Thanks for the data.

 

Could anyone point out the intake vent to the HVTB to draw in the cabin air? From my understanding, the high voltage battery receives air from the outside vent (driver side rear window) using the fan. I did not know that it also takes cabin air. Can someone tell me where the vent is so I do not forget to not block it.

Thanks!

 

This is only on the 2010-2012 cars. '04-'09 is different. The earlier models draw outdoor air through a vent/duct that's built into the rear window frame on the rear driver's side window. On those cars, there is also an access panel on the inside driver's rear cargo panel for the little air filter that is built into the system to keep the outside air clean, so the battery doesn't suck in dust/debris, etc.

Mine is a 2010, so everything's different. The outside air intake is gone. There's no longer any AC plumbing/evaporator in the rear cargo panel. Instead, there's just a vent that pulls in cabin air. Ford mentions the vent in the manual but don't show a picture. Photo is attached. You can't see it well in this picture but right above the vent the words "DO NOT BLOCK VENT" are molded into the panel. I am not sure what the larger vent up above it does, but the one I outlined in RED is definitely for the HVTB. Nice how it's located about 6 inches off the floor of the compartment, so anything big back there will block it.

Does anyone know what the larger vent above it is for?



High Voltage Battery Cooling Vent 2010 Ford Escape Hybrid Limited Driver's Side Cargo Compartment


On the passenger side, my car has two grilles molded into the panel, large and small, which I think is a subwoofer and a tweeter for the premium sound system.



PASSENGER SIDE CARGO COMPARTMENT PANEL 2010 FORD ESCAPE HYBRID LIMITED PREMIUM SOUND SYSTEM

Hope this helps!

UPDATE: I put the climate control on MAX A/C and turned the fans all the way up. I didn't feel anything coming out of the mystery vent labeled ????? in my first photo, so it doesn't appear to blow cold air from the A/C system. Don't know what it does.

 

Thanks for the pics!

Huh! I didnt know that about 2010 and up. My 2009 has vent from outside like you mentioned and the filter inside the rear cargo driver side.

Where is the exhaust if there is no outside vent for 2010 and up for the HVTB battery? could that unlabeled vent the exhaust?

 

Unknown. I ran the MAX A/C and didn't feel anything, it was just turning the key for a minute or two and the car wasn't running. It seems strange to me that Ford would bring "cool" air in through one vent and then push "warner" air right back out through a bigger vent directly above it. But who knows at this point? Engineers can convince themselves of a lot of silly things if they illustrate them with pretty arrows on a diagram and the beancounters in management are telling them to save money, or else.

 

Heat rises so if its a vent to help equalize battery temp to ambient, its a simple and elegant solution not too mention low cost ans maintenance free. I thought the upper vent was there to allow airflow to the rear body cavity to reduce longer term corrosion and mold but I didn't give it much thought.

 

Heat doesn't rise. Heat flows from warm to cold. Lower density air rises. Warm air is lower density than cold air. Those physical phenomena have no meaningful function in the context of the HV battery cooling. Natural convection due to "heat rising" is a very weak influence in cooling. It would also be incredibly impractical to shed battery heat back into the compartment from which it is drawn. A warm battery with a cooling system operating in the way you imagine would make the back seat uncomfortably warm. No one would want to sit on that side, and the battery cooling would be severely compromised.

If I had to guess, that vent exists to feed a bypass intake that may exist in the event of the main intake being blocked. All models of the Prius had alternate means of air intake, albeit reduced, if the main inlet was blocked.

It may also be for the aeration of the rear body cavity as you describe.

If anyone wants to pull the side panel and take pictures, that would be fantastical.

 

S Keith does a very credible job of describing the thermodynamics involved. My description was more blockheaded but I basically agree: it would be very strange to me from an engineering point of view if Ford decided to draw cooling air from the passenger compartment through a vent, push it through the battery and then exhaust that hot air back into the same compartment they drew it from, when they could push it outside somehow, relatively easily. Since the cabin A/C is the only thing that cools the air and there's no rear A/C evaporator, why on Earth would they take something they've already cooled once and vent it back inside and have to cool it again? I haven't taken the panel apart or looked at how the battery fans vent their exhaust, but I would be surprised indeed if that air goes back into the passenger compartment. It wouldn't be the first time engineers have done something like that, but I'm not that jaded yet.