Trane has enhanced its Optimus™ helical rotary water-cooled chiller with the Trane Adaptive Frequency™ drive (AFD). The AFD adjusts motor speed based on demand to reduce energy consumption. The Optimus chillers have cooling capacities ranging from 150 to 430 tons, making these economical cooling solutions for most facilities, including high occupancy schools, hospitals, and hotels. The chillers deliver up to 39% better energy efficiency than the ASHRAE 90.1 standard requires. And Trane Tracer™ controls allow facility managers to regulate system performance for increased efficiency.
The Optimus chiller can control water temperature variance within 0.5°F (0.3°C). This level of precision enables the Optimus chillers to manage industrial or low temperature process cooling and humidity in critical applications. The chiller can produce temperatures as low as 10°F (-12°C) for quick freezing applications, like ice rinks. When operating in heat-recovery mode, the Optimus chiller generates condenser water temperatures as high as 114°F (45.6°C), which can reheat air at variable air volume (VAV) boxes, preheat air for air handlers, and be used for snow melting processes.
Designed for easy installation, the Optimus chiller can be delivered through standard 72″x80″ double doors. The chiller’s bolt-together construction allows it to fit through even smaller entryways.
The direct-drive compressor used in the Optimus chiller is designed with few moving parts to reduce maintenance needs and failure risks. Under normal operating conditions, periodic tube cleaning and an annual oil check are the only manufacturer-recommended maintenance guidelines. In addition, the evaporator is designed to deliver high efficiencies using less refrigerant, which can help facilities attain LEED certification.
Meanwhile, Trane has introduced a tool to help facility managers and other specifiers chiller purchasing decisions. The Trane myPLV™ calculator is a free, manufacturer-agnostic tool that helps users estimate chiller energy usage based on project specific operating conditions.
Currently, the industry most often uses the Air-Conditioning, Heating and Refrigeration Institute (AHRI) Integrated Part Load Value (IPLV) to estimate future chiller performance. The IPLV is calculated using four operating points and weighting factors to estimate the percentage of time a single chiller, following an average load profile, will operate at various loads at a given set of entering-condenser water temperatures.
In addition to the part-load assumptions, the IPLV calculation uses the weighted national averages of various factors—including weather data from 29 U.S. cities and building data based on a Department of Energy study. Because the IPLV calculations are based on weighted averages for various buildings and climate zones, they cannot be applied to specific building types or locations.
“The AHRI IPLV metric was not intended to predict the annualized energy consumption of a chiller in specific applications or operating conditions but for the lack of a simple and accurate tool, the industry has been using it to do just that,” says Brian Fiegen, leader of Trane applications engineering group. “The problem is that a chiller in a hot and humid climate will operate differently than one in a cooler or drier climate, and the operation of a hospital is very different from an education or commercial facility.”