BCHP design for dual phase medical complex

Comprehensive value engineering conducted for a Midwest (USA) developer client focused upon their architect/engineer proposals for a nominal 100,000 m2 medical facility comprising under Phase I, two 12 storey medical office towers and adjacent six (6) storey hospital. Clientʹs architect-engineers had originally proposed constructing separate central heating and cooling plants for each of their (i.e., originally designed) Phase I buildings. Phase I plant layout and interim study results demonstrated significant building space and annual owning savings over conventionally designed individual (i.e., in situ) building heating and cooling plant and incorporated gas and steam turbine driven chillers and integrated gas turbine driven synchronous generator resulting in an estimated 2.6 year simple payback. However, subsequent client Phase II project scope expansion undertaken prior to commencing above referenced Phase I BCHP plant construction required major design changes. The subsequent Phase II redesign resulted in the elimination of higher cost heat recovery steam generator which was replaced with a low cost novel hybrid steam generator utilizing a non-toxic, hot-oil energy recovery system; replacement of costly condensing steam turbine with a less expensive combination serial back pressure steam turbine and indirect single stage absorption chiller bottoming cycle; the later sized for the additional Phase II new office tower subsequently required by client all without exceeding Phase I project budgetary criteria.