I don't think a Peltier system is used for the heating. The heating element seems to be a traditional resistive heater.
The "cool" mode MAY be a peliter, but I doubt it. When you turn on the cool mode, a fan pushes air out the ventilated sections of the seats. I've never felt the air coming out of the seat any cooler than the air in the car, so my guess is that its simply circulating air from the cabin (already air conditioned) to help keep your back cool. Also, no part of the seat that I've been able to feel underneath gets hot when using the ventilated mode. A peltier device uses electricity to make one area hot, and another one cold. Since there's no dumping of heat from underneath the seat, my guess is there's no peltier - just the fan.
The seats in our 2013 do in fact use a peltier device (this has been discussed in other threads) for heating and cooling. If I remember correctly the company supplying the seats was called Amerigon (and is now called Gentherm). I can't speak for other years, but that is what our vehicle has. When the seat coolers are on I can feel a gentle breeze of warm air on the backs of my calves so I can only assume that is where the waste heat is being dumped. I can't say it is all that warm (though definitely perceptible) but I wouldn't expect it to since the cooled air isn't all that cool.
Found a link!
Amerigon Climate Control Seat® (CCS®) System Selected as Option for 2013 Ford Flex
To quote:
NORTHVILLE, Mich., March 12, 2012 /PRNewswire/ -- Amerigon Incorporated (NASDAQ-GS: ARGN), a global developer and marketer of innovative thermal management technologies, announced today that its proprietary Climate Control Seat® (CCS®) system has been selected for the 2013 Ford Flex, a full-size crossover vehicle. The heated and cooled seat system is included in the luxury seating package for the front seats of the Limited model.
Amerigon President and Chief Executive Officer Daniel R. Coker said, "We are pleased to have our heated and cooled seat system included as part of the upgraded interior options in the 2013 Ford Flex, a popular crossover vehicle. Our longstanding relationship with Ford and its variety of superior vehicles has always been an important asset of Amerigon's."
Other vehicles from Ford that offer CCS include the
Ford Explorer, Ford Expedition, Ford Taurus, Ford F-150 Truck and Ford F-250 Truck.
About CCS
In the CCS system, which is built around Amerigon's highly-efficient,
solid-state thermoelectric device, air is forced through the heat pump and thermally conditioned in response to electronic switch input from the seat occupant. The conditioned air circulates by a specially designed fan through ducts in the seat cushion and seat back, resulting in a surface that can be heated or cooled. Each seat has individual electronic controls to adjust the level of heating or cooling. CCS substantially improves comfort compared with conventional air conditioners by focusing the cooling directly on the passenger through the seat, rather than waiting until ambient air cools the seat surface behind the passenger.
Amerigon is the largest supplier of TE systems for cars, with more than 6.5 million thermoelectric-based seat systems sold.