Mach-E Forum | Ford Mustang Mach-E Forum and News banner

1 - 10 of 10 Posts

·
Registered
Currently: 2021 Grabber Blue First Edition Mach E AWD ER ; Previously: 2009 Ford Focus.
Joined
·
193 Posts
Hopefully the heated seats still work
 

·
Super Moderator
Joined
·
2,705 Posts
Did Tesla remove the resistance heater, and only rely on the heat-pump? Does anyone know if it has both systems?

If it has both systems still, It may be some sort of sensor/valve issue.
 

·
Registered
Joined
·
231 Posts
The small number of Tesla Motors Club Forum members reporting problem with their heating had it fixed with a firmware update. It is heat pump only, and the octovalve uses the heat pump for multiple heating/cooling needs of the car. An interesting example is using heat generated by battery cooling can supplement cabin heating.
 

·
Registered
Joined
·
1,147 Posts
Discussion Starter · #5 · (Edited)
The small number of Tesla Motors Club Forum members reporting problem with their heating had it fixed with a firmware update. It is heat pump only, and the octovalve uses the heat pump for multiple heating/cooling needs of the car. An interesting example is using heat generated by battery cooling can supplement cabin heating.
What is the sweet spot where the battery requires cooling but cabin requires heat? Doubt the battery packs require any cooling when it's 0*F... maybe after driving a 100 miles?
 

·
Super Moderator
Joined
·
2,705 Posts
What is the sweet spot where the battery requires cooling but cabin requires heat? Doubt the battery packs require any cooling when it's 0*F... maybe after driving a 100 miles?
The heat pump is only good at moderately cold temps. They lose effectiveness as temperatures fall below 40°F, and are useless at freezing temperatures. So you save the most energy when heating above 40°F.
 

·
Registered
Joined
·
231 Posts
What is the sweet spot where the battery requires cooling but cabin requires heat? Doubt the battery packs require any cooling when it's 0*F... maybe after driving a 100 miles?
Just an example, the octovalve directs heat and cooling from various sources to where it is called for - outside air, inside air, either side of the heat pump cycle, motor and battery heat, etc.

BTW, heat pumps have advanced in efficiency to the point where they provide heat in much colder temperatures than before. Have you seen the heat pump installations in New England homes on "This Old House"?
 

·
Registered
Joined
·
1,147 Posts
Discussion Starter · #9 ·
Just an example, the octovalve directs heat and cooling from various sources to where it is called for - outside air, inside air, either side of the heat pump cycle, motor and battery heat, etc.

BTW, heat pumps have advanced in efficiency to the point where they provide heat in much colder temperatures than before. Have you seen the heat pump installations in New England homes on "This Old House"?
I live in an old house in the Northeast and have multiple heat pumps (HVAC and hot water) so I am familiar with them. I'll be adding a 2 zone mini-split in my new addition. Yes they have gotten better, some modern heat pumps specify effective operation to -20*F but let's just say it's mostly specsmanship...

But my question was... what is the sweet spot temp range where the battery needs cooling while the cabin needs heating? Does anyone know? Has anyone attempted to estimate COP (for Heating and Cooling)?
 

·
Super Moderator
Joined
·
2,705 Posts
Just an example, the octovalve directs heat and cooling from various sources to where it is called for - outside air, inside air, either side of the heat pump cycle, motor and battery heat, etc.

BTW, heat pumps have advanced in efficiency to the point where they provide heat in much colder temperatures than before. Have you seen the heat pump installations in New England homes on "This Old House"?
Home systems are a different animal altogether.

The problem with EVs are, there is nothing generating enough heat to compensate for the cold.

Eventually the system will reach a point where there is nothing to exchange without sacrificing battery life. This happens at just above freezing. The OctoValve will take whatever heat is generated from the motors and feed it to the battery. The heat pump will stop supplying heat to the cabin and the normal cabin heater will kick in.
 
1 - 10 of 10 Posts
Top