SBS - Sick Building Syndrome
Buildings that make us sick
What exactly constitutes a building that makes humans physically ill? When we talk about buildings that make us sick, we assume that it is the entire building, with all its multiple components, that make us sick. This is in fact not true, nor possible, unless some radioactive or other hazardous materials such as asbestos, have been used in the construction of a specific building. No, it is in fact only certain crucial components within a building, which we aim to identify herein, which make us sick. SBS is merely a phraseology used to describe that certain components within a building, are not attuned with either human wellbeing nor comfort.
Before we can identify the types of building components which make us sick and why and how they make us sick, we need to embark on a short analysis of what actually causes physical illnesses such as influenza, to the more chronic psychological illnesses such as depression.
It is now a well-documented and well researched medical fact that, it is not cold air pursé nor even the short term exposure to cold weather that causes illnesses such as influenza, but it is the increased exposure to the airborne viruses, which are more prevalent during winter and which incubates in air at specific air temperatures, usually in indoors areas where we as humans tend to congregate more during cold exterior weather conditions, which cause these types of illnesses.
There is a distinct difference between being in the cold and being cold. One can be in the cold, yet sufficiently clad and therefor not exposed. If it were true that we contract influenza from exposure to cold weather, then people working externally, such as construction and farm workers, or people living in Alaska or Siberia, would theoretically have been the most affected, but they are not. Ironically and statistically, office workers, whom work indoors, have a higher sick leave absence rate than people whom live and work outdoors.
Yes, exposure to cold and dry weather does have an effect on internal human organs such as, for example, the mucus membrane in the human nasal passages which does consequently have a slight effect on the human immune system, but in the usual short term exposure that we encounter in our modern lives, i.e. walking from your car in a parkade area to a building, or even walking the dog or walking to the shops, or walking from our homes to catch a train, bus, tram or ferry and even jogging for leisure for relatively short burst at a time, exposure to cold weather does in fact resist the incubation of viruses obtained from the air that surrounds us.
Be that as it may, irrespective of the biological or physiological causes of illnesses, the point is… it is not OUTDOORS where we contract illnesses such as influenza or other bacterial infections, but it is in fact INDOORS. Inside our buildings.
So, let’s cut to the chase. The two single most building components that in fact does make us psychologically and/or physically ill in the majority of instances, especially so during the winter months, can be narrowed down to poor or insufficient ventilation and insufficient provision of natural lighting. According to Li Y, Leung GM, Tang JW, Yang X, et al. in a paper entitled The Role of Ventilation in Airborne Transmission of Infectious Agents in the Built Environment, effective ventilation may also help keep bacteria, viruses and other pollutants out of the indoor air. Research now shows that air flow and ventilation can affect how diseases either spread or are inhibited from spreading indoors.
Let’s have a look at the first factor, Ventilation. HVAC is an acronym used to describe the Heating, Ventilation and Air Conditioning in a building. It is the V for Ventilation in HVAC that we are interested in, but more specifically inadequate and/or poor ventilation, in other words the rate or frequency of extraction of stale or saturated air and the supply of fresh air cycles in one hour, also known as Air Changes per Hour (ACPH).
Hospitals, which are buildings where humans conventionally go to be healed, very often end up being buildings where humans die and ironically not due to their ailments, but due to complications encountered after surgery by unsterile environments, as a direct result of inadequacies of specifically required air changes per hour (ACPH), which inevitably and consequently provides a breeding ground for all kinds of lethal airborne viral infections and bacterii.
Apart from very stringent air filtration requirements, certain areas within a hospital such as the Operating Theatre Block, the ICU etc, requires up to 20 ACPH, of which 5 must be Fresh Air Changes. This ensures that the air is sufficiently clean of any airborne contaminants, which could cause humans to contract infections or other illnesses.
It is not being suggested here, that the ventilation in other building typologies, such as hotels and offices, should meet the same requirements as an Operating Room, as this would make most other building typologies simply unfeasible, as these specific HVAC provisions are quite costly, but that careful attention is given to adequate ventilation, as required for a specific building typology, during the design of the HVAC system.
Other than Hospitals and Offices, Hotels are probably one of the building typologies where humans are at highest risk of contracting viruses and illnesses such as colds and influenza. The problem with hotels in general, and once again more so during winter months, is that most hotels possess a very basic HVAC (Heating, Ventilation and Air Conditioning) system. In fact and at best, in the majority of hotels in the world, it is only HAC (Heating and Air Conditioning). The H (Heating) of a hotel room is performed either by wall mounted radiators or by means of a single wall mounted split type AC Unit, but the V (Ventilation) is completely omitted or absent, other than manually openable window sections, which poses obvious practical problems during winter months. Ironically, it is the V in HVAC, that actually ensures human health.
Yes, the H and the AC in HVAC provides for required levels of human comfort, depending on the season, i.e. heating in winter and cooling in summer, but air in hotel rooms, especially during winter when airborne viruses are most prevalent, is not being changed frequently enough, if at all. Hotel rooms generally require a minimum of 2 ACPH at a flow rate of at least 7,5 l/s. What happens in reality is, that the same old saturated, stale air, full of various airborne viruses, is recycled and re-circulated hour after hour after hour within the same confined space. Stale air is not extracted and fresh air is not imported, resulting in virtually 0 ACPH at 0 l/s. Yes, a window could be opened for short bursts at a time, but due to privacy, energy efficiency and/or security reasons, the door into the hotel room cannot be left open and thus, without sufficient cross ventilation, there is simply not sufficient natural ACPH.
It is no wonder that occupants of hotel rooms, actually contract influenza during winter months. To make matters worse, is when an already sick person spends anything between 3 to 6 days in a hotel room, coughing, sneezing and increasing the concentration of airborne viruses into that unventilated, confined space and then vacates the room, only for that room to be re-occupied almost immediately by another healthy person. This is a sure recipe for disaster! The three hours between the required checking-out time of 11h00 and the new occupancy time of 14h00, is definitely insufficient to achieve the required air changes within that hotel room, considering that the room has to still be heated again to ensure the comfort of the next occupant. The healthy person is guaranteed to vacate the room feeling ill. In reality, all the doors and windows in this room should be left completely open for at least 24 hours, before being occupied again, but we all know that financially or from an energy efficiency perspective, this is not even a considerable option.
The solution is that the ventilation of the air within our buildings, MUST meet with requirements pertaining to frequency and rate of changes per hour. One solution for naturally ventilated buildings such as hotel rooms, i.e. not fitted with any means of mechanical ventilation, is that it must be designed with ventilation stacks as part of the services ducts between rooms. These ventilation stacks must be open at the top and must have either a passive or an active means of effecting air flow from the interior of the rooms to the top of the stack and must be controlled by means of dampers at the point of intake of fresh air, to ensure the required ACPH without compromising the loss of heat from the rooms.
Let’s now look at the second building component which is most often associated with causing illness of the occupants and that being the provision or lack of natural lighting.
The two building typologies where we as humans most probably spend the majority of our time, are in our homes and at the office. If we are fortunate enough to live in a free standing house, then generally the provision of natural lighting (or natural ventilation for that matter) does not appear to be a cause of illnesses. However, when we live in high rise apartment blocks or work in high rise offices, then the provision of natural lighting could become problematic and a cause for illness.
Once again, as with the case for ventilation above, we need to embark on a short analysis of the human physiological reaction to the deprivation of natural sun light. It is now also a well corroborated medical fact that sun light provides amongst others, Vitamin D, which is essential for us as humans to remain in good spirit and generally happy and healthy.
Conventionally, buildings in the Southern Hemisphere face North, in order to maximise natural lighting into the building. Inversely, buildings in the Northern Hemisphere face South, for the same reasons. However, practically, penetration of natural lighting is limited to the surface area of the sun facing façade of that building, with a limited depth of penetration, after which rooms on the rear side of the building, being the South side in the Southern Hemisphere and the North side in the Northern Hemisphere, received very little if any natural sunlight.
Yes, there are a number of artificial lighting solutions to mimic natural sun light inside buildings, but there is no solid substitute for good old fashioned, full spectrum, natural sun light. Natural sunlight is a source of Vitamin D and produces this very essential vitamin from the minute sun light touches the human skin. It is now a known fact that Vitamin D aids with many things, from improving the human psyche which leads to enhanced productivity, to faster recovery from other ailments, to less negativity, to the absorption of other minerals and vitamins. And huge quantities are not even required.
One way of overcoming the lack of natural lighting in the rear or secluded parts of high rise buildings, are to provide lighting stacks or atrii, which will channel natural sunlight into these remote areas in a building. It will also have the added benefit of reducing artificial lighting dependency and hence a reduction in lighting based electricity consumption.