Experimental study was conducted onimproving air-conditioners' energy efficiencyusing hydroponic roof plants. The air-coolingeffect caused by the solar-shading andtranspiration of hydroponic-cultivated sweatpotato was measured. Using the measured data,it is estimated that how much the energyefficiency of an air-conditioner can be improvedif the cooled air is introduced into the outdoorunit of air-conditioners. The measured airtemperatures and cooling loads were used tocalculate the energy consumption of theair-conditioner.

Sales data shows that the use of air-to-air heatpumps in New Zealand houses is rapidlyincreasing. This rapid uptake will lead to newenergy and peak power demands on theelectricity supply system. Recent monitoringwork lias found solid fuel burners provided 56%of home heating energy while only 24% waselectricity. Heat puinps are therefore inainlydisplacing non-electric heating, and this mustultimately require additional electricitygeneration, transmission and distributioninfrastructure. Patterns of use will be critical tothe long-term impact.

According to the definition, passive houses inEurope meet a target energy demand for heatingof less than 15 kWh per square meter and peryear. This low level for the heating demand isbased on heating by a small post-heater in thehygienic ventilation system at 52 C maximum,while the ventilation system can be dimensionedpurely for ventilation purposes. In theory thusthe installed heating power is less thanapproximately 10 watts/m2.But what happens in practice?

A new innovative design concept for the indoorair conditioning systems is proposed. Thisconcept uses passive control and modularly airdiffusion devices and aims complying with boththernial conifort and energy efficiencyobjectives. Passive control aspect is studiedthrough the comparison between a circularreference jet and a lobed jet having the sameexit area and initial flow rate. It is shown that across-shaped lobed orifice allows a consequentincrease of the entrainment within a large rageof initial Reynolds numbers. Moreover the jet'sthrow is conserved despite its strong initialinduction.

Energy consumed in the Canadian residential sector for space cooling has more than doubled from 1990 to 2002. Cooling requirements, expressed by cooling degree-days have also increased. In parallel, there has also been a noticeable increase in the penetration rate of airconditioning systems: almost 45 percent of households were equipped with some type of air-conditioning system in 2003. A comprehensive ventilation approach requires not only air exchange but also indoor liuinidity control.

Realistic knowledge of window-opening andfans use behaviour is needed, for the thermalsimulation of naturally ventilated buildings. Ifcontrols such us windows and fans wereefective and easy to use, thermal discomfortcould be largely avoided. In practice theremay be constraints that hinder the use of suchcontrols. In uny thermul simulation theseconstraints need numerical values. In thispaper, we explore the nature and extent ofsome of the constraints operating on the use ofwindows and fans, making numericalestimates of their magnitudes from extensivefield databases.

People who become too warm or too cool willadjust their clothing or reset building controls(windows, blinds, fans, thermostats) with theainz of restoring comfort or reducingdiscomfort, if they are free to do so. However,the trigger-temperatures for warm and colddiscomfort depend on (among other things)the clothing and the ,fan setting. The trigger temperaturesdiffer from person to person andfrom time to time. If several controls areavailable, people will first use those that areuser-friendly, effective and withoutundesirable consequences.

This paper describes some qf the thinking behind the thermal comfort provisions of the new European Standard EN1 525 1 (CEN:2007) for free-running buildings. This standard deals with all aspects on the indoor environment. The paper will presentthe evidence on which its provisions fortemperature in naturally ventilated buildingsin summer is based. It will discuss theadvantages they present jbr those concernedto design buildings which will minimise theuse of energy.

A survey of air conditioner temperaturesettings and clothing insulation was carried outfor university student rooms in June-Octoberduring daytime on weekdays in Osaka, Japan.The results are as follows. 1) Forair-conditioners that were turned on, thetemperature setting was 26-28C in 8 1.1 % ofcases. 2) Almost all respondents wore longtrousers and T-shirts, or that ensemble plus aninner shirt (78.9%). 3) Temperature settingsand thermal sensations differed by building. 4)Effects of soclts on thermal sensation wererecognized.

An investigation was performed in a middle-corridor-type elementary school in Tolcyo, Japan, equipped with an air-conditioning system for cooling.Temperatures and C02 concentrations weremeasured in classrooms, corridors and outdoors.Visual inspections were made on opened andclosed conditions of windows, doors andcurtains, and pupil numbers in classroomsduring each lesson hour. Pupils' and teachers'thermal environment evaluations andenvironmental control behaviors were obtainedfrom questionnaires.