Free Cooling, Covid and Contaminants in Buildings
by Mike Hardy, April 2021
It must now be time to air Covid 19 things,
And contaminants like that in our — buildings,
Our buildings are so well sealed — some highly occupied now,
We must look anew as to search for the how.
…to ventilate that is — and minimise the spread,
Of virus and bacteria so folk do not dread,
To occupy buildings all the world over,
And feel safe with high efficiency filtered outside air — moreover.
Most ventilation systems mix the air,
It is called ‘mixed flow ventilation’ and used everywhere,
It has been used in buildings for many years,
But now if we continue will fulfil our greatest fears.
A good idea is air from outside to enter a room from the floor,
To rise up to the ceiling — and what’s more,
For this air to move away vertically from the breathing zone,
And to be exhausted at high level — say through a dome.
This ventilation system it has a name,
It is called displacement ventilation and in the game,
It is used now and then but hardly anywhere,
We must reverse that now and use it almost everywhere.
Research shows with the displacement effect, the contaminants reduce,
From occupant to occupant and that is of much use,
For keeping our buildings healthy and clean,
Which is what we need — that is clear to be seen.
For independent and published work if that is sought,
Look no further than royalsocietypublishing.org/doi/10.1098/rsos.200680,
Of course there are others but this is a good start,
In our determination for clean and healthy buildings to play their part.
The manufacturers and suppliers of the products are well established and exist,
Research laboratories also for bespoke air building simulation and tests,
A major concern of course is the energy for cooling or heating 100% outside air,
This is something we must solve to enable the use of these systems everywhere.
Energy heat recovery products and design ingenuity has progressed so much it is clear,
As much as 75% energy air recovered from exhausted air to atmosphere,
So why not modify existing and design all systems like this as a task?
It is a question that building designers and we all must now ask.
The demand for requiring heating in many new buildings is less that it has ever been,
Because of the high standards of insulation and the building tightness it can be seen…
Energy hungry cooling is becoming the major requirement everywhere,
It is now vital to absolutely minimise the energy required to refrigerate the air.
Whilst analysing energy requirements for building — consider this thought,
In most temperate countries cool air outside is mostly not used to cool buildings — as it ought,
But often recirculated air is refrigerated instead — you see.
So colder air outside is mostly wasted for the use of free cooling energy.
Hot climates without the benefit of cooling outside,
Have the huge advantage of the sun for electricity which solar panels will provide,
Cooling systems utilising this electricity are clearly the way to go,
This needs thought, originality and ingenuity we all know.
What we must be sure of is hot countries must not follow the norm,
Innovative cooling techniques using less and less electricity would be the form,
Absorption equipment requiring heating for regeneration and electricity both using the sun is one way to go.
And there is a world competition for cooling equipment innovation — globalcoolingprize.org — you must know.
Shaded air inlets and water sprays are already used but not a lot,
The correct application of displacement reduces size of cooling plant — more often than not.
The net effect of this will be much lower energy use,
Less maintenance costs as well so much to gain an nothing to lose.
There are pluses; the deadly Covid epidemic paradoxically will assist…
To make us think again now and for us to enlist…
All our imaginations, to be inventive and prepared and more than that,
For us all to work together and co-exist happily on this planet.
But is there such a thing as specialist air distribution designers, (needed for each building) exist? — well yes there are,
They are essential to work with owners for optimum performance by far,
The building team and owner must work closely together for the best solution,
For clean and healthy buildings quite free from pollution and also contribute hugely to the green revolution.