Geary Engineering, Inc. provided the mechanical and electrical engineering for the replacement of the HVAC systems and lighting improvements for the First Presbyterian Church in Lincoln, NE. The project began as an evaluation of the existing HVAC systems. Evaluations of the existing systems resulted in recommendations to replace the old steam heating system with a closed loop heat pump system. A geothermal heat pump system was also evaluated but was deemed too expensive. Energy calculations indicated a payback period of about 12 years based on the energy savings of the closed loop heat pump system. The recommendations presented to the Building Committee were accepted and Geary Engineering, Inc. was selected to complete the engineering design for the new HVAC and lighting systems.
The existing boilers, steam radiators, air handling units, condensing units and steam piping were removed. The new HVAC equipment was designed to go into the spaces vacated by the existing equipment. The entire construction project was completed while the building was occupied.
The closed loop heat pump system was designed to provide heating and cooling for the education and office areas. The original sanctuary is heated by new hot water radiators and cooled by the existing DX fan coil units. Unit ventilator type heat pumps were used in some locations where ceiling access was not possible. Vertical heat pumps were used to replace existing air handling units.
The pneumatic control system was deemed obsolete and was replaced with a new DDC control system. All of the circulation pumps, boilers, fluid cooler, and heat pumps are connected to the new control system along with all of the mechanical equipment in the existing church. The church personnel will have control over all systems within the church from a workstation located in the first floor office. The control system also allows for control from a remote Internet site.
The lighting systems throughout the entire church, except for the sanctuary, were upgraded with energy efficient lighting. The lighting levels were increased but the overall energy use was cut in half with the new lighting systems.