A device for spraying an inner surface of a wall of an enclosure with a fluid is disclosed. The device includes a reservoir for the fluid, a nozzle assembly through which the fluid can be sprayed on the inner surface of the wall of the enclosure, a fluid conduit in fluid communication with the reservoir and the nozzle, a pump for delivering fluid from the reservoir through the fluid conduit and to the nozzle when the pump assembly is activated, and a controller in electrical communication with the pump wherein the controller executes a stored program to activate and deactivate the pump. The nozzle assembly includes a nozzle which directs the fluid in a fluid path, and the nozzle assembly further includes a deflection shield that is dimensioned to contact and redirect fluid in the fluid path, and the nozzle assembly further includes mounting structure for attaching the nozzle near the inner surface of the wall of the enclosure. The flow off of the deflector shield is laminar.