Car Air Conditioning.

Mindful of the recommendations to give the aircon a run even in the winter I pushed the button today. It got me wondering (as I was doing 70mph) - is it kinder to the system to switch it on at tickover - or even before starting the car ? After all, it is a clutch. I suppose I am being a bit anal - but what is the view?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"DerbyBorn" wrote in message

I just leave it on all the time.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


It slows me down!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

<Jezza mode>
MORE POWER!!
</Jezza mode>
Tim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 09/01/16 17:37, Tim+ wrote:

I thought Labour party politics were off limits.....

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The clutch cycles the compressor on and off when running anyway.
--
*Never underestimate the power of very stupid people in large groups *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 09 Jan 2016 13:05:50 GMT

I would have thought that it would be easier on the engine and starting system to leave it off until the engine is running. But it might be delayed by the ECU or other controls anyway, I don't know. Mine ran out of refrigerant years ago, so it doesn't matter.
--
Davey.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I think it's normally an electromagnetic "clutch": the switch turns on an electromagnet on the engine plate of the clutch which attracts the air-con compressor plate, so there's probably no actual friction between pads and plate as the drive is taken up. Still maybe marginally kinder to turn it on before starting the engine.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 09/01/16 13:13, NY wrote:

Except that I am fairly sure its wont actually activate until the engine is running these days
--
You can get much farther with a kind word and a gun than you can with a
kind word alone.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
DerbyBorn wrote:

There is a good group for cars - uk.rec.cars.maintenance . It's a bit quiet, but the specialist advice available is excellent.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 09 Jan 2016 13:17:54 +0000, DanSMacAbre wrote:

Many of the people there are here, too.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
DerbyBorn presented the following explanation :

Mine defaults to enabled all of the time anyway, a climate system. The compressor clutch will be constantly engaging and disengaging - so it is designed for that. In winter it dries the moisture from the air flow too, so I just leave it to look after itself.
The old advice was to run it regularly anyway, to help keep the seals lubricated, but I understand that is no longer the case.
--
Regards,
Harry (M1BYT) (L)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 09/01/2016 13:17, Harry Bloomfield wrote:

Fine, but I always thought that is=t had big impact on fuel efficiency.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I tend to use mine as and when it is necessary, and turn it off (for fuel efficiency reasons) when it's not needed. I use it in winter to dry the air that is demisting the screen, but I turn it off once it's done the job because my car heater doesn't get hot enough to overcome the cooling of the aircon, so the air that's trying to keep the car warm never gets hotter than tepid with it on.
I hadn't realised that the clutch was constantly being cycled on a thermostat when it's on: I assumed that the compressor was permanently on when the button was pressed which is why the air gets so damn cold. Maybe it's only cycled if you have climate control.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 09 Jan 2016 13:48:41 +0000, NY wrote:

Is your thermostat knackered? Getting warm, dry air should be a doddle.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Well without aircon turned on, and with heater temp set to hot, the air coming from the heater is very hot, so maybe the aircon has too much chilling effect. With no heater (temp on cold), the aircon quickly produces condensation on the outside of the screen where moisture from the air outside condenses!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Certainly not in either of the Skoda Octavia's I've had. Plus they demist the passenger side first. The last few years I have always had to sit waiting for the screen to clear, then at about 6.50 each morning as I drove to the paper shop, I'd regularly see another Octavia coming in the other direction with the driver frantically wiping the screen with a cloth.
According to the annual postings on a Skoda forum, others have fitted absorbent dehumidifier packs and found they help.
--
Bill

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 09/01/16 13:48, NY wrote:

Nope.Its like the thermostat on a boiler: Once the circulating fluid is at the right temp it cuts out, even though that fluid is being pumped around a heat echanger
My jag XKs all had (massive) permanent climate control and the WHUMP of the pump cutting in at tickover practically stalled the engine - a V8 can tick over at pretty low revs.
--
You can get much farther with a kind word and a gun than you can with a
kind word alone.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Saturday, 9 January 2016 14:08:01 UTC, NY wrote:

The evaporator freezes up if the clutch doesn't periodically disengage.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 10 Jan 2016 14:24:32 -0800 (PST)

Yes, it should have a dedicated thermostat for that purpose. That is, in the immortal words of 1066 and All That, "A Bad Thing".
--
Davey.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.