KPH Safety First
As a forward-thinking company, we continually strive to manufacture quality horseboxes that are safer, reduce stress and have increased durability.
The KPH innovative safety designs have many years of research and development behind them.
Over the next few months, we will post some of our research topics including insights, and considerations that we use to design safer horseboxes
Hopefully, these topics will be something horse owners will find insightful and interesting.
7. Horsebox Heat and Ventilation
Without question, there is plenty of research on the effects of prolonged exposure at high temperatures and how it causes heat stress, heat stroke, dehydration, muscle spasms and colic in horses. Heat and ventilation should be a fundamental part of any horse area design, yet for many builds, it doesn’t look like it is even a consideration!
Heat removal and ventilation is an area we continually monitor. Having seen major changes in UK weather cycles and with the heatwaves of the past few years, we invested even more resources into understanding what was actually happening in the horse area. From our findings, we have upgraded our systems considerably to provide better air flow, much improved heat removal and to some extent, a better understanding of how it all works for our customers.
Of course, air conditioning units would be the best option for any horse area, and we do fit them to our larger horseboxes. Unfortunately, for the smaller sized models, the cost and extra weight, limit their popularity.
Lazy Air
We already know air is lazy, this adds a level of complication to designing an efficient horse area. A brief example using an extraction fan in the ceiling (bearing in mind our goal is to remove hot air and draw cooler, fresh air across hot horses). So, it’s a hot day and your loaded with horses, all the windows are fully open, and you turn on the fan to keep them cool. Now, Mr Lazy Air can’t be bothered to travel all the way across your horses and cool them, his choice would be a direct route from the nearest open window straight to the extraction fan. Some hot air will still be removed, but the cooling effect on your horses will be much reduced.
The better option by far is to narrow the openings on the nearest windows to the fan (or if you are moving, roof vent) and make the furthest window openings larger. Now, he has no easy rout to the extraction fan and all his options are the same effort. This will pull cooler fresh air across the horses, giving the best possible cooling effect.
Our research findings
Our research looked closely at heat from conduction, heat from convection and thermal radiation.
Firstly, we considered the volume of the horse area and where the heat collected. Using a thermal scanner for heat detection, we noted how much the outside paint colour of the horsebox affected the internal temperature. We also noted that the hottest part of the internal volume was the top third around the horse’s head and above.
We then considered solar gain through the windows. In direct sunlight this adds considerably to the internal temperature. It may look odd, but the ideal for horse window colour would see us use mirrored glass, as it reflects the most direct sunlight. Although they are not the very best solution, darkly smoked glass is the next best compromise, and it is certainly one that adds to the overall aesthetics of a horsebox.
Horse area windows and roof vents are essential for quality air flow and heat removal. Using a fog generator gave is a clear understanding of how air moves around the horse area and greatly aided with the amount and placement of windows and vents. This testing was in fact a revelation and the reason we have redesigned the Aeos horsebox models with a low-level fresh air delivery system.
Once testing was underway, it quickly became apparent that customers would have no idea how hot the horse area and horses would actually be. We needed a robust heat probe and gauge for the cab!
The size and placement of the widow openings plays a crucial part in the overall cooling effect as they draw fresh, cool air across the horses. If we consider just the window placement first. An efficient design will see large horse head windows with smaller tail end windows. This differential in window size is crucial. It allows air flowing past a moving horsebox to cause a greater vacuum at the larger windows than the smaller ones. This vacuum effect draws air into the horsebox through the small windows, across the horses and out of the larger head windows.
It is worth noting that window opening sizes play a crucial role for a moving horsebox. Ideally window openings should be as large as possible. However, if both head and tail windows were the same size, the air pressure would be equal on both sides of the horsebox, and little to no air would move inside the horse area. It is also noteworthy that for hot or stale air to leave the horse area, fresh clean air must have a way in.
A more efficient system would see a roof vent added. So, when the vehicle is moving with the vent opened at an angle, it will cause a greater vacuum than the windows, therefore a larger volume of air will be drawn from the head and tail windows, across the horses and out of the roof vent. This arrangement will remove the most heat from the horse area and replace it with cooler fresh air.
For a stationary horsebox, adding an extraction fan would have a similar effect to a horsebox with a roof vent. However, for optimal performance the roof vent must be fully closed when the extraction fan is used, otherwise it will draw air directly from the roof vent straight to the fan.
Designing the horse area in our horseboxes
Even with insulated sides, in the sunshine, darker paintwork transfers considerably more heat to the horse area than a light colour. The choice always lies with the customer, and we just advise that lighter colours transfer less heat.
For all our models we include a white roof as standard!
Fortunately, our horse areas are stalled for the largest horses. Our Aeos range having 2.43 meters (8’) internal height and the Helios range from 2.51 meters (8’3”) to 2.59 meters(8’6”) internal height. This help somewhat in keeping the very hottest air up above horse’s head. To help remove some of this heat, we install the horse area windows as high as feasible.
To reduce radiated heat through the windows we use the darkest smoked glass.
Having the lesser volume in the horse area than our larger models, our Aeos horsebox range now includes low level vents. These vents deliver cool, fresh air underneath each horse. The cool air is then drawn up around each horse towards the windows and roof vents or extraction fan.
To keep track of the horse area temperature we include an internal horse area thermometer with a digital readout on the dashboard.
We have optimised the vent, roof vent and window size and configuration for maximum cooling and fresh air delivery on all models.
From customer feedback, we noted that however hot the weather, sometimes a trip is just unavoidable. Taking this into account, we have moved the horse wash attachment point to the locker closest to the horses. In an emergency this allows the hose to reach each horse with cold water.
Finally, as part of an overall heat and ventilation strategy, when we hand over a new horsebox, we have added an in-detail explanation of air flow and heat removal.
Food For Thought…
Safety and primarily horse safety is at the forefront of everything we do. Having said that if there is something we have missed or something you would add, we would be very interested to hear from you.