Catalogue
RLC-PRC006M-EN 11
Application Considerations
Typical Unit Installation
Outdoor HVAC equipment must be located to minimize noise and vibration transmission to the
occupied spaces of the building structure it serves. If the equipment must be located in close
proximity to a building, it could be placed next to an unoccupied space such as a storage room,
mechanical room, etc. It is not recommended to locate the equipment near occupied, sound
sensitive areas of the building or near windows. Locating the equipment away from structures will
also prevent sound reflection, which can increase levels at property lines, or other sensitive points.
When physically isolating the unit from structures, it is a good idea to not use rigid supports, and
to eliminate any metal-to-metal or hard material contact, when possible.This includes replacing
spring or metal weave isolation with elastomeric isolators. Figure A4 illustrates isolation
recommendations for the RTAC.
For chiller sound ratings, installation tips and considerations on chiller location, pipe isolation, etc.,
refer to theTrane Air-Cooled Series R Chillers Sound Data and Application Guide for Noise
Sensitive Installations.
System Options - Ice Storage
Trane air-cooled Series R Chillers are well suited for ice production. An air-cooled machine typically
switches to ice production at night.Two things happen under this assumption. First, the leaving
brine temperature from the evaporator is lowered to around 22 to 24°F (-5.5 to -4.4°C). Second, the
ambient temperature has typically dropped about 15 to 20°F (8.3 to 11°C) from the peak daytime
ambient.This effectively places a lift on the compressors that is similar to daytime running
conditions.The chiller can operate in lower ambient at night and successfully produce ice to
supplement the next day's cooling demands.
The Model RTAC produces ice by supplying ice storage tanks with a constant supply of glycol
solution. Air-cooled chillers selected for these lower leaving fluid temperatures are also selected
for efficient production of chilled fluid at nominal comfort cooling conditions.The ability ofTrane
chillers to serve “double duty” in ice production and comfort cooling greatly reduces the capital
cost of ice storage systems.
When cooling is required, ice chilled glycol is pumped from the ice storage tanks directly to the
cooling coils. No expensive heat exchanger is required.The glycol loop is a sealed system,
eliminating expensive annual chemical treatment costs.The air-cooled chiller is also available for
comfort cooling duty at nominal cooling conditions and efficiencies.The modular concept of glycol
ice storage systems and the proven simplicity ofTraneTracer controllers allow the successful blend
of reliability and energy saving performance in any ice storage application.
The ice storage system is operated in six different modes: each optimized for the utility cost of the
hour.
1. Provide comfort cooling with chiller
2. Provide comfort cooling with ice
3. Provide comfort cooling with ice and chiller
4. Freeze ice storage
5. Freeze ice storage when comfort cooling is required
6. Off
Tracer optimization software controls operation of the required equipment and accessories to
easily transition from one mode of operation to another. For example:
Even with ice storage systems there are numerous hours when ice is neither produced or
consumed, but saved. In this mode the chiller is the sole source of cooling. For example, to cool
the building after all ice is produced but before high electrical demand charges take effect,Tracer
sets the air-cooled chiller leaving fluid setpoint to its most efficient setting and starts the chiller,
chiller pump, and load pump.