Building ventilation

Building Ventilation

What a huge and complex subject this is, why? Simply few buildings are identical, therefore if mechanical ventilation is being considered, those investigating it require to be very experienced and knowledgeable, in many aspects of how the building is constructed and the current method of heating and existing services.

As an engineer I avoid what I have always called “tech talk/speak” it annoys me, I attempt to deliver my knowledge and experience in as simple format as the subject allows, I don’t need to impress, I just want the subject to be understood by a wider audience.

My views are always mine alone.

COVID has by any measure challenged our Industry to investigate just how MV (mechanical ventilation) can contribute to assisting the Virus to move on and out of a confined space, or keep it in circulation!

What potential cost could be incurred to make your building a safer environment to work, rest and play in?

Some solutions maybe to install UV type air washes working in conjunction with MV or not. This approach may reduce over complex complicated and expensive MV installations. On the other hand ventilation on its own will be the only other choice. This will be music to all the ductwork manufactures around the UK.

MV has for many decades been a poor relation to comfort cooling & heating the “cassette” Sadly such installations have been installed in the belief it provides a measure of perceived ventilation as it “blows hot & cold.” We all know you can add some ducting to the return air, spiral ducting trapping all the dust sucked in from the space below (missing filters or clogged filters, or and in so many cases using the dirty ceiling void as a return air plenum.

Suspended ceilings have been around for decades in various forms, too many to describe here. What they create is a void, the difference in the structural height to the suspended ceiling height. A place where very few visit, other than to maintain or add cabling etc, or plain maintenance.

In many cases the voids can’t handle ductwork in a practical way, so if a space is to have MV it will be within the workspace. Exposed ductwork traps surface dust and all manner of contaminates, Badly designed, it gets turned off because of drafts and not least of all noise.

COVID should not have been the instigator of MV in buildings, WHY? Some may ask. We have in place all the tools at our disposal, the legislation, the professional bodies, the manufactures and installers.

The decision to ventilate a building is in many cases driven by economics, usually what’s the minimum we can get away with, how can we minimise or even eliminate the cost of ventilation.

Ventilation costs to install, it costs to maintain it, and we all see on LinkedIn posts showing the state of ductwork in buildings, possible in some cases a bigger threat to health than COVID itself, why? Well it was there before COVID and will be there after COVID has be sorted.

Those buildings lorded in our journals as wonderful places to be in and work in and win prizes are in the minority, they are few and far between. They do not represent the overall volume of buildings in the UK. The “Oscars” for the chosen few.

In a recent site investigation carried out, the roof space was a complete and utter catastrophe, in simple English a ”cowboy” job. Below the ceiling was an expensive re-fit you name it these offices had all the toys.

Churning of offices is commonplace, resulting in the original HVAC systems being compromised. Open plan being replaced by full height partitions, some spaces had no ventilation or A/C, result complaints, headaches, staff off etc.

I’ve have had my run ins with FM Managers over the decades who thought they knew it all, do the minimum we aren’t getting paid for that! PFI has a lot to answer for in recent times, appoint a design and building contractor and buy or rent it on the never never, doesn’t work IMO.

I doubt the call for building ventilation will deliver the result some in authority are shouting for, always after the event we attempt to put it right?

Fresh air (not sure I call it that these days) actually does cost money, specifically if you design it into a HVAC system, it also requires on most occasions pre-heating to temper it, it can require cooling, it can need dehumidification it also needs filtration, it also requires maintenance,?a lot to think on and it’s not all just about COVID.

So retrofit of good ventilation maybe an expensive solution now, had it been installed in the first place would have been a good investment done correctly.