What about the elephant?
Since the SARS CoV-2 virus found its way all over the world ( the CoV-1 in 2007 did not make it far out of Hong Kong ), we have to review many concepts, and preferably adjust our ways of living, if we do not want to suffer in very unpredictable ways.
To us, as architects, probably the most important elephant is about the (lasting) spatial impact of the pandemic.
Today, at the beginning of the pandemic, we are facing disruption in how we live together and how we use space: we glue lines, count people, wear masks or keep distance and we start worrying about air movements…
We now have to rethink how we pass by each other, how we stay close or not close to each other and with whom, how and when to wear masks etc..
Our buildings, in the meantime, will be expected to deal with air purity ( medically speaking), i. e. with flows of air, but this shall need not be consistent also with flows of people, flows of heat ( no waste of heat) and with our building substance and lay out (materials and geometry).
That, put together, is the new reality that will bring with it new design conditions to be met, which will lead to new design outcomes
what shall we take into account for this new design?
How close is too close?
The actual directives of social distancing are not 100% accurate, they rely on test on standing people, not moving and indoor air that is not moving either …
We shall need to finetune this and then bring it into our habits, maybe also indicate this spatially.
Exhaled air, forced,
is different from breathing out
from 60 to 100 –fold increase when we force air out is a lot,
Social distancing is for “normal” breathing out, coughing and sneezing.
Aerosol is the next thing
Florence Nightingale knew already 2 centuries ago: the illness travels through the air …
More technically this is expressed as the aerosol route, small particles ( less than 5 micron) are carried by air and encounter the same lifting and moving forces as larger objects in heavier fluids ( remember , air is a fluid, to such a small particle, it feels like for us when we are in a swimming pool…).
The issue the next months shall be that we shall, again, need to refine our internal spaces to get them fit for the increased requirement.
This is exactly what happened to houses and public buildings in the 19th century; ceilings went up ( at least for the welathy), ventilation chimneys etc. were introduced, in care buildings compartmentation became the rule and the airflows went from clean to dirty since then.
There is no reason thinkable why we should not adapt our buildings and spaces again this time …
How to know, what to design
New ways of organizing and designing air flows, are based upon simple concepts, warm air is light than cold air and moves up, moist air is lighter than dry air and moves up also.
Movement of air creates less air pressure in that area, which means air is being drawn towards it.
The dynamics used properly, make air move.
Next step now is to understand how and to which extent.
Once we know this, more or less accurately, we can introduce controls ( to know what is happening) and acting elements ( valves, dampers, etc.) to ensure consistency between what is needed and what is provided in terms of air quality.
Stepping out of the hospital environment, the elephant of healthy spaces is since shortly, accepted as being there. No longer can we deny that our air flows do impact on our health and wellbeing and that these air flows are intimately related to the space, the air movements, the ventilation design etc.
Attempts, such as the above one from the University of Oregon, try to bring this understanding to a larger public, the rationale is questionnable, but it proves how this is now suddenly “visible”. Designers need to adress this properly.
SOUNDBITES from a world in overdrive…
1.AIA Releases Design Strategies for Safer Schools post COVID-19
2.New York’s Open Restaurants Program for Outside Dining to Be Made Permanent
3.Covid-19 Has Raised the Question: Why Do We Design Buildings? ( this is a nice one, do go read it)
4.Tips for Architects Working At Home During COVID-19
5.How to Transform a Polluted Indoor Environment into a Healthy Home ( nice article too)
When the culture changes, either voluntarily or kicking and screaming, architecture naturally follows.
( phrase by architect Duo Dickinson)
what is the issue with air ?
Contrary to the fact that we do not see “anything” floating around in air, usually and that we take this essential life material for granted, as it is a real gas, it is mixed with anything that can get airborne: moisture, dust, germs, viruses, but also toxic material and, last but not least, anything we can “smell”> odour.
For very long, it was considered absolutely unnecessary to adress air as a material when it concerned architecture.
In architecture, it is/was mostly seen as the void around which the actual ‘architecture’= floors, walls, roofs was being organized.
If air was considered interesting, it was only for the filling of that void, allowing us to see and appreciate the geometry of the space, the play of light and sound in it…
In reality, it is in a way more important for our life to design the airflows we breathe, than to see them as the carrier of a form, made by walls and floors and roofs.
In fact, on many occasions, even what we consider still to be architectural form is the consequence of a conscious and intended organization of the flow of air, for reasons of energy exchange or for reasons of health and wellbeing.
This is the floorplan of the largest “hospital” in the world in the 16th to 18th century, the hôtel Dieu in Paris. Beds were aligned in rows in huge surfaces without any knowledge of flows, hygiene was unknown. Mortality rate was on average beyond 25%, which is huge.
This is the floorplan of the hôpital Lariboisière, also in Paris, one century later, 19th century: nursery wards are aligned, seperately with enough distance in between. These wards were also called Nightingale wards after Florence Nightingale, the nurse that studied the mortality and its solutions and came up with the ideas of distancing, hand hygiene and ventilation.
Since the 19th century the scientific data supported concepts of healthy buildings, changing form, space, typologies … thus saving millions of lives
The very first canon of nursing, the first and the last thing upon which a nurse’s attention must be fixed, the first essential to a patient, without which all the rest you can do for him is as nothing, with which I had almost said you may leave all the rest alone, is this:
TO KEEP THE AIR HE BREATHES AS PURE AS THE EXTERNAL AIR, WITHOUT CHILLING HIM
( Florence Nightingale “ On Nursing”)
Designing air flows
Can we organize our design in such a way that we can direct airflows for our living conditions?
Are there possibilities to substitute machinery and technology with passive design solutions that are more sustainable, more healthy and less energy consuming?
As described in Sun, Wind, Light, there are already some firm design approaches available to us and designers should start using them more, and better ( -again)-
Two main approaches for ventilation are available: 1.bring the air through the building in a more or less horizontal way, called cross ventilation, using pressure differences of wind, or 2.Use the pressure and temperature differences of air to create a vertical airflow, called stack ventilation to refresh air and/or either heat or cool a building
These approaches are only effective when
a)the building size, geometry is appropriate,
b)when the climate conditions are positive and
c)when the use of the building is compatible
(The handbook Sun,Wind and Light basically describes the different interrelated ways in which a designer can design to optimize the result taking into account the above)
