11/9/2022 0 Comments Ashrae 90.1 2013 pdf free download![]() ![]() ![]() In these types of spaces, the cooling load decreases as the outdoor dry-bulb temperature decreases which reduces the need for cooling and limits the benefit of economizer cooling.ħ. Spaces where the cooling load is dominated by envelope loads. Systems that serve residential spaces where the system cooling capacity is less than 270,000 Btu/hr (22.5 tons, 79.1 kW).Ħ. the amount needed to preheat the peak service hot-water draw to 85F (29C).ĥ. ![]() 60 percent of the peak heat rejection load at design conditions, orī. Systems that include condenser heat recovery with a minimum capacity of:Ī. In all other buildings where more than 25 percent of the air is supplied to spaces that are designed to be humidified to a dew-point temperature above 35F (2C) to satisfy process needs.Ĥ. Hospital and ambulatory surgery centers where more than 75 percent of the air supplied by the system is delivered to spaces that are required to be humidified to a dew-point temperature above 35F (2C). Systems that require non-particulate air cleaning, such as ozone, based upon the requirements of Section 6.2.1 in ANSI/ASHRAE Standard 62.1.ģ. Individual fan-cooling units which have a cooling capacity less than 54,000 Btu/hr (4.5 tons, 16 kW).Ģ. The following exceptions, for comfort cooling applications, are paraphrased from Standard 90.1-2013:ġ. ![]() For distributed cooling systems, such as chilled-water fan coils or VRF, the Standard 90.1 User's Manual clarifies that the threshold applies to the individual fan coil or indoor VRF terminal, not to the total capacity of the central chiller plant or the outdoor VRF unit.Įconomizers are required for each cooling system that has a fan, however, there are a number of exceptions to this requirement. Examples of individual fan cooling units include air handlers, packaged rooftop units, water-source heat pumps, fan coils, and variable refrigerant flow (VRF) terminals. Put simply, an individual fan-cooling unit is a single cooling system that contains a fan. The standard uses the phrase individual fan-cooling unit to describe the type of system that should be evaluated to determine if an economizer is required. Before we dive in, let's start with a definition. Standard 90.1 also describes allowable economizer control types and corresponding high-limit shutoff setpoints for various climate zones. There are a number of exceptions to the economizer requirement (see sidebar p. Aįigure 1 shows a map of the United States with climate zones requiring economizers in gray and the climate zone not requiring economizers in red (1A). It does not suggest which type of economizer to use, however, the airside economizer must be capable of providing up to 100 percent of the design supply airflow as outdoor air for cooling.Ģ015 Trane, a business of Ingersoll Rand. The standard requires airside or waterside economizers for individual fan-cooling units greater than 54,000 Btu/hr (4.5 tons, 15.8 kW) for all climate zones except 1A and 1B (very hot-humid and very hot-dry, respectively) where the benefit of airside economizing would be limited. In this newsletter, we'll focus on airside economizer requirements in comfort cooling applications. Standard 90.1-2013 includes similar prescriptive requirements for both comfort cooling and computer room applications (see sidebar p. climate zones requiring economizers per ASHRAE Standard 90.1-2013 This EN reviews the economizer requirements of ASHRAE Standard 90.1-2013, Energy Standard for Buildings Except Low-Rise Residential Buildings, the newest version of the popular energy standard, with a focus on airside economizers.įigure 1. Previous ENs discussed the benefit and operation of an airside economizera device used to conserve mechanical cooling energy and reduce operating costs. Engineers Newsletterproviding insights for todays hvac system designerĪirside Economizers and ASHRAE Standard 90.1-2013 ![]()
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