Smoke alarm going off all hours of the night?

My family and I have been living in an apartment for about 6 mo. There are a couple of small things wrong but, nothing major just annoying. But, my smoke alarm goes off randomly all the time. All hours of the night it just wake me up. I told my landlord, and he keeps saying he is going to get a new one. Today the manager and the maintenence guy came by, and the maintenence guy just kept saying "Yeah these are really just heat sensors" ok great, where is the heat. We almost started arguing about it but the landlord assured me he would get a new one and they left. I have replaced battery, sprayed with aerosol to get out potential bugs or dust, and they are not connected to other smoke alarms.