How to prevent or delay water troughs from freezing in cold weather.
With colder weather forecast for many parts of the UK in the near future and, of course, with conditions below freezing in many parts of North America, we thought we would look at a suggested method of delaying or preventing freezing of water in drinking troughs.
The idea is that an empty 5 (~1.5 US gallons), 10 (~2.5 US Gallons) or 25 litre (~6.5 US Gallons) black container placed in a trough will delay or even prevent the water freezing. The rationale is twofold. Firstly, that the movement of the container on the water surface disturbs ice formation and secondly, that black absorbs radiant heat and keeps the water.
Movement
It’s not uncommon to see “tips” to use plastic bottles in troughs to delay or prevent freezing. Water freezes at 0°C (32°F), but in still conditions, the surface layer cools quickest and forms ice crystals that can spread. Movement from a floating object agitates the surface, making it harder for a stable ice layer to form. This mimics how flowing rivers or streams resist freezing compared to still ponds, as the motion prevents supercooling at the top and circulates slightly warmer water from below. However, this method isn’t foolproof; in extremely cold or prolonged sub-zero temperatures, the water will eventually freeze regardless, though the delay can be significant (hours to days depending on conditions. But it’s most effective when there is movement of the container caused by wind or animals nudging the containers.
Colour
Black containers will absorb more available solar radiation than clear or white containers. This absorption converts sunlight into heat, which transfers to the surrounding water, raising its temperature slightly during daylight hours and making it take longer to reach freezing point. However, this effect is dependent on sunlight and is therefore most pronounced in areas with ample winter sunlight and may not prevent freezing entirely in prolonged extreme cold. Using black troughs also has the same effect.
If you are going to insulate a field trough, use a black material or paint the outer insulation black!
Bottom line
Black containers floating in water troughs can delay freezing!
Have you used this method?
