Executive Summary. Final July Introduction

Transcription

1 Air conditioning products, ENTR Lot 6 Executive Summary Introduction This is the executive summary of the air conditioning component of the preparatory study ENTR Lot 6 Air Conditioning and Ventilation Systems, performed in the context of the Ecodesign Directive. This study has been carried out for the European Commission (DG ENTR). The consortium responsible for the study was composed by Armines (lead contractor), BRE (Buildings Research Establishment, UK) and VHK (Van Holsteijn en Kemna, Netherlands). Subcontractors for the air conditioning part were Armines and BRE. Scope The objective of air conditioning systems is to ensure a cooling function for comfort purposes in buildings. The energy related products within the scope of this study can be entire air conditioning systems that supply this function, or parts thereof. Cooling cycles that extract the heat directly from the air in a room are called air conditioners, on the basis of the name of the cold source type they use (indoor air). Alternatively, the heat extraction inside the building can be ensured by an intermediate chilled water loop. In that case, the heat is extracted from the indoor air thanks to terminal water to air units and the water loop temperature is maintained around 10 C by a chiller (a cooling cycle which cools liquids). Depending on the means used by the cooling cycle to release the heat outside, cooling cycles can be air cooled, evaporatively cooled, or water cooled. In the latter case, heat is then extracted from the water circuit by a heat rejection unit. Cooling cycles are mostly of the vapor compression type. A few chillers (2% of the chiller market in numbers) use the absorption principle and are mostly heated by gas. Most vapor compression units are electric but gas engine compression air conditioners are just entering the market. Terminal units and heat rejection units that consume energy are also included in the scope of the study. These products are not cooling cycles. Instead, they comprise heat exchangers, including a fan to move the air.

2 The Lot 6 scope can be summarized as the main energy using product types below. Definitions are given in task 7 of the report. Operating principles can be found in Task Air conditioners Package air conditioner [air to air > 12 kw 1, water to air, evaporatively cooled] Split and multi split air conditioners [air to air > 12 kw, water to air, evaporatively cooled] VRF (Variable Refrigerant flow) systems (a split system where the expansion of the refrigeration occurs in the indoor units and not in the outdoor unit) [air to air > 12 kw, water to air, evaporatively cooled] 2. Chillers for air conditioning applications [air to water, water to water, evaporativelycooled, condenserless] 3. Air conditioning condensing units 2 [air to water, water to water, evaporatively cooled] 4. Terminal units to extract heat from the space to be conditioned Fan coils 5. Heat rejection units means from the cooling system Dry coolers Evaporatively cooled liquid coolers Cooling towers Cooling products are said to be reversible when they can also ensure a heating function, in addition to their cooling function. The cooling function of air conditioners is assessed as their primary function. Their heating function is assessed as a secondary function, in order to provide a basis for comparison with its assessment as a primary function in the ENER Lot 21 preparatory study. The heating function of reversible chillers that falls under the scope of ENTR Lot 6 is not studied, since it is already covered in the ENER Lot 1 study. Both cooling and heating functions of terminal units are fully assessed. Specific renewable energy solutions with limited applicability are not included; these include earth pipes, or seawater cooling. The applicability of the other alternatives to standard cooling cycles as potential design options is discussed in Task 5. Control systems are not considered as ENTR Lot 6 products. However, they are of interest regarding the impact they can have on the energy consumption of air conditioning systems and products. Default system controls are considered to evaluate the energy consumption of air conditioning products in Task 4. Better control strategies for products are improvement options considered in Tasks 5 and 6 of the study. 1 Air to air air conditioners with a cooling output below 12 kw are already covered by the EC regulation 206/ It is the outdoor unit of Air to air air conditioners.

3 Key findings The quantitative assessments of the environmental impact of the products that compose air conditioning systems confirm that all the products included in the scope should be eligible for Ecodesign measures, all the more so since the stock of air conditioning products used for comfort applications is expanding at a significant rate. The installed stock of air conditioners might increase from around 95 GW in 2010 to around 130 GW in The installed stock of air conditioning chillers might increase from around 180 GW installed cooling capacity in 2010 to around 270 GW in 2025, of which 75% should be composed of pre 2020 products, on which future Ecodesign measures will exert an impact. With an average EER 3 of about 3, this corresponds roughly to 100 GW power drawn from the grid at peak time in the summer (about 1/8 of the total power generation capacity in Europe). The stock of condensing units used for air conditioning could not be evaluated as it is a new air conditioning product type. The stock of fan coils of 24 million units in 2010 is important but growing slowly (est. 25 million units in 2020). Heat rejection unit share decreased sharply the last decade due to the legionella desease, but it still represent about 20 % by capacity of the chiller market. The installed stock of ENTR Lot 6 air conditioning products is estimated to consume approximately 97 TWh in 2010; it should be noted that the electricity consumption related to the heating function of reversible chillers has not been included in this figure (it accounts for an additional estimated 15 TWh). The impact of condensing units is estimated to be still very low. There is also a relatively low contribution to electricity consumption from terminal units (2 TWh) and heat rejection units (1 TWh). Overall, electricity consumption during the use phase of air conditioning products constitutes the greatest contribution to environmental impacts. The second largest contribution to environmental impacts for cooling cycles is from refrigerant emissions to the atmosphere. These are mainly due to leakage in the use phase, faulty refrigerant management and partial recovery of the refrigerant fluids at the end of life. In order to assess the energy consumption and to maximize the improvement potential of air conditioners and chillers, a seasonal energy efficiency ratio (SEER) metrics has been adapted from the EN14825 standard. The study provides a set of coefficients that translate the typical use of the products to be used with the standard s method. As opposed to the EER (Energy Efficiency Ratio) that qualifies the efficiency of the unit at maximum cooling output under design conditions, the seasonal energy efficiency ratio (SEER) metrics is a weighted average of the energy efficiency ratio of the unit at different outdoor temperatures and cooling load ratios. It is thus a better indicator of the average energy efficiency, while the EER is a better indicator of the design efficiency (when maximum cooling output is required). 3 EER : Energy Efficiency Ratio ; ratio of the cooling output to the electric input measured under standard rating conditions.

4 Air conditioners and chillers have still a large potential for improvement if the best available technologies (BAT) are used. BAT for this group of products encompasses better individual components, such as EC motors for fans, larger heat exchangers, better part load control, and optimized part load designs. To maximize the potential benefits, the efficiency must be judged via a seasonal performance standard. However, full load performance should not be forgotten, because the externalities linked to the management of the peak demand may be important in some EU countries. Potential alternative refrigerants have been screened. Regarding air conditioners, there is no perfect alternative for split and VRF air conditioners. For chillers, refrigerant choice is larger, because there is no refrigerant fluid circulated inside the occupied rooms but chilled water. In both cases, the industry is now envisaging lower GWP (Global Warming Potential) refrigerant fluids, in anticipation of worldwide HFC (Hydrofluorocarbons) ban. Replacement solutions envisaged include refrigerants which are pure HFO (Hydrofluoroolefins) refrigerants (flammable, but already used in car air conditioners), or blends of HFO and HFC refrigerants (currently the preferred option). The improvement potential has been modelled and evaluated for air conditioning chillers and air to air air conditioners. The method that has been used for the analysis of the improvement design options of cooling generators is a mix between an engineering approach based on simplified models for energy performance and costs calculations, and a techno economic analysis of existing product ranges currently sold in the EU. The results show there is an important potential to raise the energy efficiency at least life cycle cost (LLCC) level, with 40 % lower energy consumption than for the median product sold today, and even more than 50 % for best available technologies. In terms of TEWI 4 however, the fall would be limited because of the increase in refrigerant charge (mass) and so in refrigerant emissions: a design with a 40 % lower energy consumption would result in CO 2 eq 5 emission between 15 % (decrease) and + 10 % (increase) for air conditioners, and around 20 % for chillers). The main reason for this large impact of direct CO 2 eq emissions is that the number of equivalent active hours of use per year for air conditioning is relatively low (600). For air conditioning products using refrigerants, it thus appears necessary to decrease the direct emissions of refrigerants in conjunction with the increase in efficiency. In that direction, the EC regulation 842/2006 (and revision) should help to decrease the direct emissions all along the product life, whatever the refrigerant fluid. Under the Ecodesign directive, it is also possible to lower refrigerant charge or to foster the use of alternative refrigerants with lower GWP than standard HFC refrigerants. These possible designs have been integrated into the analysis and the conclusion is that all lower GWP refrigerant fluid alternatives contribute to decrease the product CO 2 eq emissions at much lower levels than if only the electricity consumption is reduced. 4 Total Equivalent Warming Impact sum of direct CO 2 equivalent emissions through refrigerant dumped into the atmosphere and CO 2 equivalent emission due to the part of the electricity generation using fossil fuel 5 CO 2 eq emissions means equivalent CO 2 emissions. Different gases are compared to the CO 2 regarding their global warming potential; the CO 2 is the reference and has a global warming potential of 1. The global warming potential is an indicator of the relative radiative forcing a gas exerts in the earth atmosphere.

5 With very low relative impact as compared to the ones of chillers and air conditioners, the improvement potential of condensing units, terminal units and heat rejection was not evaluated. In addition, it has been concluded that optimizing terminal units and heat rejection units per se had little value when compared to the choice of an appropriate unit enabling to optimize the energy consumption of cooling generators. Based on the technical analysis of the improvement potential, policy scenarios are proposed, which define minimum seasonal energy efficiency ratios and minimum full load energy efficiency ratios for chillers and for air conditioners. Given its importance regarding the relative increases or decreases of CO 2 eq emissions, possible scenarios for refrigerant fluids are discussed. It is concluded that it is necessary to show high ambitions for the long term, in order for the market to shift to alternative refrigerants. For this purpose, it is proposed to take strong measures in 2019, comprising a ban of some of the refrigerants above a certain GWP, or where an ambitious TEWI threshold is exceeded, and to allow 10 % lower seasonal performance indexes for products charged with lower GWP refrigerants up to that date. Based on part load, full load and refrigerant proposed measures, the expected annual savings in electricity and equivalent CO 2 emissions are: TWh and 2.2 Mt CO 2 eq for air conditioning chillers, in TWh and 5.3 Mt CO 2 eq eq. for air to air air conditioners (including the heating function of reversible products), in 2025 As not optimized per se, no minimum performance requirement has been proposed for condensing units, terminal units and heat rejection units. In addition, sound power limitation, air emission limitations and possible solutions to favour the recycling efficiency for the products are proposed. Information requirements are also proposed, in order to help design engineers to improve the selection and sizing of Lot 6 products, when designing an air conditioning system for a specific building. These information requirements are proposed per product category, and comprise energy performance, in accordance with different temperature and load conditions; it should also be noted that the corresponding standardizing needs have been reported, in parallel. This should help to further decrease the energy consumption of these products in the field.

6 Tasks and reporting The structure and content of the Tasks follow the tender specifications and the MEEUP methodology 6. The reporting structure follows the Task structure. Task 1 classifies and defines the energy using products covered by this ENTR LOT 6 Air Conditioning and Ventilation Systems study, as well as their functionalities and performance parameters. Furthermore standards and existing legislation for the defined energy using products are investigated. Task 2 entails the economic and market analysis of the energy using products in the air conditioning systems. Furthermore, the task report supplies the necessary economic ingredients for subsequent tasks. The main focus in Task 3 is on user requirements. Relevant user parameters are an important input for the assessment of the environmental impact of a product during its use and end of life phase. Task 4 entails the assessment of average EU product(s) that have to be defined as representative product Base cases for the whole of the EU 27. In these Base Cases, most of the environmental and Life Cycle Cost analyses are constructed, for subsequent use throughout the rest of the study. The base cases are the point of reference for Task 6 (improvement potential) and Task 7 (impact analysis). Best available technologies (BAT) and Best not yet available technologies (BNAT) are analysed in Task 5. The environmental performance of BAT and BNAT both provide part of the input for the identification of the improvement potential analysed in Task 6. Task 6 analyses the Ecodesign improvement potential through identification of design options, their monetary consequences in terms of Life Cycle Costs (LCC) for the user, their economic and possible social impacts, and pinpointing the solution with the Least Life Cycle Costs (LLCC) and the BAT. Task 7 comprises the policy, scenario and impact analysis, based on all the preceding tasks. It looks at suitable policy means to achieve the potential. It draws up scenarios /2025, quantifying the improvements that can be achieved versus a Business as Usual scenario. Impacts on consumers and industry are also assessed. 6 Kemna, R. et al., Methodology for Ecodesign of Energy using Products (MEEuP), VHK for European Commission DG ENTR., Nov Available on line: business/ecodesign/methodology/index_en.htm