Shaping the Energy Efficiency in New Buildings - Building Energy ...

Australia mandates that central heating water piping located in an unconditionedspace must be thermally insulated to achieve fixed minimum R-values rangingfrom 0.2 (the hottest zone) to 0.6 (the coldest zone). Heating and coolingductwork and fittings must be sealed against air loss and achieve set minimumtotal R-values ranging from 0.4 (for fittings across all zones) to 1.5 (for heatingonlysystems or refrigerated cooling-only systems in the coldest zone) (BCA2007).Commercial building energy codes in both Canada and the United States provideminimum pipe insulation thickness and insulation conductivity for hot watersystems (MNECB 1997 and ASHRAE 90.1-2007). The United States requirescirculating service hot water piping in a residential house to be insulated to atleast R-2 (IECC 2006); for houses in Canada this value is R-1.5 (MNECH 1997).India requires piping for heating systems with a design operating temperature of60 o C or higher to have at least R-4 insulation and R-2 for heating systems with adesign operating temperature of less than 60 o C (ECBC 2007). South Korea requires a minimum insulation thickness of between 25 mm and 50mm, depending on the pipe diameter for hot water piping. For cold water pipes,the range is between 25 mm and 40 mm with the goal of preventing condensation.For boilers and other heat generation systems, the insulation thickness must bebetween 25 mm and 70 mm.Controls Canada requires service water heating systems with storage tanks in buildingsand houses to be equipped with automatic temperature controls and shutdown controls forany storage capacity over 100 liters (MNECB 1997 and MNECH 1997).Japan’s building energy codes promote the use of controls for water heating incommercial buildings (CCREUB 1999).Service water heating system controls in the United States commercial buildings includetemperature controls, temperature maintenance controls, outlet temperature controls, andcirculating pump controls (ASHRAE 90.1-2007). Residential building codes require that“automatic-circulating hot water system pumps or heat trace shall be arranged to beconveniently turned off automatically or manually when the hot water system is not inoperation.”Pools Canada, India and the United States have similar provisions on swimming pools,which cover pool heaters, time switchers and pool covers.Solar water heating India’s code requires the use of solar water heating in residentialfacilities, hotels, and hospitals with a centralized system to provide at least one fifth ofthe design capacity heating (ECBC 2007). South Korea has provisions for solar waterheating in BDCES 2008. Solar water heating should have active demand control tomaximize daytime consumption and reduce heat storage capacity, and an integratedcontrol system installed between the solar heating and auxiliary heat source (BDCES2008). Codes in Australia, Japan and the United States also provide exceptions to otherrequirements when solar water heating is used.Air pollution When installing a combustion-type heating or hot water supply system inresidential houses, the Japan residential standard encourages property owners to takemeasures to minimize contamination of the inside air (CCREUH 1999).51