What Factors to Consider When Evaluating a Turntide Retrofit

Just because we can retrofit the RTU, doesn't mean we should. Your client's utility rate, operating hours, climate, equipment size and control method in addition to available rebates will have a significant impact on determining the cost effectiveness of a Turntide motor retrofit. As a general rule of thumb, factors that result in better simple paybacks on Turntide retrofit projects include:

  • Motors of 3 horsepower or above (often found in RTUs 10 Tons and above).

  • Motor with high annual run hours.

  • Motors located within regions with higher utility rates such as the northeast, mid-Atlantic or northwest.  Incidently, these regions with higher rates also have better utility incentives.

  • Motors in RTUs that run in ON mode versus AUTO mode.

  • Motors that are not already connected to variable speed drives.

A number of resources to help quantify energy savings for a Turntide motor retrofit have been provided in our Engineering section. For a snap shot of annual energy savings, costs and simple paybacks by motor size, the table below uses national averages based on two run hour scenarios. This table is also downloadable in excel format here.

Turntide Smart Motor System vs. Standard Induction Motor in RTU Applications

Turntide Smart Motor System includes a motor and a controller.  The Turntide motor is a high rotor pole switched reluctance style motor.  When replacing standard induction motors in RTU applications, savings are achieved through a combination of Turntide motors being more efficient and the ability of Turntide motors to vary speed based on the operating mode of the RTU.  Turntide motors maintain a constant efficiency value regardless of the speed.  A summary of annual savings is provided in the table below for different motor sizes.  Annual energy savings and typical simple paybacks are presented for two operating hour conditions.  4,100 occupied hours represents a typical office or retail schedule.  7,500 occupied hours represents a 6 day, 24 hour schedule.  The installed cost for a typical Turntide retrofit is presented based on current list pricing for the Turntide's Smart Motor System plus estimated labor rates of $125 per hour at 4 hours per motor install.  Simple paybacks are NOT inclusive of any utility rebates which can significantly lower project cost.  The availability and value of rebates in addition to energy cost savings will vary by utility.

Savings Graph RTU.jpg