Energy Efficiency In Hospitals
The Green Series - Article 2 Part 1
Photo by Ashes Sitoula on Unsplash
Introduction
A Green hospital is a healthcare facility designed to promote patient well being and support the healing process by integrating sustainable practices and efficient use of natural resources. Healthcare facilities day or night energy use are different from other buildings due to their functional characteristics, and contain complex systems including operating rooms, x-ray/scanner rooms, patient rooms, and various sterile areas. Heating, cooling and ventilation systems in these areas consume considerable energy. Energy conservation is a major objective in designing and operating green buildings.
Focus Areas For Green Hospital Design
Energy Saving Measures
a. Photovoltaic (Solar Energy): This renewable energy source reduces reliance on fossil fuels and lowers greenhouse gas emissions.
b. Solar Collectors: These systems improve energy efficiency by reducing the need for conventional water heating methods that consume electricity or gas.
c. Building Automation System (BAS): It integrates and controls various building technologies such as lighting, HVAC, and security thus significantly reduces energy consumption.
d. Absorber Chiller Unit: The absorber chiller uses the heat to provide cooling, effectively utilizing energy that would otherwise be lost.
e. Energy Recovery Systems: Energy recovery ventilators capture heat or coolness from exhaust air and transfer it to incoming fresh air, leading to substantial energy savings in ventilation.
f. Core Activated Concrete: Core activated concrete incorporates chilled water pipes within the building’s structural elements, such as ceilings or floors. This technique allows the building mass to absorb and store thermal energy, providing passive cooling and reducing the demand on mechanical air conditioning systems.
Lighting
Hospital design should prioritize maximizing natural daylight while carefully optimizing the use of artificial lighting to create a comfortable and energy-efficient environment. [2][3]
a. Daylighting approach not only reduces the reliance on electrical lighting during daytime hours but also enhances the overall ambiance and supports the health and recovery of patients.
b. Optimizing artificial lighting involves selecting appropriate lighting fixtures, controls, and placement to complement natural light, ensuring consistent illumination levels throughout the facility regardless of external conditions.
c. Effective lighting design in hospitals contributes to energy savings, reduces operational costs, and improves the well-being and productivity of both patients and healthcare staff.
d. Installation of sensors detect presence and automatically switch lights on or off. This reduces energy waste by ensuring lights are only used when spaces are occupied.
e. Recommended Lighting Levels for Hospitals: Different areas within a hospital require varying lighting intensities based on their specific functions.
(1) Patient Rooms: Moderate lighting levels.
(2) Operating Rooms: High-intensity, focused lighting.
(3) Emergency Rooms: Bright and adjustable lighting.
(4) Corridors and Waiting Areas: Adequate ambient lighting.
Climate Control Key Guidelines and Parameters
Maintaining strict climate controls in a hospital is critical for patient healing, infection control, and sterile storage. Hospitals manage this through precise HVAC systems and IoT monitoring, to minimize airborne pathogens for daily environmental operations. Different hospital zones require specific, highly regulated temperature and relative humidity (RH) settings to ensure safety and comfort.
a. Operating Rooms (ORs):
(1) Temperature: 20°C to 24°C (68°F to 75°F)
(2) Humidity: 30% to 60% RH. Lower humidity reduces the risk of bacterial growth.
b. Patient Rooms & Wards:
(1) Temperature: 23°C to 27°C (73°F to 80°F) depending on the season and regional climate.
(2) Humidity: 40% to 60% RH to minimize airborne virus survival and prevent the drying of patient mucous membranes.
c. ICU and Neonatal Units:
(1) Temperature: 20°C to 24°C (68°F to 75°F).
(2) Humidity: 40% to 60% RH to support patient breathing and protect vulnerable immune systems.
d. Sterile Storage Areas:
(1) Temperature: 22°C to 26°C (72°F to 78°F).
(2) Humidity: Maximum 60% RH to prevent moisture build-up.
e. Burn Units:
(1) Much higher humidity levels (up to 90%) to accelerate wound healing and prevent delicate skin from drying out.
Ventilation Standards by Area Key Engineering Controls
Following has to be ensured:
a. Air Changes Per Hour (ACH): The number of times the total air volume of a room is replaced in one hour.
b. Pressure Relationships: Prevents the spread of contaminants by managing directional airflow. (1) Positive Pressure: Air flows out of the room (prevents outside contaminants from entering). (2) Negative Pressure: Air flows into the room (contains pathogens/contaminants).
Filtration Requirements
a. Primary Filters: Usually MERV 7 to MERV 14, depending on the space.
b. Secondary/Final Filters: MERV 16 to HEPA filters are required in critical care environments like operating rooms and isolation rooms to capture 99.97% of particulates.
c. HEPA Filters: Used for the exhaust of infectious disease rooms and the supply of immunocompromised patient rooms.
Airflow and Exhaust
a. 100% Exhausted Areas: Air from spaces with high contamination risk (e.g., Isolation rooms, soiled workrooms, laboratories, and bathrooms) must be exhausted directly outdoors and not recirculated into the facility.
b. Recirculation Limits: In areas like patient rooms, recirculated air is permitted only if it passes through the facility's designated high efficiency filtration system.
Conclusion
The green healthcare facilities of the future should be equipped with smart systems, have reduced environmental impacts, and achieve maximum patient comfort. Such a development will not only contribute to global climate goals but also improve the quality of healthcare services and lead to more resilient and efficient healthcare facilities.
References
1. Sustainable, green, or smart? Pathways for energy-efficient healthcare buildings. Sustainable Cities and Society, 105013
2. Abd Rahman, N. M., Lim, C. H., & Fazlizan, A. (2021). Optimizing the energy saving potential of public hospital through a systematic approach for green building certification in Malaysia. Journal of Building Engineering, 43, 103088.
3. de Oliveira, K. B., dos Santos, E. F., Neto, A. F., de Mello Santos, V. H., & de Oliveira, O. J. (2021). Guidelines for efficient and sustainable energy management in hospital buildings. Journal of Cleaner Production, 329, 129644.
4. Annura, S., Arabikum, J., Aminingrum, R., Ulu, Z., Wahyudi, D., & Zuhriyah, L. (2022). Efficient and sustainable energy management for hospital building. Journal of Community Health and Preventive Medicine, 2(2), 1-9.