[NYvolt21]

I was driving this evening with the fan only mode in the hvac selection. For the first 15 minutes of the drive it was fan half way speed just as usual only drawing 3%, then it shoot up to 80%, heater turned on and warm air started to come out, the temp was set to 70f. Is this normal behavior? I thought the FAN only was supposed to keep resistance heat off since it's the biggest energy hog. It's a late model 2012 Volt.

 

[Neromanceres]

It sounds like you have auto defog turned on. The Volt has a humidity sensor and will turn on the HVAC to de-humidify the air to keep your windows clear. It's set very conservatively and can be quite aggressive. It can be turned off in the user options.

 

[NYvolt21]

It sounds like you have auto defog turned on. The Volt has a humidity sensor and will turn on the HVAC to de-humidify the air to keep your windows clear. It's set very conservatively and can be quite aggressive. It can be turned off in the user options.

Ahh. ok, good to know. Indeed, I do have the auto defog feature turned on, I thought it would only trigger the more efficient AC compressor to defog.

Thanks

 

[Neromanceres]

Ahh. ok, good to know. Indeed, I do have the auto defog feature turned on, I thought it would only trigger the more efficient AC compressor to defog.

Thanks

Correct. The auto defog can actually trigger both the heat and the AC compressor at the same time depending on conditions. So it can use a lot of power.

 

[ClarksonCote]

Correct. The auto defog can actually trigger both the heat and the AC compressor at the same time depending on conditions. So it can use a lot of power.

That said, keep an eye on it still. If it's still happening, you may need a firmware update. There were some odd behaviors with HVAC from time to time with the Gen 1 Volt.