It's sometimes easy to overlook how the "mechanicals" contribute to design success or failure BY PHILIP E. BANNAN, CPSM
When all systems are go, they keep us going. The heating, ventilating, and air-conditioning (HVAC); electrical; plumbing/drainage; and communications systems of a building are its living, breathing components. And as important as they are for apartment buildings, offices, and schools, they are of the utmost concern for senior living facilities.
One reason is the critical importance of resident comfort 24/7. During the colder months, it is essential for an HVAC system to maintain temperature and adequate humidity to provide a comfortable feeling of warmth while minimizing dermatologic problems for aging skin. The system must also provide for proper exhaust, filtration, and the introduction of fresh air to prevent odors and airborne pathogens.
Another reason is that rising energy costs make prudent design and equipment decisions critical to continued operations. As the accompanying chart demonstrates (figure), over the course of 20 years, the cumulative cost of energy will amount to 35 times the first-year cost!
Realization of energy savings therefore requires a dual approach: (1) selection of an HVAC system that has economical first costs, provides heating and cooling economically and efficiently, is easily maintained, and provides an attractive return on investment; and (2) immediate implementation of a targeted, sustained maintenance program. The choices for an HVAC system are many and include:
- Direct-expansion split or through-wall system. Developed for residential applications, this system is familiar to residents. However, despite the first-cost savings, these systems are expensive to operate and maintain, and are noisy, as well.
- Behind-the-wall, ducted system with air- or water-source heat pumps. This system is beneficial because it delivers air quietly and with gentle air distribution. Energy efficiency is also greater with a heat-pump system. A ducted system is, however, difficult to retrofit in existing facilities because of its space requirements. The added cost of increased ceiling heights in new construction and the initial cost of ground-source systems are further considerations.
- Remotely piped chilled-water system. This system will provide the most convenience and comfort for residents. It is the second most energy-efficient of all of the systems and offers the further convenience of a mechanical room where maintenance can be performed without disturbing residents. While a central chilled-water plant system is the second most economical in terms of life-cycle analysis, it has the highest first cost and is therefore better suited for CCRCs with multiple buildings than for a single, stand-alone nursing home or assisted living facility. It also requires a sophisticated maintenance program.
The table compares initial costs, operating costs, and simple paybacks for various systems.
The Design Team
The key to achieving your goals of comfort and safety for residents and staff, along with economical operations, is your design team's selection of an architect and engineers. It is important for team members to have recent and relevant experience in the design of facilities for older adults. While the architect generally has responsibility for project coordination, general construction, aesthetics, and interior design, it is the engineers who have responsibility for system selection: the HVAC, electrical, plumbing/drainage, and communications/security systems that will work best for the building. (For examples of the difference they can make, see "Case Stories".)