Air con always on?

[Baytree]

People on this forum probably have fuel economy on their minds because of the kind of cars this forum is about. But as air-con reduces MPG to some extent, you may be tempted to switch it off when not strictly needed.  
 

Would anyone care to comment on advice from the Honest John writers that air-con systems are designed to be left on full time?

Anyone heard of a warranty claim refused because it was switched off from time to time and it failed?

Haven’t got my new Cross yet but do the new Toyotas remember to switch it back on for a new journey?

[FROSTYBALLS]

We leave ours on all the time - winter and summer - and have done for the best part of 20 years plus. In winter, as air con dehumidifies air, it helps provide faster demisting when used in conjunction with the heater. Rather be comfortable than too worried about fuel economy.

See - 

 

[Tomv]

I just turn it on in hot summer days and only when I drive for 15 min or more or to defog front windscreen. Otherwise it's off.

I'm sure that you will get only two types of answers here - leave on all the time - turn on when needed, choice is yours 🙂

Does not make sense to refuse warranty claim if you have button to turn it off and in manual there is no note about the need to have it on all the time.

[Stopeter44]

1 hour ago, Baytree said:

Would anyone care to comment on advice from the Honest John writers that air-con systems are designed to be left on full time?

That's what I have learnt after driving for many years with cars with aircon, If you don't use regularly you'll find you will have to recharge the gas more often, this was the case with the Clio III I had. My previous 208, prior to the Yaris, it was always on.

With the Yaris, I leave the aircon in "Econ" mode in cooler weather, and only for very short trips, less than 2km, do I turn it off. Even then, I don't think I gain very much. At normal driving speeds, in warmer weather, it is, IMO, better to use AC than have the car windows open.

[FROSTYBALLS]

As regards the warranty claim rejection, air con often has a limited, shorter warranty.

[Guest]

For the comparitively small increase in fuel consumption, I prefer comfort. As Frosty posts, "conditioning" is an important aspect. It's purpose is to not only cool the air, but de-humidify it.

I leave my climate control on all year.

Even with fuel prices as they are it must be more cost effective than having to re-gas more often or even replace components though lack of use?

[Cyker]

I used to use it to slow the car down more in my Mk1 D4D  

It basically didn't work in the Mk2 - I suspect the previous owner never used it and the whole system just corroded to death (It is very important that no moisture gets into the system as it reacts with the AC gas to form an acid, which is what I suspect happened judging by how completely shagged the whole system was...)

In the Mk4 I just leave it on all the time since it's a climate control system anyway!

 

[Trewithy]

+1 for using it all the time.

[MikeSh]

2 hours ago, Baytree said:

Would anyone care to comment on advice from the Honest John writers that air-con systems are designed to be left on full time?

Bear in mind that just because the switch/light is on doesn't mean the compressor is operating, it just means that you are allowing it to run on demand. In cool weather it won't run much and will usually lockout near freezing temperatures.

I tend to turn my entire vent system off at home to reduce the chance of the engine being started unnecessarily (it's a hybrid) while getting the car in and out of the garage. Otherwise it's on unless I have the windows open - sometimes that's just nice when pootling about locally at 30mph or less.

 

[TonyHSD]

Air con in Toyota hybrids drains rapidly the hybrid Battery and does affect fuel consumption in certain conditions, particularly town driving.
When temperatures are over 20C° during the summer season best to use air con as the cooler air in the cabin is also used to cool down the hybrid Battery which is located under the rear seat and it’s air cooled only.
In cold winter days heating should also be used with hvac setting around 20C° or above to help maintain optimum temperature of the hybrid Battery and best comfort in the cabin.
Modern air conditioning systems does not need to be run all the time to maintain longevity, this is a myth only, therefore having AC permanently ON it’s not necessary. Leaving switched AC ON permanently can create and lock more moisture in the cabin in certain driving conditions, therefore it’s down to personal use and preferences whether to keep it always ON or switch ON and OFF when needed.
I personally prefer to turn AC ON only when I need and keep it OFF when not, sometimes during winter season my AC stays off for long periods of time 3-5 or more months, and there are no problems at all in the spring when I use for a first time after a long break. 
Two important things to maintain healthy hvac (heating, ventilation and air conditioning) :

1. Keep fan always ON at desired speeds 

2. Change your cabin filter annually or every 10k miles as opposite to what manufacturer recommended 20k miles or two years for example . 
👍

[Big_D]

My Aircon is on all the time, winter, and summer, for the same reasons @FROSTYBALLS stated. I am cool in summer and have no issues with fogging windows in winter

As @Stopeter44 says, if you don't use regularly you'll find you will have to recharge the gas more often

 

Although fuel costs are a factor right now, I bought my C-HR because I liked the car, not because it was fuel efficient. As a bonus, I got an amazing efficient Hybrid which I love.

 

[Saxmaniac]

I use Aircon sparingly being a tightwad, but always make a point of running it for a short time nearly every journey to keep oil circulating and prevent leakage. Incidentally, how many people look at the condenser? It's positioned to catch all the debris and if restricted will cause pressure to rise, compressor to work harder and probably shorten it's life 

[Baytree]

Thanks for all the replies! In our diesel VW, the difference could be 7mpg on the computer over a long journey. Looking forward to testing off vs. on with the Cross if it ever arrives. Still not seen one on the wild yet, either locally or on several trips to East Anglia. 

[TonyHSD]

3 hours ago, Baytree said:

Thanks for all the replies! In our diesel VW, the difference could be 7mpg on the computer over a long journey. Looking forward to testing off vs. on with the Cross if it ever arrives. Still not seen one on the wild yet, either locally or on several trips to East Anglia. 

On Toyota hybrids AC ON only affects fuel consumption when driving in town because Air con is run by the hybrid Battery and in hot days it does drains the Battery a lot and the car switches to petrol power a lot more. It is advisable by Toyota to use AC when hot outside and keep the saloon at room temperature as hybrid Battery is air cooled by the cabin air., therefore in summer ac on and in winter heating on are good practices. 👍