Top tips to keep your tractor air con in order

Air conditioning, like many of Britain’s major sports teams, tends to disappoint after a few years.

We consulted Cornwall air-conditioning specialist Ball & Ball Farm Services on what we should be doing to keep things up to scratch.

Dealing with 2,000 machines each year spanning from Somerset to Land’s End, air conditioning experts Jon Ball and his son Sam have been working on agricultural and quarry machinery air-con systems in the south-west for the past 18 years.

The company can complete almost all work on the day because compressors, condensers and pipework are carried on board. Some condensers are tractor-specific so must be bought in, but often it’s the same problems that crop up again and again.

So, if warm air is billowing from the vents of your tractor’s air-con, or if it isn’t blowing at all, there’s likely to be a relatively simple answer. Here’s a list of the most common problems, all of which will need some professional help.

  • If it’s not blowing at all then check the cab filters and evaporator for debris (some cabs have no filters for recirculation of air).
  • Regular freezing due to a broken thermostat will cause a loss of airflow and damage to the evaporator box; contact an engineer if you suspect a problem.
  • A leak in the system could well be as simple as a pinched O-ring in a fitting. The quickest way to check this is to have an engineer conduct a pressure test. This involves charging the system with nitrogen to 150psi and using an electrical leak detector to spot leaks.
  • A perennial problem on any farm is rat and mice damage to combines over winter. They’ll chomp their way through pipe-work given half a chance so try and keep them out.

With farmers spending more hours in the cab than ever before, fixing up the air-con should rank highly on the pre-harvest to-do list. While you might expect high-spec tractors to offer fridge-like temperatures, you can save a lot of time and money in the future by keeping on top of basic maintenance.

“Often it’s just down to keeping the system clean,” says Sam Ball. “Not cleaning it out will limit the airflow through the condenser causing poor condensing. The result is high pressure in the system and no cold air in the cab,” he says. That might end up with a clean-out bill from your local air-con specialist.

We wanted to know what we should be doing to keep things ticking over, so here are Sam Ball’s top six maintenance tips.

  1. Over winter, tractors and combines should be fired up for 20min every couple of weeks to keep gas moving around the system. Up to 10% of gas in the system can be lost each year leaking through dry pipes and seals but running it up should prevent this.
  2. Rubber-mounted engines jiggle about more during work, which can cause pipes to wear and gas to leak. Keep and eye on any potential problem spots where pipes may chafe. If you can relocate the pipe by half an inch using a cable tie, do so.
  3. Keep filters and condenser clean. On modern tractors there’s no excuse – just run an airline from the tractor’s air-brake red line. A blocked condenser can cause problems for the viscous fan, so keep it clear.
  4. On Claas forage harvesters make sure you check the side of the condenser you can’t see in the rotary screen.
  5. Bear in mind that the gas won’t last forever – most tractors will probably need re-gassing every three to five years depending on hours and workload.
  6. Mr Ball suggests a specialist service once a year or every 3,000 hours to remove the gas, change the receiver dryer, and clean out the filters and condenser before re-gassing. A service like that will set you back £120-180, but should make sure of a relatively sweat-free harvest in the combine.Serviced regularly and kept clean, Mr Ball sees no reason why a unit shouldn’t outlast its owner. “Kits we fitted 15 years ago are still working today and older systems often last longer because of the cost cutting involved in today’s tractor manufacturing,” he says. “Often we find the condensers are small and the pipe-work is thinner.”

What if you want to fit air-con to a tractor that doesn’t have it in the first place?

Ball and Ball will fit a factory-spec air-con unit to practically any cabbed tractor for £1,600-1,800 including all the parts and labour. Better still, it can be done on-farm in about five hours and doesn’t cause any damage to the cab structure – pipes and wires are slotted through existing holes.

In fact, it can add up to 5% to the value of an aging machine.For more information on servicing and fitting in the south-west go to

Most reasonably-specced modern tractors, combines and foragers now come kitted out with the slightly more sophisticated climate control.This monitors temperature in the cab and compares it to the temperature specified by the operator and adjusts accordingly.

Climate control works more precisely, maintaining a constant temperature in the cabin by turning the air-conditioning and heater units on and off.

A standard air-con system, on the other hand, cools the cab until the compressor kicks out to prevent the system freezing. That’s why on moderately warm days getting the vent breeze the right temperature is a pretty tricky task.

In terms of keeping the cab fridge-like, though, there are few advantages of the climate control system. It often only works down to 16C, although it is possible to fit a bypass switch that will drop the temperature as low as 6C.

Having a professional spend most of the day fitting a factory-spec unit isn’t the only option.

French manufacturer DDPA is now selling its nifty-sounding Hygloo GIII in the UK. It’s a quick-fit system that works off the 12v socket in the tractor cab, so the whole unit is battery-powered.

The compressor and fan sit on the cab roof in a neat little box (they can be mounted on any flat exterior surface). It does add a little extra height to the tractor, though, so be careful when poking around in low-standing sheds.

Because it can be bought pre-gassed and with special connectors so that pipes can be cut to length, Isle of Wight-based importer Auto Air Con Services reckons it can be fitted by a farmer in just three to four hours.

It will mean taking a drill to the cab roof, though, so it will have to stay put once fitted. It may have a lower output than a fan-belt-driven system, but should be adequate for moderately warm British summers.

Expect to pay about £1,950 for the Hygloo unit – more expensive than a factory fit version but it might be a little easier to get set up.