St. Joseph’s High School

St. Joseph’s High School was looking for an energy efficient way to manage their heating and cooling for their gym and chapel. They had main three criteria to solve their HVAC requirements.

  1. The school needed to provide cooling to the entire school. Any additional equipment added to their current HVAC could potentially overload their electrical system, making cooling the entire school a challenge.
  2. Josephs wanted to be energy efficient and reduce their expenses.
  3. They had an older steam boiler for heating that was inefficient and expensive to run.

Controlled Air Inc. investigated multiple solutions including typical electrical VRF and a YANMAR VRF (GHP) gas powered heat pump system. Through analysis it was determined that the YANMAR VRF GHP would be the best solution for the school. The YANMAR VRF GHP would meet their requirements, by providing heating and cooling, reducing power demand, decreasing the need for the steam boiler, as well as being energy efficient. Since the Yanmar requires less electrical power to run the school would have the ability to add cooling throughout the school without overloading their electrical system. Additionally, the YANMAR system removed the need to use the steam boiler to heat the gym, reducing the need to run the boiler.

Controlled Air INC. installed four YANMAR 14-ton gas heat pumps which included two air handler units with variable air flow. Also included was the newest Johnson Controls FX-80 supervisory front end controller with a web based interface. The new system was 20% more efficient than  the electric cooling alternative and 50% more efficient than the current steam heating.


The YANMAR Variable Refrigerant Flow (VRF) natural gas heat pump (GHP) system provides a flexible way to efficiently heat and cool many different types of buildings. By using natural gas to power a YANMAR gas engine, YANMAR’s VRF system is able to reduce electrical costs by 90% and lower average operating costs by 30% over a standard electric system. By using world class Yanmar gas-engines to drive the system, these reversible air-source heat pumps can give low running costs, reduce CO2 emissions and use very little electricity. GHP is a well-established technology and Yanmar has been one of the leaders in this field for the last 30 years. By offering Air-to-air (VRF) and Air-to-water GHP systems, Yanmar can provide efficient and cost effective solutions for a wide range of cooling and heating applications.

These systems are ideal in many applications where cooling and heating might be necessary at the same time in different areas of a building such as offices, schools, hospitals, labs and mixed use facilities.

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St. Joseph’s High School
St. Joseph’s High School