Though the intent of RCx was to identify and implement low-cost, short-payback energy conservation measures, the GBA team discovered significant problems early in its investigations and discussions with building staff. Air-handling units would often shut down in response to low-temperature safety switches; humidifiers would behave erratically in response to pressure changes; and the steam pressure-reducing valves (PRVs) required constant maintenance. The building exhibited extreme negative pressures, leading to elevator shutdowns and curtain wall frosting. The building staff believed system capacity must be inadequate.
- Through metering, data analysis, and on-site investigations, the engineers identified multiple problems that were limiting system capacity. Holistic solutions were devised to regain capacity and save energy without large expenditures.
- Problems related to configuration of the AHUs and their temperature controls were corrected to eliminate inappropriate tripping and restore functionality of the heat recovery system, as well as solving humidification issues.
- Steam valve failures and PRV setup errors were fixed so the steam systems could function properly, recapturing “lost” capacity.
- RCx produced verified annual savings of 88,000 therms of natural gas and greatly improved HVAC system stability. Verified annual savings of $106,000 per year were achieved in Phase 1 alone, with further potential savings identified in Phase II.
