The key in selecting the most efficient HVAC system when using an integrated project delivery (IPD) approach is taking full advantage of all team members’ expertise early in the project to evaluate first cost, energy cost and operating and maintenance (O&M) costs.
Evaluating each of these costs should include areas not normally considered in selecting system types. Facilities professionals should start with a full IPD team “blue sky” session involving the owner, engineer, architect and construction manager early in the project and put all possible system types on a board.
There are no bad or wrong ideas; team members should allow the process to vet them out. For example, a site may be limited for geothermal. In that case, the team should consider a combination of system types, such as geothermal and DX dedicated outdoor systems to address the limitations. All team members should be allowed to provide pros and cons of each system. The session should finish with a list of system types for further evaluation.
The engineer and architect then develop pricing narratives for each system, including factors that affect the complete cost picture: mechanical room square footage cost, building floor-to-floor-heights, water usage, electrical cost for central vs. distributed HVAC system, full-time equivalent (FTE) staff cost required for each system, and preventive maintenance cost. The engineer provides an energy model analysis of each system. The construction manager enlists subcontractors to provide more detailed pricing input, and the construction manager utilizes a database to provide detailed O&M cost. The owner provides input on FTE staffing costs for any staffing requirements that are different for each system.
After all the cost data are in place, the team should conduct a life-cycle cost analysis (LCCA) based on the hospital’s specified time frame. Each system is ranked according to LCCA, and the entire IPD team provides input for the hospital to make the final decision on system selection.