There are many threads about the issue here. In short, try to keep them away from the dust if you can. Does your room seal, or is the house open plan? If the room seals, then the solution is easy - but beware of forced-air climate systems as these will just blow the air straight into the room.
If the house is open plan, then obviously take steps to protect them - don't open doors in windy or dry conditions for instance. You can certainly cover them (plastic rubbish bags are fantastic for that purpose), and be sure to vacuum them regularly (once a month - instructions here if you search) so dust doesn't build up.
If they stay clean (like, hospital clean) then yes, they will last near enough to forever. It's just that will be unlikely. But with a bit of care, regular vacuuming then they will almost certainly see you out.