If a person really wants a smoke alarm, please at least get one made for BARNS. They are significantly more expensive, but have some reasonable chance of *working* in a high-dust environment. Household ones simply DON'T work there. It is not an issue of 'keeping them clean' and all that, they just do not get along well with dust. They are notoriously USELESS in barns (lots of false alarms, but tendency to ignore actual fire).
Also those in northern climates will need a hardwired (house current powered) alarm unless you want it to simply not work during the winter. Again, it is not really a matter of 'replacing the batteries frequently' or anything like that -- at like -20 F, AA batteries just *don't* work.
Really, this is not theory or wishful thinking speaking here, this is 35+ years of working in horse barns will a variety of smoke-alarm systems.
Pat