District Ambient Temperature Loop (ATL)

This standard applies to ambient temperature loop (ATL) distributed energy systems and related low-temperature distribution systems. Such systems can be integrated with multiple renewables such as solar thermal and solar photovoltaic. An ATL system is a closed loop piping system with central pumping that includes various heat sources and heat sinks to hold the loop fluid near the long-term average ambient air temperature. The sources/sinks can be passive (e.g., a ground loop, a body of water, sewer effluent) or active (e.g. a cooling tower) and further can include, opportunistic, or unique locally available waste or byproduct heat sources (e.g., data center, industrial process). The closed loop piping system typically controls or engages these sources/sinks to maintain the loop temperature to meet the seasonal requirements as well as specific building needs.