Comparing Maintenance Costs of Geothermal Heat Pump Systems with other HVAC211 Systems in Lincoln Public Schools: Repair, Service, and Corrective Actions

摘要

The Lincoln Public School District, in Lincoln, Nebraska, recently installed211u001evertical-bore geothermal heat pump systems in four, new, elementary schools. 211u001eBecause the district has consistent maintenance records and procedures, it was 211u001epossible to study repair, service and corrective maintenance requests for 20 211u001eschools in the district. Each school studied provides cooling to over 70% of its 211u001etotal floor area and uses one of the following heating and cooling systems: 211u001evertical-bore geothermal heat pumps (GHPs), air-cooled chiller with gas-fired hot 211u001ewater boiler (ACUGHWB), water-cooled chiller with gas-fired hot water boiler 211u001e(WCCYGHWB), or water-cooled chiller with gas-fired steam boiler (WCUGSB). 211u001ePreventative maintenance and capital renewal activities were not included in the 211u001eavailable database. GHP schools reported average total costs at 2.13 cents/ft(sup 211u001e2)-yr, followed by ACC/GHWB schools at 2.88 cents/ft(sup 2)-yr, WCC/GSB schools 211u001eat 3.73 cents/ft(sup 2)-yr, and WCC/GHWB schools at 6.07 cents/ft(sup 2)-yr. 211u001eBecause of tax-exemptions on material purchases, a reliance on in-house labor, 211u001eand the absence of preventative maintenance records in the database, these costs 211u001eare lower than those reported in previous studies. A strong relationship (R(sup 211u001e2)=O.52) was found between costs examined and cooling system age: the newer the 211u001ecooling equipment, the less it costs to maintain.