Hydoponics in a cold house

The catgrass is almost ready for the 3 kitties to consume. They can see it growing in the baby greenhouse. So, now I'm going to try and grow lettuce...a cool season crop...in a borrowed aeroponic system. The aerogarden baths the roots with water from the top of the root system still letting them get plenty of oxygen. It will be an interesting experiment. My only problem?!?!?!? Can I find a place where the cats will take little interest in them and warm enough to grow lettuce. The kitchen should be the best place for this experiment, but the temp drops down to 50 at night. It should not be too bad for the lettuce...we shall see.