Cold Weather Precautions
There will always be the occasional day when cold stops play - if the water is freezing solid on the windows it may be time to go home and have a hot drink! However, there are steps you can take to help prevent this happening on all but the coldest days.
Keep the Van above Freezing Overnight - Generally if you can keep the van warm enough overnight the system will be operational during the day. Ways to achieve this:
- Keep the van in a garage overnight if possible
- Install a greenhouse heater or a small convector heater on a thermostat in the van overnight
If this is not possible then follow these tips to prevent a freeze-up of vital equipment:
- Keep the poles and hose reels inside overnight
- Take indoors your DI vessel if possible
- Drain any hoses and pipes in the van at the end of the day – install a shut off valve at the tank outlet and then drain any water in the rest of the system
- Drain and Insulate the pump overnight (remove when using to prevent over-heating)
- Starting from this point it would take a very cold day to prevent you from working as about the only thing that can then happen is the water can freeze in the Microbore hose as it lays on the ground - this will only happen though if you run it out and do not start using it straight away.
- Take any backpacks indoors overnight – freezing will damage both the battery life and the pump in the backpack.
Protect your RO - If using an RO based system, either in the van or in a building, then ensure that it is fully insulated as freezing will ruin the membranes and may crack the housing. Just one exposure to frost can permanently affect the cell structure of an RO membrane.
Hot Water Systems – These can help to prevent freezing on the glass and during the days work, but at night the previous points apply as the van, pumps, pipes can still freeze solid in the van overnight and if not thawed out can cause very expensive damage
An alternative is to have installed and use a Frost-Stat Hot Water System which will switch on to keep everything above freezing during the night if needed. Whilst this is usually the most expensive solution it will ensure that less days are lost to the cold.
Working in Freezing Conditions
- If working in areas where the water will run off the windows and across public footpaths, then ensure that you spread some rock salt or similar over the area before leaving
- If using a hot system make sure that you turn down the temperature by at least 10-20 degrees as the glass will be a lot colder than normal and the sudden temperature change can crack the glass.
- If working with a cold-water system then do not leave the reel hose fully wound out on the ground without the water flowing for too long – static water in a small bore hose can freeze up very quickly on frozen ground.
Keep more spares on hand during the Winter – when temperatures drop to zero then plastic items and components can become more fragile and break during use. What sort of items is it advisable to have spares of in the winter:
- Small plastic components such as fanjets, push-fit T connectors etc.
- Pole hose becomes less flexible and can result in splits due to freezing weather – keep spare pole hose in stock or a hose mender
- Pole clamp levers etc. can become brittle if knocked when frozen
- Plastic hose couplings
What about adding chemicals to the water tank to prevent freezing?
Whilst some claim that adding chemicals such as Isopropanol to the water in the tank will prevent freezing, the dosage that would be needed to achieve this would be so high that the cost would be very high and probably not sustainable. A chart below shows the exact proportions needed to affect any ‘antifreeze’ effect:
- 1 Litre in a 500 litre tank – 0.2% Isopropanol:99.8% water will have no measurable effect on reducing the freezing point of water
- 50 Litres in a 500 litre tank - 10% Isopropanol:90% water will reduce the freezing point of water from 0° C to –3° C
- 100 litres in a 500 litre tank - 20% Isopropanol:80% water will reduce the freezing point of water from 0° C to –7° C
- 200 litres in a 500 litre tank - 40% Isopropanol:60% water will reduce the freezing point of water from 0° C to –20°C
Fact - the water in the tank will be the very last thing to freeze up. Even if it does freeze then it will freeze from the top down which generally will not affect your ability to work. Keeping your pipes, hose, pumps and poles above freezing will be far more effective in keeping working than adding chemicals to the tank.
Warning – If you do decide to add Isopropanol or any other ‘antifreeze’ chemicals to your water tank, you would also need to carry out a risk assessment and a method statement for using such chemicals in a way that would dropletize them and allow them to be inhaled by either yourself or those near you whilst you work.