Private School Boiler Plant Upgrade

March 1, 2024

In the pursuit of optimal energy utilization and improved operational efficiency, organizations often find themselves at a crossroads, contemplating strategic upgrades to their HVAC systems. This case study delves into a transformative project that centers around installing two new, high-efficiency boilers. This initiative was born from our client’s need to modernize their facility’s HVAC infrastructure and achieve significant energy savings.

Upgrade Boiler Plant for Education Building 

Design

Cox-Powell Corporation replaced the original Patterson Kelley Thermific 1580MBH 80% Efficient Heating Boiler, circa 1999, with (2) new Lochinvar FTXL 400MBH 98% Efficient Condensing Boilers to serve a Science Building on the campus. The Boiler Plant at this facility serves two purposes. Its primary purpose is to provide comfortable heating for the Science Building during the winter months. The Boiler Plant also operates the remainder of the year to provide reheat for dehumidification.  

The operating profile of the Boiler Plant leant itself to be a perfect fit for a Condensing Boiler System. In the winter months the Primary Loop was set to maintain 160F for Heating and the Bypass Loop must maintain 160F loop temperature to prevent flue gas condensation. During the summer months the Primary Loop is set to maintain 120F water temperature for Dehumidification. By installing the Condensing Boiler System, the heating system can now operate at a lower temperature in the summer for significant energy savings.   

Scope

First, we needed to prepare the Mechanical Room for the installation of the new Boilers. This involved isolating, disconnecting, and removing the existing boiler from site, complete with associated Boiler Pump, Hot Water Supply piping (HWS), Hot Water Return piping (HWR), Flue piping, and Bypass piping.  

The welded Natural Gas Piping also needed to be modified to make room for installation of the new equipment. We removed a section of the piping and installed a new malleable Mega-Press adapter and isolation valve. Installation of the Isolation Valve allowed natural gas to remain in service to the building during construction.  

Once demolition was complete, we installed one new concrete housekeeping pad in mechanical adjacent to the existing one vacated by removing existing boiler, complete with rebar reinforcement to Mech Room Floor. We then installed two (2) new Lochinvar FTX400N Condensing Boilers onto the Housekeeping pads in the Mechanical Room. 

The existing HW Heating loop was converted to a Primary Loop (Existing) utilizing the Existing Loop Pump, and Secondary Loop System to allow for proper cascade sequencing of the new boilers. This included installation of new Copper piping to connect remaining HW piping to a Primary Loop with outlets for Secondary Loop Piping to Boilers, complete with Boiler Circulation Pumps, Wye Strainers, Magnetic Filters, Check Valves, Isolation Ball Valves, and Boiler Drains. 

Once HW piping was filled and hydrotested for leaks, we Insulated HW piping affected by construction with l” ASJ faced fiberglass pipe insulation with PVC fitting covers and installed Pipe Designation and Direction of Flow Labels. 

New PVC flue Piping was then installed horizontally through exterior wall of the Mechanical Room, complete with support hardware and core drilled wall penetrations. Penetrations were sealed weathertight. Combustion air was piped to the new boilers from the existing flue that ran through the Second Floor to the Roof. The existing flue termination was converted to an intake via installation of Stainless Steel Wire Mesh to protect against ingress of debris and animals. Flue Gas Condensate was piped to the existing floor drain, complete with neutralization traps to mitigate acid content in the condensate water.  

New steel Natural Gas piping was installed from the new isolation valve in mechanical room to the new boilers. We pressure tested the new gas piping and performed inspection with Henrico County.  

We installed new conduit and cabling to connect the existing electrical power supply to new boilers and circulation pumps, complete with new Emergency Shutoff Switches for the boilers. We also installed new conduits to allow for integration of the new boilers into the existing BACnet Building Automation System. We coordinated with the School’s BAS contractor to save costs for subcontractors.  

Commissioning is the final step to bring the construction project to conclusion. We performed Factory Authorized startup on the Boiler System with the assistance of the School’s BAS Contractor and the Manufacturer’s Commissioning Agent. Once commissioning was completed, we placed the Boiler System into normal duty service, necessary final inspections with Henrico County were performed, staff training on proper use and care of the Boiler System was performed, and an Operation and Maintenance Manual was submitted to the school. 

Timeframe

The project was completed in four weeks during summer break for the school minimizing the impact on daily operations at this facility.

Impact

Installation of these new Boilers provided immediate energy savings for the school. Trending the operating profile of the existing Boiler allowed for the reduction in Natural Gas input, nearly 50% energy savings off the top. Coupled with an 18% increase in efficiency, reduction in energy consumption, and a smarter operating profile during the summer months, the school may potentially realize energy savings of up to 60+%. 

Conclusion

Through meticulous planning and innovative solutions, this particular private school has modernized its facility and unlocked substantial operational efficiencies. The new high-efficiency condensing boilers, have not only elevated the overall performance of the HVAC system but have also delivered on the goal of reduced energy consumption.

The success of this project reinforces the value of forward-thinking approaches to facility management and is a compelling example of how targeted upgrades can yield tangible and long-lasting benefits.

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