Technical article 1 min read Kyoto Mühendislik technical team
A chiller spends only a very small part of its life running at full capacity. Even so, selections are usually made by looking at full load efficiency.
The real operating profile
In a typical commercial building the chiller spends most of its running hours below half of its capacity. Full load occurs only on the few hottest days of the year and at certain hours of the day.
Seasonal efficiency values
Seasonal efficiency values, which reflect part load performance, weight the unit's efficiency at different load ratios and reduce it to a single number. Looking at this figure when comparing units is far more realistic than looking at full load efficiency.
How many units should there be?
Two or three smaller units run more efficiently at part load than one large one. And if one unit fails, the building is not left entirely without cooling. In healthcare buildings and data centres redundancy is mandatory in any case.
Sequencing control
The order in which multiple units start, and at what load ratio, must be set up correctly on the automation side. Wrong sequencing runs many units at low load and lowers efficiency.
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