WESTPOINT Commercial Air conditioners
INVERTER VRF COMMERCIAL A/C
Contents
1
2
What’s WMV & VRF?
Residential central air AC
3
WMV energy consumption analysis
4
Digital scroll VS Inverter
Part ⅠGMV & VRF
Review of VRF(VRV)
 Variable Refrigerant Flow
 Developing from traditional split type air conditioner.
 Consist of outdoor units, indoor units, Refnet, controller
etc.
 One outdoor unit can drive at least 16 indoor units, with
which different capacity and appearance.
 Applied intensively in office building, hotel, high grade
department, villa etc.
Introduction of GMV
W– WESTPOINT
M – Multi-connected (Max. 1:32)
V – VRF system
2 ways to achieve VRV
Inverter
Originating from Japan, frequency
conversion;
Electrical adjustment;
Rotor
Reluctance motor
Digital scroll
Technology from Copeland;
Mechanic adjustment;
E.G. WMV in office building
Combination
with
Outdoor fresh
air processor
Part ⅡResidential central air conditioner
When central AC enter residential area…
Virtues of Central Air Conditioner
 Central air conditioner-centralized processing、distributing；
 Baring comparatively higher EER, more energy saving;
Residential Central Air Conditioner
 More comfortable, lower noise, less vibration, more accurate
adjustment;
Types of residential central AC
 Duct type
 Mini chiller
 WMV
Family of residential central AC
1. Duct type
•
Low initial investment;
•
Indoor air quality improve by introduction of
fresh air
•
Require enough height to layout the duct;
•
Individual adjustment for single room not
available
Mini Chiller-Hydraulic system
2. Mini Chiller
•All-Water system (water or ethylene alcohol);
•Adopt Fan coils as terminals, space saving;
•Without fresh air introduction;
•Individual control for each room available;
E.G. WMV in detached house
3. WMV
• Energy-saving;
• Low initial investment;
• Comfortable & Accurate;
• Individual control;
Figure: Ratio of VRV application in Japan
Old building
redecoration
New facility
Part Ⅲ WMV energy saving analysis
New orientation in working concept
Adopting digital scroll compressor
Core factors
Saving energy
Using refrigerant as heat transfer medium
Sophisticated controlling network
Combination with heat recovery processor
1. New orientation in designing concept
Traditional
designing base
on the most
sever outdoor
condition.
Peak of EER/COP
sets at partial
load. (around 40%
of the full load)
Ratio of cooling load throughout one year %
Cooling
load (%)
Working
time (%)
Cooling
load (%)
Working
time (%)
100
1
50
45
75
42
25
12
Data originate: American Society of Heating, Refrigerating
and Air-conditioning Engineers. (ASHRAE)
2. Adopt digital scroll compressor
Traditional residential split type AC adopts Rotary type compressor;
The efficiency of Scroll type compressor is higher than Rotary type or
Reciprocal type compressor;
Energy consumption can be reduced by 10-15% compared with the
reciprocal type at the same capability;
Comparing Items
Scroll type
Rotary type
Reciprocal type
EER
2.9
2.4~2.6
2.2~2.6
Volumetric efficiency
0.99
0.94
0.7
Adiabatic efficiency
0.98
0.93
0.88
Num. of part in
compression chamber
1
3
7
Weight ratio
0.8
0.8
1.0
Machining precision
1~3
3
10~30
Output power
1~10
0.4~1
1~10
Core component of digital scroll
Variable Capacity Adjustment is achieved by PWM (Pulse-WidthModulation) valve
“Fixed Scroll”
Discharge Pipe
by-pass pipe
Suction Pipe
Loading
Orbit Scroll
Gap: 1mm
between two
scrolls!
Idling
Adjust capability output
Pulse-width: Maintain a balance
between Demanding and Providing;
“Digital”: loading-100%(1), while
Idling-0%(0), forming the sequence
Cooling Capacity
0 1 0 1 0 1 0 1 0 1 0 1 0 1 …..
Digital Multi Unit
Inverter Unit
Capacity Demanded
3. Using refrigerant as heat transfer medium
 In GMV, heat transferred via refrigerant directly;
 The heat amount transferred can be 10 times of those transferred by
water, and 20 times via air.
 Comparing: Property of heat transfer medium
Types of
medium
Utilized heat
Transfer amount
Energy consumption
(transfer 120 kW
cool load)
Water
sensible heat
20.1kJ/kg (△t=5℃)
4.8
Air
sensible heat
10.1kJ/kg (△t=10℃)
7.5
Refrigerant
evaporating
latent heat
206kJ/kg
2.6
54% of those transfer via water;
35% of those transfer via air;
4. Sophisticated intelligent controlling
 Controlling Object
 Forming the network
 Sensors (temperature, pressure);
 Throttling devices (electrical expansion valves, pore plates);
 Advanced logical algorism;
 Basic principle
5. Combination with heat recovery processor
To improve the IAQ, people can open the windows sometimes, or
install a ventilating fan connect to outside;
But cooling load would rise, and unfiltered air with instable and
unreliable factor would penetrate in.
The Fresh Air Heat-Recovery System can solve this problem
• Introduce more filtered fresh air into the room;
• Recycle heat or cooling; (efficiency 75%)
• Reduce the amount of poisonous released from the building material;
The air route inside the system
1. Excellent water absorbability
exchanging efficiency reaches 75%;
2. Super fire-retardant
Safe and reliable
3. Mildew-proof, clean & healthy.
Exhaust air
Returning air of
indoor
Suction of
outdoor air
Cooled fresh air
introduced in
Compared to traditional way of ventilation, Fresh air
processor reduces 28% of energy consumption!
Part Ⅳ Digital scroll VS Inverter
Capability
adjustment
Digital scroll
Cooling Capacity
Comparing
items
Inverter
Digital Multi Unit
Inverter Unit
Capacity Demanded
Common Inverter comp.
Digital only
Digital & common parallel
connection
SEER
Electromagnetic
interference
Capacity Shift
By-pass of
refrigerant
Can be omitted
Sever disturbance, expensive
electromagnetic-proof apparatus
must be installed;
Shift to 100% capability
immediately
Must have procedure of
frequency conversion
No need
Have to install
Summary
WMV can be applied intensively in office
building, hotel, luxury department, villa, etc.
Enjoy a high EER/COP under partial load;
Combination with fresh air processor, can
improve IAQ & saving energy (up to 30%);
Digital scroll type VRF is more reliable and
flexible than Inverter.