How does Ventilation work? A Brookvent Guide

It may seem like a simple question and the answer is fairly straightforward, but sometimes it is good to think about the basics. Often we have missed some fundamental truths that will make a big difference. Ventilation is one of those areas that is often taken for granted and that can lead to mistakes.

Ventilation is taken for granted

We probably all understand the need for air. But just by breathing, we are contaminating our indoor environment so we must replace stale air with fresh air. If we have a fire with an open flame, perhaps a gas heater or a log burner, the device will replace oxygen with carbon monoxide and that can affect our health. When we breathe and sweat (we all do it), we add moisture to the air. If the moisture remains, it will foster mould/condensation and, because the water in the air takes up the heat, it will increase your heating bills. So sub-standard ventilation could increase our bills, spoil our possessions and make us feel unwell. None of these are desired but we often forget to think about it.

So, we need to take our smelly carbon-laden air and move it outside. If we have an extractor hood on our cooker or an extractor fan in our bathroom we could turn those on and that will expel the air. That is a key element in removing moisture-laden air. We make our bathrooms and kitchens extremely humid when we shower or cook. We don’t want to spread that dampness around the house so we suck that air out where the problem is caused. Check out our range of extract fans.

So, what is replacing the wet air that we are pushing out? Well, it’s the air from the rest of our house. If we took this to a finite degree then it would be like the experiments we did at school where the air is sucked out of a sealed container and we are left with a vacuum. Of course, the fan is not that powerful and our houses are not sealed airtight. So air can come into the building to replace what has been removed. But where does it come from? Once upon a time, our houses were very leaky and air came in all over. Through the brickwork, around the roof tiles, and those draughty windows.

But less so now. Our houses are well insulated and our windows don’t rattle in the wind. So we have to arrange to let the air in a controlled fashion. The classic solution is the window vent. It lets in just the right amount of air, the design and positioning mean you don’t feel that air being gently replaced. It all works well. Check out our range of Window Vents

However

What if we are not turning on those extract fans? Does ventilation happen then? The answer is hopefully yes. Some properties have a constantly running extract fan. This is generally where the windows are all on one side of the building. Perhaps a flat or apartment. These fans work quietly to keep the air moving. But in the majority of properties, the natural environment will give the power to provide ventilation as long as we don’t get in the way.

As a breeze blows across your house it will leave a gentle eddy on the downwind side. This eddy will mean that the pressure is lower on the leeward side pulling air from your house just as the extractor fan would when it is turned on. It will pull air out on the downwind side and that will draw air in on the windward side, physics in action. There is also the “stack” effect. That is where hot air will rise. Hot air rising through your house will if it is allowed to, exit through the upstairs window vents drawing in the fresh air downstairs. All very natural but we humans can cause problems.

I would like you to imagine you are holding a short hose. Now blow in the hose and the air flows through and exits at the end. What if you have an empty bottle? Put the neck to your lips as if you are drinking and blow. Pretty much nothing happens. The air you are trying to blow has nowhere to go. It doesn’t matter how hard you blow there is no flow. So the key to flow is an opening to let air in and an opening to let the air out with no impediment in between. And this highlights a problem that often occurs in modern houses.

Building Regulations

The building regulations require internal doors to be set to allow air to pass underneath to complete the airflow across the house. The house is designed that way and built that way and somebody buys it. The new inhabitant wants to live in comfortable conditions, so they buy a beautiful thick carpet. Fortunately, the door was built a bit short, so it won’t need easing. Now the door scuffs gently across the top of the carpet and the owner feels happier knowing they will not experience draughts.

However, we in our enlightened state realised that these actions have stifled the flow and the owner will not be benefitting from the fresh air that natural ventilation would provide.

Therefore…

So it is very simple. Ventilation has a positive effect by replacing stale polluted humid air with fresh air. As long as there is a path for the air to follow you will get the flow and will see the benefits. Always remember that air is sucked through your property so make sure you allow that to happen.

Contact Us

If you are considering any form of ventilation systems as an option for your property/build Click and get in touch with Brookvent today! We are residential ventilation specialists, and we will help you at every step of your project.

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