14000 btu is just over a ton of cooling not much .I would try this just to see if it would work get a used 2 ton (24000 btu) window air conditioner. Take the cooling coil out of it. Extend the suction line and liquid line . Recharge it .And drop the cooling coil in the coolant. You would have to get someone that does refregeration, it shoud not cost
If that works I would go to a moible home supply store and get a 2 ton ac split system that comes pre charged with freon put the condenser out side the cooling coil in the tank.It would cost around $1500.