1. Evaporative coolers as a substitute for air conditioning? Graham Palmer M.Eng (Sustainable Energy) RMIT IEST5011 Feb 2008

2. Air conditioning versus evaporative cooling Refrigerated - wall units, split systems, ducted Refrigerated - wall units, split systems, ducted Market dominated by wall hung splits sold by bulk stores Market dominated by wall hung splits sold by bulk stores Rapidly increasing a/c penetration – Australian sales of 800,000 units per annum (AGO 2006) Rapidly increasing a/c penetration – Australian sales of 800,000 units per annum (AGO 2006) Air conditioners have dropped in price and been aggressively marketed Air conditioners have dropped in price and been aggressively marketed COP of 2.0 to 4.1 – current MEPS require 2.75 COP of 2.0 to 4.1 – current MEPS require 2.75 A/C efficiency drops as temperature rises A/C efficiency drops as temperature rises Ducted Ducted Main market is now new homes Main market is now new homes Falling market share overall Falling market share overall COP of typically 14 - star rating doesnt apply, but would be 41! COP of typically 14 - star rating doesnt apply, but would be 41! Efficiency increases as temperature rises Efficiency increases as temperature rises Performance drops as humidity rises Performance drops as humidity rises Air conditioning Evaporativecoolers

3. Whats wrong with air conditioners? Top 10% of network capacity used 1% of the time Top 10% of network capacity used 1% of the time Problem mainly caused by residential air conditioning on hot days Problem mainly caused by residential air conditioning on hot days Cooling only represents small component (~2%) of residential greenhouse emissions but aggravates electricity supply policy debate Cooling only represents small component (~2%) of residential greenhouse emissions but aggravates electricity supply policy debate Authorities engaged in problem of keeping the lights on Authorities engaged in problem of keeping the lights on Demand growth out of control Demand growth out of control $13,000 per air conditioner potentially (Qld Minister for Energy 2004) $13,000 per air conditioner potentially (Qld Minister for Energy 2004) Requires additional peaking plant + transmission Requires additional peaking plant + transmission A/C cost $300-$500 per 1 kW of electrical power A/C cost $300-$500 per 1 kW of electrical power Estimated cost of $2,800 to provide an additional 1 kW of power (BCSE 2003) Estimated cost of $2,800 to provide an additional 1 kW of power (BCSE 2003) Yet same a/c may produce revenues of $12/annum Yet same a/c may produce revenues of $12/annum Householders without a/c are effectively subsidising those with a/c Householders without a/c are effectively subsidising those with a/c Source: Watt 2005

4. Evaporative coolers Principle dates back to ancient Egypt Principle dates back to ancient Egypt Use approx 1/5 to 1/4 of the energy where conditions are appropriate Use approx 1/5 to 1/4 of the energy where conditions are appropriate Third of the capital cost compared to ducted refrigerated air conditioning Third of the capital cost compared to ducted refrigerated air conditioning Whole house evap. similar to two splits Whole house evap. similar to two splits Consumers report very high satisfaction with coolers (Melbourne) – prefer evaporative to refrigerated regardless of costs Consumers report very high satisfaction with coolers (Melbourne) – prefer evaporative to refrigerated regardless of costs Typical cost $3500 - $4500 for whole house Typical cost $3500 - $4500 for whole house Water use an issue, but typically 10% rural Qld Water use an issue, but typically 10% rural Qld Relative performance improves with temperature for a given absolute humidity Relative performance improves with temperature for a given absolute humidity Ineffective on humid days, but ventilation improves comfort, particularly with ceiling fans Ineffective on humid days, but ventilation improves comfort, particularly with ceiling fans Source : http://www.brivis.com.au

5. Evaporative cooler penetration Maintaining market share in new homes in Vic. but declining for existing homes Maintaining market share in new homes in Vic. but declining for existing homes Australian sales approx. 55,000 units per annum compared to 800,000 refrigerated Australian sales approx. 55,000 units per annum compared to 800,000 refrigerated Market share 8% Market share 8% Main suppliers Bonaire, Breezair, Brivis Main suppliers Bonaire, Breezair, Brivis

6. Refrigerated wall splits getting cheaper because of reduction in manufacturing costs and strong Aussie dollar Refrigerated wall splits getting cheaper because of reduction in manufacturing costs and strong Aussie dollar Virtually all the marketing is by large Japanese and Korean manufacturers Virtually all the marketing is by large Japanese and Korean manufacturers Require in-home quotation and experienced staff Require in-home quotation and experienced staff Not suited to bulk store sales model Not suited to bulk store sales model Walk out with a box Walk out with a box Split systems easier to install and preferred by many tradesmen Split systems easier to install and preferred by many tradesmen No thermostat – doesnt match common expectations of operation No thermostat – doesnt match common expectations of operation Some experts in the a/c trade prefer refrigerated Some experts in the a/c trade prefer refrigerated Margins squeezed on evaps - tradesmen can charge full rate on splits Margins squeezed on evaps - tradesmen can charge full rate on splits Some old myths, stories and biases - damp, swamp etc.. Some old myths, stories and biases - damp, swamp etc.. Depending on location, there may be a couple of days a year when they are not effective Depending on location, there may be a couple of days a year when they are not effective Expectation of comfort changing, city higher than country – expect 22 o all year round Expectation of comfort changing, city higher than country – expect 22 o all year round Mostly Australian made, but manufacturers are now marketing refrigerated as well - has reduced possibility of industry wide promotion opportunities Mostly Australian made, but manufacturers are now marketing refrigerated as well - has reduced possibility of industry wide promotion opportunities Why arent evaporative coolers more popular?

7. Source : http://www.bom.gov.au/cgi-bin/climate/cgi_bin_scripts/clim_classification.cgi Blue lined areas have potential for evaporative cooling. Region around NSW central coast and Sydney is marginal.

8. Melbourne Hourly temperature and RH for 1/1/2000 to 31/12/2000 Ideal Good Marginal 0 51015202530354045 Temperature ( o C) Relative humidity (%) 20 80 100 60 40

9. Melbourne & Sydney Hourly temperature and RH for 1/1/2000 to 31/12/2000 Ideal Good Marginal 0 51015202530354045 Temperature ( o C) Relative humidity (%) 20 80 100 60 40 Ineffective

10. Overview Evaporative coolers offer excellent performance in many regions in Australia in terms of comfort and energy consumption Evaporative coolers offer excellent performance in many regions in Australia in terms of comfort and energy consumption Water an issue, but relatively minor and solvable Water an issue, but relatively minor and solvable Not suitable in tropical/semi-tropical regions Not suitable in tropical/semi-tropical regions Substantially better for greenhouse/peak demand Substantially better for greenhouse/peak demand But many factors work against evaporative coolers But many factors work against evaporative coolers Low hanging fruit from a greenhouse viewpoint Low hanging fruit from a greenhouse viewpoint Market share well below potential Market share well below potential Effective response to electricity network market failure Effective response to electricity network market failure

11. What should we do? Evaps substantially reduce capital expenditures compared to air conditioners – why not provide incentives to purchasers through electricity retailers or government agencies? Evaps substantially reduce capital expenditures compared to air conditioners – why not provide incentives to purchasers through electricity retailers or government agencies? Consumers not fully educated in choices, and the system works against effective information delivery – need govt. sponsored information Consumers not fully educated in choices, and the system works against effective information delivery – need govt. sponsored information Straightforward, accessible information Straightforward, accessible information Develop a simple measure of the performance of evaporative cooling for specific locations throughout Australia Develop a simple measure of the performance of evaporative cooling for specific locations throughout Australia Star rating Star rating Smart metering and demand management Smart metering and demand management Encourage efficient technologies, including indirect evaporative for humid conditions Encourage efficient technologies, including indirect evaporative for humid conditions

12. Ban air conditioning Make PV mandatory with A/C Current Australian political feasibility EasyImpossibleChallenging Highly effective Beneficial Irrelevant Medium term greenhouse reduction potential Lift MEPS New home building standards Encourage evaporative cooling Existing home building standards Time-of-day tariffs Remote demand control Overall increase in electricity price Preferred policy Less effective policy

13. Thank you