Ford Develops New HVAC System w/ Roof-Mounted AC Unit

[rabbit33]

Originally Posted by KO Stradivarius

[/b]

That's the point. The article explains that the dash/cowl (firewall) area is getting too full of other components, so that's one of the reasons:
....

Yeah, we wouldn't want to consider getting rid of some of THAT crap, would we?

[KO Stradivarius]

Vehicles are packaging nightmares (finding places to fit things). You only have a limited amount of space to fit everything in between the exterior surface and the occupants, wheelbase, etc, and still be able to assemble and service the parts while still enabling the vehicle to function better than your competition. Endless requirements and attributes are traded off in order to meet them at the cost where you can make a profit. You simply just cannot stop innovating and discovering better ways of doing things. Especially with today's hyper-competitive environment in the auto business. Engineers deserve a large amount of respect for the things they do.

People like to complain about it, like "Unnecessary complication" or "Why did they change this or that?", but car makers don't have much choice. Some clichés that fit are "Necessity is the mother of invention" (Plato), "Don't make perfect the enemy of good" (French proverb), and “If You Always Do What You've Always Done, You'll Always Get What You've Always Got.” (Henry Ford).

[Hemlock140]

We have the overhead, roof mounted AC in our travel trailer. It actually cold the space faster because cold air sinks, and the cold air is coming out with more force than dash vents. The problem is that the compressor and motor are so close to the vents, so there is a loud noise. Unless Ford has figured out a way to silence it, that's not something I would want. The other problem is clearance. Even now my F150 4x4 will not fit in many city parking garages, where the clearance is less than 7'.

[Rsaw7854]

Interesting idea, but I don't see a single Ford Climate Control Engineer's name on the patent that would lend creditability to the idea is anywhere near production ready. There are major hurdles to over come before this would be feasible;

1) What happened to the heater portion of the HVAC system (H= heat, V= ventilation, & A/C). You want to heat the feet and legs. Heat rises, just the opposite of cold air. How do you clear (defrost) the windshield and side windows with this system? Electrically heated windshields and side windows? They consume large amounts of energy. They are very expensive and insurance companies hate them due to replacement cost. Then there are the fine wires electric windshields where fine wires are embedded in the windshield causing on coming headlight to flare at night. Can be very distracting.
.
2) NVH, fans and electric compressor are not silent and you just moved the noise source right by the occupants ears in a very quiet vehicle.
.
3) Have you ever looked at the size of the vehicles HVAC components? They are not small and for good reason. Vehicle A/C systems are in the range of 1.5 to 4 tons of A/C capacity. Before you say how can that be, my house has X tons and it is much larger interior space. Why so much capacity? Its the rapid cool down that requires that much capacity for such a small space compared to a house. You are cooling an interior that can reach 200+F with a large thermal mass and needs to be cool to ~72F in a short time. A house stays in a relative narrow temperature range and the A/C turns on every ~20 minutes all day.

[RocketDawg]

There might be some mileage efficiency issues because of aerodynamics.