2Contents 1 2 3 4 What’s WMV & VRF? Residential central air AC WMV energy consumption analysis4Digital scroll VS Inverter
3Part ⅠGMV & VRF Variable Refrigerant Flow Review of VRF(VRV) 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.
4WMV W– WESTPOINT M – Multi-connected (Max. 1:32) V – VRF system Introduction of GMVW– WESTPOINTM – Multi-connected (Max. 1:32)V – VRF systemWMV
52 ways to achieve VRV VRV Inverter Digital scroll Rotor Originating from Japan, frequency conversion;Electrical adjustment;Digital scrollTechnology from Copeland;Mechanic adjustment;RotorReluctance motor
6E.G. WMV in office building CombinationwithOutdoor freshair processor
7Part ⅡResidential central air conditioner When central AC enter residential area…Virtues of Central Air ConditionerCentral air conditioner-centralized processing、distributing；Baring comparatively higher EER, more energy saving;Residential Central Air ConditionerMore comfortable, lower noise, less vibration, more accurate adjustment;Types of residential central ACDuct typeMini chillerWMV
8Family of residential central AC 1. Duct typeLow initial investment;Indoor air quality improve by introduction of fresh airRequire enough height to layout the duct;Individual adjustment for single room not available
9Mini Chiller-Hydraulic system All-Water system (water or ethylene alcohol);Adopt Fan coils as terminals, space saving;Without fresh air introduction;Individual control for each room available;
10E.G. WMV in detached house Energy-saving;Low initial investment;Comfortable & Accurate;Individual control;
11Figure: Ratio of VRV application in Japan 60%32%Old building redecorationNew facility
12Part Ⅲ WMV energy saving analysis New orientation in working conceptAdopting digital scroll compressorCore factorsSaving energyUsing refrigerant as heat transfer mediumSophisticated controlling networkCombination with heat recovery processor
131. 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 (%)1001504575422512Data originate: American Society of Heating, Refrigerating and Air-conditioning Engineers. (ASHRAE)
142. 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 ItemsScroll typeRotary typeReciprocal typeEER2.92.4~2.62.2~2.6Volumetric efficiency0.990.940.7Adiabatic efficiency0.980.930.88Num. of part in compression chamber137Weight ratio0.81.0Machining precision1~310~30Output power1~100.4~1
15Core component of digital scroll Variable Capacity Adjustment is achieved by PWM (Pulse-Width-Modulation) valveby-pass pipe“Fixed Scroll”Discharge PipeSuction PipeLoadingGap: 1mm between two scrolls!Orbit ScrollIdling
16Adjust capability output Pulse-width: Maintain a balance between Demanding and Providing;“Digital”: loading-100%(1), while Idling-0%(0), forming the sequence…..Cooling CapacityDigital Multi UnitInverter UnitCapacity Demanded
173. 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 mediumTypes of mediumUtilized heatTransfer amountEnergy consumption (transfer 120 kW cool load)Watersensible heat20.1kJ/kg (△t=5℃)4.8Air10.1kJ/kg (△t=10℃)7.5Refrigerantevaporating latent heat206kJ/kg2.6PowerConsumption54% of those transfer via water;35% of those transfer via air;
195. 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 problemIntroduce more filtered fresh air into the room;Recycle heat or cooling; (efficiency 75%)Reduce the amount of poisonous released from the building material;
20The air route inside the system 1. Excellent water absorbabilityexchanging efficiency reaches 75%;2. Super fire-retardantSafe and reliable3. Mildew-proof, clean & healthy.Structure ofHeat exchangerReturning air of indoorExhaust airSuction of outdoor airCooled fresh air introduced inCompared to traditional way of ventilation, Fresh air processor reduces 28% of energy consumption!
21Part Ⅳ Digital scroll VS Inverter Comparing itemsDigital scrollInverterCapabilityadjustmentSEERElectromagnetic interferenceCan be omittedSever disturbance, expensive electromagnetic-proof apparatus must be installed;Capacity ShiftShift to 100% capability immediatelyMust have procedure of frequency conversionBy-pass of refrigerantNo needHave to installCooling CapacityDigital Multi UnitInverter UnitCapacity DemandedDigital onlyCommon Inverter comp.Digital & common parallel connection
22SummaryWMV 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.