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.