24 week case study... During a 24 week case study, there was a savings of approximately 65-70%. How? A single speed pump was replaced by an Armstrong Tango (2 pumps) Design Envelope pump. These pumps offer Parallel Sensorless technology with increased turn down. It also has on board flow metering. This site will be getting a bit of a pump overhaul at a later date. #hvac #hydronricpump #chillerpump #boilerpump #hvacservice