Setting the Standard for Healthcare Energy Systems

Healthcare facilities use a significant amount of energy. At the same time, they are subject to strict regulations designed to protect the safety, comfort and health of patients and staff. Here is a summary of important healthcare standards and guidelines that impact HVAC, water heating and lighting systems.

HVAC

Section 3 of the Centers for Disease Controls and Prevention (CDC) Guidelines for Environmental Infection Control in Health-Care Facilities focuses on filtration and air cleaning to achieve high indoor environmental quality (IEQ). Ultraviolet germicidal irradiation (UVGI) can supplement but not replace HEPA filtration, air exhaust or negative pressure.

ASHRAE 55: Thermal Environmental Conditions for Human Occupancy addresses air temperature, humidity and airflow. ASHRAE has defined both summer and winter target conditions for temperature and relative humidity (RH):

• Summer — 72°F to 82°F and 25% RH to 70% RH
• Winter — 70°F to 75°F and 30% RH to 70% RH

ASHRAE 170 Ventilation of Health Care Facilities offers guidelines and mandates for designers of healthcare facilities:

• Minimum air filter requirements are typically MERV 8 to 14 or HEPA.
• For ducted exhaust systems in lieu of return air systems, 170 allows use of displacement ventilation (DV) for single-bed patient rooms.
• Energy recovery ventilators shall not be used at all for airborne infectious isolation room exhaust systems.
• Reduced total air changes per hour is allowed in unoccupied patient rooms provided that required pressure relationship to adjoining spaces is maintained and the minimum number of air changes required is re-established
• Relative humidity levels of 40% to 60%. Lower RH limits — down to 20% — are allowed for short-stay rooms, reducing energy consumption and condensation issues.

The standard also includes guidelines for the location of ducting outlets and inlets, the number of air changes per hour and room pressure differentials.

Chapter 9 of the NFPA 99: Health Care Facilities Code covers the performance, maintenance, and testing of HVAC systems in healthcare facilities. It recognizes four levels of system categories based on risk to patients of mechanical equipment failure. NFPA 99 requires HVAC commissioning in accordance with the ASHRAE 90.1 building energy standard, as well as removal of excess anesthetic gases and capture of plumes from laser surgery.

The Joint Commission’s Environment of Care® standard EC 7.10.16 Ventilation Systems covers proper pressure relationships, air exchanges per hour and filtration efficiencies. An upgraded HVAC system makes compliance much easier.

Lighting

The Facility Guidelines Institute (FGI) Guidelines for Design and Construction of Hospitals and Outpatient Facilities requires that medication safety zones and pharmacy areas meet lighting standards as published in the U.S. Pharmacopeia-National Formulary. These include:

• Task lighting is required in areas where critical visual tasks are performed if illumination levels are below recommendations.
• Illumination levels for computer order entry areas should be at least 75 footcandles (fc) while 100 fc of illumination is recommended when handwritten orders are read.
• Prescription preparation areas, medication inspection stations and counseling areas should have illumination levels between 90 fc and 150 fc.
• In food and nutrition areas, occupancy sensors are required for all offices, restrooms and storage areas.
• Light levels should be measured on a quarterly basis.

Water Heating

The FGI guildes also cover hot water use. For general hospital clinical use, water temperatures between 105°F to 120°F are required. For warewashing 180°F rinse water is required unless a chemical rinse is provided. Also, water at 160°F shall be available for laundry use if needed.