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New P85D owner: Is my HVAC working ok or does it need service?

Discussion in 'Model S: User Interface' started by gordo, Mar 9, 2015.

  1. gordo

    gordo Member

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    Jan 16, 2015
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    Location:
    CA
    So I've had my P85D for 3 days now and twice I've had the HVAC system act somewhat strangely. The latest incident was this evening...

    Let me start out by saying that I can confirm 100% that I'm NOT in Range mode and running firmware 167.

    Before my commute home today, the iPhone app said my car interior was at 101 degrees F after sitting in the sun all day. When i got to the car at 5:30pm, it was indeed very hot inside (felt around 100F), but by that time, it was 67F outside (according to the car itself). I figured that if I simply set everything in the climate settings to AUTO, the car would quickly pull in air from the outside to cool it down quickly. Well, I set the temp to 80 degrees synced on both sides and started the commute home. I could have rolled down the windows, but I was curious to see what the system would do if I just let it sort things out by itself. Turns out, it spent the better part of the first 5 minutes with the climate fan at probably it's lowest setting, puffing slightly cool air and having virtually no impact on the interior temp. I then pulled the temp down to 75F. Virtually no difference. I had to pull the temp down below 70F to get it to do anything at all and finally on LO, it started to blast cold air.

    So I guess question is, am I using it wrong (i.e. should I simply avoid trying to use AUTO?), or is there potentially something wrong with my car's HVAC? i assume if there is a problem, it's software related, since the inside and outside temps seemed to read accurately and the system clearly does work very well when settings are pushed to the limit.
     
  2. DrComputer

    DrComputer Member

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    If you search you will find many threads about the poor logic in the HVAC system. The consensus is that you need to set the desired temperature about 5 degrees cooler than you would in any other car. So if you would normally be comfortable at 74 in say a Lexus, you'd want to set the Model S to 69 to achieve the same feel.
     
  3. gordo

    gordo Member

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    OK, I guess I'll just have to get used to it. Funny though that if the external and internal thermometers are reasonably accurate why the HVAC logic would be so difficult to program properly after 3 years of software updates...
     
  4. DrComputer

    DrComputer Member

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    I think most would agree with you, but I've just gotten used to setting the temperature at 69 on warm days and 67 on colder days. I'm my former Lexus you could just leave it at 75 and it would always feel right. Maybe Tesla will fix the HVAC logic and temperature set points at some point...but I'm not holding my breath.
     
  5. Andyw2100

    Andyw2100 Well-Known Member

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    Did you notice if, when the HVAC was not really cooling the car well on AUTO, it was recirculating the air inside the vehicle, or pulling air in from outside? There are symbols to indicate that. Based on how little cooling was happening, it sounds like it may have been recirculating the air inside your car until you eventually got it to really do anything, at which point it may have switched to bringing in air from outside.
     
  6. Alysashley79

    Alysashley79 Member

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    Seattle, WA
    It sounds normal. What I've found in warmer days when I want it to cool the car quickly I bump it to LO and it cools down and then set it to my desired setting. Generally 80 degrees is still quite hot and is considered heat not cooling so that would be my guess on why it blew so slowly out.
     

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