Healthcare

Healthcare facilities consume energy in several key areas. These include heating, ventilation, and air conditioning (HVAC), which often accounts for the largest portion. Lighting, both interior and exterior, is a substantial user of electricity. Other significant areas of consumption are power loads from medical equipment, kitchen appliances, and other miscellaneous plug loads, plus domestic hot water. The specific proportions vary between facility types (e.g., hospitals vs. outpatient clinics) and geographic regions, but these categories are consistently the major energy consumers.

Existing building commissioning (EBCx) is a systematic process of identifying and correcting operational issues to improve energy performance and overall building function. It focuses on optimizing the existing systems and equipment through adjustments, repairs, and upgrades. EBCx typically involves a detailed investigation of building systems and often reveals inefficiencies such as improperly set controls, faulty sensors, and equipment operating outside of its design specifications. By addressing these issues EBCx can achieve energy savings with lower costs compared to full-scale equipment replacements. This process often precedes more extensive retrofit projects.

Lighting retrofits can significantly reduce energy usage. Direct replacement is a common approach, which involves swapping out existing lamps and fixtures with more energy-efficient options. This frequently includes replacing incandescent and fluorescent lamps with LEDs, as well as swapping out metal halide exterior lighting with LEDs. Designed retrofits are more comprehensive and might involve changing the entire lighting design of a space. This would include adding or reducing the number of fixtures, adjusting lighting intensity, utilizing daylighting, and implementing controls like occupancy sensors and photosensors to ensure lights are used only when needed. The goal is to achieve optimal lighting for the healthcare environment while minimizing energy waste.

Reducing supplemental loads goes beyond just HVAC and lighting. It involves focusing on equipment and systems that aren't directly related to patient care. One strategy is to simply ensure equipment is turned off when not in use and replacing old equipment with Energy Star certified models. This would involve everything from computers and vending machines to cafeteria equipment. Implementing energy awareness programs and replacing transformers with more efficient models are also useful strategies. Addressing the energy consumption of data centers in hospitals, which are significant users, is another way to reduce supplemental loads.

Improving the building envelope refers to minimizing heat transfer through the building's walls, windows, and roof. Key strategies for achieving this include sealing air leaks by addressing infiltration issues and improving the building's air barrier. Enhancing the thermal insulation of the roof and walls to meet current energy codes is critical, and upgrading windows and doors with low-e, double- or triple-paned options can also reduce energy consumption. These upgrades improve thermal performance, reduce reliance on heating and cooling systems, and contribute to overall energy efficiency.

HVAC systems are the biggest energy consumers in most healthcare facilities. This is due to the strict requirements for ventilation, temperature, and humidity control that are needed in a safe healthcare environment. Strategies to improve efficiency include adding or improving economizers to enable free cooling, optimizing air distribution, and implementing demand control ventilation (DCV). Further improvements can be achieved by right-sizing fans and pumps, adding variable speed drives (VSDs), and using heat recovery systems to capture waste heat from exhaust streams. These improvements not only reduce energy consumption but can also improve the operation and performance of the HVAC systems.

Improving heating and cooling involves looking at both central plant and local options. In central heating systems, strategies include replacing old boilers with high-efficiency condensing boilers or modular units, optimizing controls, and recovering heat from exhaust. For central cooling, options include optimizing chiller sequencing, ensuring pumps and chillers are the correct size, and adding water-side economizers. Using variable speed drives on pumps, chillers, and fans can also achieve savings. Consider alternatives to traditional systems such as Variable Refrigerant Flow (VRF) or using chilled beam heating. When it comes to domestic hot water, the addition of heat pumps or solar heating can provide energy savings.

Measurement and verification (M&V) is the process of quantifying and verifying the energy savings achieved through energy efficiency projects. It involves creating a baseline measurement of energy consumption before the implementation of any retrofit, and then using post-retrofit data to calculate the amount of energy saved, ensuring savings are actually realized and that systems are functioning as intended. M&V is important for accountability, ensuring return on investment, and for ongoing building optimization. It allows facilities to understand the true impact of energy-saving measures and refine them over time, as well as providing justification for further improvements.