Ale and Lager fermintation in the same chest freezer

I have access to a large commercial chest freezer. I would like to use it for both ale fermintation and lagering. I'm trying to work through my options. One would be to divide the freezer into 2 compartments separated by insulation and set the overall temp at lagering levels then use a temp cotroller and a heat source to raise the temp in the ale side - this should work but would be very inneficient. My other thought was to build a fermintation chamber and put a collar on the freezer, then build a pvc duct system with fans to move air from the freezer (lagering chest) to the fermintation chamber. This will be in my basement so temps are usually below 75 so i don't need to lower the temp much for ales.
Anybody have any idea or thoughts on which would be the best option?

Well this doesn't help but just a smart alec comment. I am fermenting both a ale and lager in the same fridge right now. using WLP810 CC beer yeast and US-05. The fridge is averaging 60F.

As far as your scenario, You could keep your freezer at 50F and put on a warming help to the ale to keep it a little warmer or shelter it somehow so it would not get all the coolness and stick the temp probe close to the lager.

I've been looking at this for a while, It is a 115v heating pad you can wrap around your carboy. you would need to get a two stage Ranco controller that controls two temps, or some thing like that where you control the Freezer chest to hold lager temps with one setting, and then with the second setting the heating pad warms the ale to the proper temp.

If you wanted you could add a layer of water heater wrap around the carboy with the heating pad, so the freezer would not have to work so hard...

I heard about this same method on The Jamil Show from The Brewing Network. I've seen some youtube videos of people doing this exact thing (unsure of their results).

I would do the duct thing, and wire the fan to a temp controller. When the temp in the ale chamber went above the desired temp, the fan kicks on, blowing cold air into the chamber, when the temp is back where it should be, the fan turns off,untill the next time.

I think the duct idea is the best idea too. Once you do it I'd love to see a picture or two

I just put together a similiar setup, I have a chest freezer that I've converted to a kegerator which also cools a foam fermenting chamber. I have the fermenting chamber attached to the chest freezer by ducts and a fan circulating air when the temp gets too high. Everything is controlled by a johnson controller and its working amazing!

Ewalk... any way to get some pics posted of your work so we can see how this was done? I'm sure the OP would love to get his hands on some pics.

Ewalk, I would love to see some pics of your keezer/fermentation chamber cooling system thing-a-ma-jig. You got any?