The Multistack modular chiller system has gained increasing popularity, due to its compact footprint. Units are particularly popular in buildings located in high density urban environments, where mechanical room spaces may be constrained. Modules are designed to fit through a standard 36" door and load onto a standard capacity passenger elevator. Modules as small as 20 tons of capacity are meant to be coupled to provide overall plant capacity up to 1,200 tons.
Care needs to be exercised to provide sufficient water treatment for the condenser water loops, to prevent fouling of chiller heat exchangers. Due to the compact size of units, heat exchangers are more sensitive to fouling than a full-size centrifugal chiller. Due to the modular nature of the system, staging of compressors is performed by Multistack's native controller. The Multistack system employs a chiller water temperature reset strategy to accomodate part-load conditions. This strategy may not be conducive to applications requiring precise chilled water temperature control. We recommend careful evaluation of system volume, to prevent excessive compressor cycling. A buffer tank may be required.
Alternative manufacturers include Climacool and Arctic Chill.