744 is used in the following system types:
(Choose 3)
There are four equipment location classifications:
Class I –all mechanical equipment is located within
the occupied space; Class II – compressors are in a machinery room or
in open air; Class III – all refrigerating equipment is
in a machinery room or the open air;
Class IV –
Compression ratio is ...
EER or Energy Efficiency Ratio can also be
used to compare efficiencies in ... This is the ratio of the cooling capacity of
an air conditioner in kW or BTU per hour,
compared to the total electrical input in kW
or Watts at a given test criteria.
The direct global warming potential (GWP) of
the alternative refrigerants should not be
considered in isolation when selecting a
refrigerant for a particular application.
The impact of the refrigerant’s GWP is...
The total impact of a system and refrigerant on climate change is estimated using TEWI -
There are many ways TEWI can be minimised, including:
(Choose 3)
TEWI is calculated as follows: TEWI =
Whatever refrigerant is used leak
potential should be minimised.
Low GWP alternative refrigerants
usually have hazards associated
with high pressure, flammability or
toxicity, so leakage is a safety concern.
In addition – any leaking system consumes
... power and so has a ... indirect
impact on climate change.
What is an HFO:
What is the maximum charge of R290 that can be used on a supermarket shop floor (occupancy category A)
Which alternative refrigerant has the highest GWP:
According to EN 378, what is the max
refrigerant charge of a R290 direct
expansion system cooling a walk in
room (size 5x4m high 2.5m) and having
compressor, condenser, receiver
outside the room?
Створюйте онлайн-тести
для контролю знань і залучення учнів
до активної роботи у класі та вдома
