Healthy Building Services

Trade-off between environment and health

When discussing sustainable building services (HVAC, electricity, and water), the main factors that are usually considered are environmental impact, financial cost, comfort, and sometimes safety. Although carbon emission reduction is rightfully dominating the debate nowadays, we must not forget that health can be an important fifth factor when designing sustainable building services. This is made abundantly clear in the PhD thesis 'Healthy Building Services for the 21st Century' of Francesco Franchimon at the Technical University of Eindhoven.

The thesis divides the health considerations for building services into three categories:

1. Fighting infection risks. To accomplish this, the temperature of potable water should be kept under 25 °C to avoid Legionella, and the humidity in the room air should preferably be 50% or more to avoid influenza.
2. Addressing bronchial diseases like asthma, Chronic Obstructive Pulmonary Disease (COPD), and lung cancer. To do this effectively, the amount of dust mites, tobacco smoke, and small particles in the house should be kept low. This can be done by increasing the ventilation in the house from the normal 0.5 air changes per hour to 1 to 2.1 air changes per hour.
3. Support the well-being of senior occupants ('smart ageing'), for instance by installing a videophone and communication tools for telecare and telecure.

Some of these measures to provide health services are clearly in conflict with energy efficiency. A higher ventilation rate for instance — required for keeping humidity high and the small particle level low — will result in a higher heat loss for the house. A trade off will have to be made between health and comfort on one side, and environment and cost on the other.

Sometimes solutions exist that combine the best of both. For instance, to limit the environmental impact of a higher ventilation rate, a ventilation system with heat recuperation can be installed. This kind of ventilation system is standard in passive buildings, but could also be of much use in conventional, well insulated houses to increase the ventilation rate while limiting additional energy loss.