temperature control help!!!

I have project in which i have to create a soultion which will mantain the temperature of a living space with a volume of 400m3 between 25-30 degrees centigrade.

I can use the following components

lm35 TEMPERATURE SENSOR
lm358 Operational amplifer
3 X lm311 compararators
74ls32 Quad OR Gate
74ls04 Hew NOT Gate
2 X 12 Volt Relays

If anybody could design us a circuit diagram this would be great!!! many thanks my friends

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Dave