Rpm increases when a/c is turned on

[Naveed922]

hi, iv recently noticed that everytime i turn my ac on my rpm increases to 700-800, is this normal?
i didnt notice this happening before, just realised it today and you can hear the fan working harder, any clues?

 

[dm222]

What rpm do you have with it turned off?

 

[Legojon]

Yup, the engine has to work harder. Which is why people think it's economical to switch it off as it "saves petrol".

 

[Naveed922]

idles at around 5-600 & when i turn ac on goes between 700-1000, i havent noticed this before?

 

[dm222]

Mine is never lower thsn 700 but I would gess its normal as the ac needs more power from the engine.

 

[Naveed922]

i will try and upload picture at idle & then with ac on, i dont think its normal because havent seen it before

 

[Scrogg]

i dont think its normal because havent seen it before

It's normal. it's more obvious in warmer weather, which may be why you haven't noticed it before.

 

[martin j.]

The engine is powering a compressor so extra revs are required to compensate for the extra drag, and then of course the alternator starts up to power the fans, unfortunately the engine is not clever to merely raise the revs back to normal so can be a tad higher.

 

[ChriskiB]

My Ibiza does this when its cold and I put the blowers on warm and on full, it will also raise the RPM from 750/800 to just over 1000rpm if i'm sat at idle and I put the A/C on. Perfectly Normal nothing to worry about.