16 Evaporative Air-Conditioning: Applicationsfor Environmentally Friendly Cooling indoor units are available for US$40 and up; however, the largest and most expensive units sell for more than US$1,200. The investment cost for a direct-indirect system is roughly double that for a direct EAC unit (and in fact approaches the level as VAC). However, the direct-indirect EAC's power consumption is only about 25 percent higher than direct EAC on an annual basis, and the total cost of electricity and maintenance for indirect-direct EAC systems amounts to only about 50 percent of that of conventional VACs of compa- rable performance. Investment Costs Figure 3.1 compares typical total investment costs of EAC and VAC systems for different room sizes (20, 60 and lOOm 2 ) for the United States. In all cases EAC is the cheaper option. Figure 3.1. Typical Investment Costsfor Evaporative Air-Conditioning in the United States 2,500 - , 2,000- - 1,500 _ E 1,000 , 500- 20 EAC 20 AC 60 EAC 60 AC 100 EAC 100 AC Room size in sq m for EAC and AC ES Installation cost Cost cooler Source: R. Foster. It is striking that although the cost of EAC coolers in the United States is low, the cost of installation is relatively high, because of the labor involved in placing the cooler, connecting it to water and electric power sources, and providing a drain for the flush water. The same has been done for India in Figure 3.2. Here the difference between EAC and VAC is much more pronounced because EAC units are made by small wayside industries at very low cost, whereas VAC units are either imported or made by large, inefficient industries at much higher cost. The cost of installation in India is low because labor is cheap. These typical investment costs for India and the United States illustrate that the relative economic merits of EAC are more pronounced in devel- oping countries than in the industrialized world. Life-Cycle Costs The life-cycle and operational costs have also been analyzed for these two countries, as depicted in Fig- ures 3.3 and Figure 3.4. Economics 17 Figure 3.2. Typical Investment Costs for Evaporative Air-Conditioning in India 1,000- Cei- 800 600 - i 400 - 200- 0 20 EAC 20 AC 60 EAC 60 AC 100 EAC 100AC Room size in sq m for EAC and AC Installation cost Cost cooler Source: R. Foster. Figure 3.3. Typical Life-Cycle Costs: Evaporative Air-Conditioning versus Air-Conditioningfor the United States 6,000 - ,5,000 m) 4,000 8 3,000 2,000 1,000 0 20 EAC 20 AC 60 EAC 60 AC 100 EAC 100 AC Room size in sq m for EAC and AC * Depreciation 2 Energy n Water D Interest Maintenance Source: R. Foster. 18 Evaporative Air-Conditioning: Applicationsfor Environmentally Friendly Cooling Figure 3.4. Typical Life-Cycle Costs: Evaporative Air-Conditioning versus Air-Conditioningfor India 6,000 - -_ rA 5,000- 4,000 8 3,000 2,000 - 1,000 0- , , 20 EAC 20 AC 60 EAC 60 AC 100 EAC 100 AC Room size in sq m for EAC and AC * Depreciation E Energy n Water D: Interest Maintenance Source: R. Foster. For the calculation of the operational costs it was assumed in all cases that the maintenance is done by a hired professional, which explains the rather high annual maintenance cost for EAC in the United States. In reality, however, many EAC owners do their own maintenance because it is easy and saves money. In developing countries where labor is cheap, maintenance is generally done by professionals. In India, for example, it is common for owners of EAC units to have a maintenance contract with an EAC dealer. Market Situation At least 20 million residential EAC units are in operation worldwide. Of these, some 8 to 10 million are in India, and more than 4 million are in the United States. Other significant markets also exist in Australia, South Africa, Pakistan, and Saudi Arabia. EAC also has significant market potential in many other areas of the world (e.g., in the Sahel); yet in most of these areas, EAC technology is unknown. A significant reason why EAC units are not in operation in more areas around the world is that half or more of the world's population lives in coastal regions, or within 100 kilometers of coasts, and these areas are typically humid and hence generally not the most favorable sites for EAC units. In contrast, the most favorable climatic conditions for using EAC are in dry and hot desert regions, and these are com- paratively sparsely populated. Population differences notwithstanding, sufficient populations live in dry and hot regions to consti- tute meaningful markets for EACs. In the United States, for example the current sales of direct EACs are more than US$150 million per year. Moreover, the recent growth of the U.S. EAC market has been signifi- cant, with annual increases of 10 percent reported by manufacturers. California, which traditionally has used VAC, represents one of the world's fastest-growing EAC markets. The California Energy Commission (CEC), noting the 50 to 80 percent energy savings pos- sible with EAC (as opposed to VAC) technologies statewide, adopted energy credits for EAC as part of the Title 24 code compliance program in January 1993. Inclusion of EAC in the Title 24 program facili- tates significant prospective growth of the industry in California. The CEC is also promoting an EAC Economics 19 commercialization program that seeks to accelerate adoption of EAC to maximize its energy saving, environmental, and economic development potentials. Several California utilities are promoting EAC for commercial and residential applications as well. Pacific Gas and Electric (PG&E) offers rebates for commercial use of evaporative cooling equipment. Under the utility's customized program, hybrid and two-stage EACs can receive a US$200/kW reduc- tion as replacements for VAC technologies. PG&E also offers a line-item rebate for the installation of commercial evaporative cooling equipment at US$80 per ton displaced of VAC for new construction as part of a "Retrofit Express" program. Locally in California, the Sacramento Municipal Utility District (SMUD) has a new construction rebate program that provides rebates to EAC in the commercial sector based on calculated energy savings com- pared with conventional cooling. In late 1992 Southern California Edison began offering US$100 rebates for installation of residential EAC (direct and indirect-direct) in their service territory. The company has promoted these rebates actively in desert locations, offering an incentive of US$125 for replacement of residential VAC units with EAC equipment. Southern California Edison also provides and maintains EACs at no cost to qualifying low-income residents in their service area. On the commercial front, the company is interested in energy conservation in the retrofit market and offers rebates at US$75 per ton for direct EAC and US$100 per ton for indirect-direct EAC for displaced tonnage of VAC (they use 1,250 cfm = 1 ton cooling). About 30 to 50 commercial installations are taking advantage of this program each year. The State of New Mexico is requiring the use of EAC (mainly indirect-direct systems) instead of VAC systems in new public schools and additions. New Mexico places about 100 new EAC applica- tions per year in schools. The Stratospheric Ozone Protection Division of the U.S. Environmental Protection Agency (EPA) has included EAC as an acceptable technology in the EPA's Significant New Alternatives Policy (SNAP) rulings on alternative refrigerants and technologies. This should further encourage the adoption of EAC technologies in the United States. Greenpeace and other environmental organizations are advocating EAC as an environmentally re- sponsible technology worldwide. This type of interest from environmental organizations should also further global market development. The greatest market development problem facing the EAC industry currently is the lack of a normal- ized test standard for performance ratings. Saudi Arabia and Australia have some limited general test standards. However, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards committees on EAC have submitted a proposed test standard for testing indirect evaporative air conditioning equipment adopted by ASHRAE in 1996. Similarly, a proposed ASHRAE test standard for direct EAC units should be adopted in 1998. When these standards are adopted, the industry worldwide will benefit from a proposed certification program for rating EACs based on the ASHRAE test standards by the Evaporative Cooling Institute. This certification program will provide design engineers worldwide with an independent performance-based test standard for rating EAC units. The EAC market should continue to grow worldwide as interest from utilities and countries in- creases in applying the technology as an energy conservation tool. Given advances with indirect and hybrid systems that widen the climatic range of application, the potential market penetration of this technology is large. Indeed, when coupled with desiccant technologies, EAC could displace VAC tech- nologies in many applications in the coming century. . Maintenance Source: R. Foster. 18 Evaporative Air-Conditioning: Applicationsfor Environmentally Friendly Cooling Figure 3 .4. Typical Life-Cycle Costs: Evaporative Air-Conditioning versus Air-Conditioningfor. touch (Figures 4. 3 and 4. 4). This arrangement eliminates most of the problems associated with aspen wood because rigid pads have the following advantages: 24 Evaporative Air-Conditioning: . is shown in Figure 4. 2 for Ciudad Juarez. Figure 4. 2. Psychrometric Processfor Direct Evaporative Cooling, Mexico 20.7 0 CDB for S.E.=85% a / / ~~~Direct Evaporative oa /4/ / i~~Coling Process