The Farmers Mart Autumn 2017 - Issue 52 | Page 94

Farm Buildings Ventilation – The natural way Clean air in, stale air out » » WHEN WE TALK ABOUT VENTILATION, what does that actually mean? It is not simply the volume of air in a building, it is actually the rate of air exchange. But let’s go go back to the beginning, and to do so we have to look at what animals do when exposed to nature and consider their rate of survival when left to the elements. Some modern breeds would find it very difficult to live outside all year and cope with the vagaries of our weather systems. Animals out in the open will always look for nature’s shelters, just as humans must do in order to survive. We will always look for simple shelter wherever it can be found. Water, shelter from the elements and food are indeed, the main priorities for survival. On a blustery, wet day, it is unlikely that you would choose to stand talking to someone in the middle of your farmyard. You are much more likely going to move and stand around the corner of a building to shelter from the wind and rain, of course. 94 Autumn 2017 www.farmers-mart.co.uk SHELTER & SHADE Similarly, when the sun is on full power, it is important to find shade. Animals in the natural environment always try to find shelter in the most basic form, whether from sun, rain or winds. They use hedges, walls and natural hollows to get out of or reduce the impact of the winds. They use trees for shade. So, taking a leaf from nature, when we look at buildings we need to stick to the basic principles of nature. All animals want shelter from the wind and rain, shade from the sun and plenty of fresh air. Air movements ideally should be above animal height so as not to create a draft. There are very few days in a year that we, as humans, are glad of a small breeze. We are much more likely to be concerned about the chilling effect of the wind and say it would be better if the wind dropped, and animals are no different - they need shelter from those draughty chilling winds as well. All animals need a shelter wall to be able to lie behind with a decent air gap above for air to pass over. Depending on the height of the wall, the gap above may need some wind break material above it to break wind speed on bad days.