How much energy does the ECM and dynamic controls sequence save?
Quite a bit. This is described on pages E1 to E4 in the Engineered Comfort catalog. The basic answer is that you can run anywhere from 2 to 12 Engineered Comfort units for the price of one 3-speed ac induction or PSC motor with a 2 position on/off valve. Our experience indicates payback periods for the extra money spent on the unit range from 6 to 36 months depending on model, local utility rates and sizing of the units. Of course, this depends on energy pricing, run times and unit mixes on the job, but they are not going to vary much. The additional price for the ECM motor and controls is about $300 in the United States. When making comparisons to other products, be sure to compare units that match quality and performance. Comparing a basic unit with no room control capabilities can yield larger differences. Please recognize that these savings do not include the reduced chiller costs because of greater delta T, the reduced pumping costs, nor the reduced heat loads due to lower delta T on the curtain wall.
Product: Fan Coils with Dynamic Fan Volume Control
Subject: Fan Coils Units
Source: Nailor Product Bulletin, May 15, 2007