Surface cleaning apparatus

1. A surface cleaning apparatus for cleaning a surface, comprising:

a housing at least partially defining an air pathway;

a fluid delivery system having a supply tank provided with the housing for storing cleaning fluid and a fluid distributor for delivering the cleaning fluid from the supply tank to the surface;

a motor/fan assembly provided within the air pathway for generating an airflow through the air pathway wherein the motor/fan assembly transfers heat to air moving through the air pathway and removes heated air from the air pathway, the air pathway having an inlet upstream of the motor/fan assembly and an outlet downstream of the motor/fan assembly; and

a duct downstream of the motor/fan assembly and upstream of the outlet and having a section in heat exchange relationship with the supply tank, with the section of the duct having an undulating profile providing an increased surface area in heat exchange relationship with the supply tank to heat the supply of cleaning fluid in the supply tank by heat transfer from the heated air;

wherein the section of the duct having the undulating profile is at least partially formed by a side wall of the supply tank and an exterior wall of the housing.

2. The surface cleaning apparatus of claim 1 , wherein the side wall of the supply tank comprises the undulating profile.

3. The surface cleaning apparatus of claim 2 , wherein the undulating profile comprises a plurality of elongated channels formed in the side wall of the supply tank.

4. The surface cleaning apparatus of claim 2 , wherein the duct is further at least partially formed by a section extending interiorly though the housing.

5. The surface cleaning apparatus of claim 4 , wherein the duct further comprises an internal air guide which leads the heated air through at least one 180° turn.

6. The surface cleaning apparatus of claim 1 , wherein the air pathway comprises a motor-cooling air pathway, and the motor/fan assembly comprises a motor provided within the motor-cooling air pathway, between the inlet and outlet, for providing cooling air to the motor and for removing heated cooling air from the motor, and the duct is downstream of the motor.

7. The surface cleaning apparatus of claim 6 , wherein the motor is enclosed within a motor cover, and the motor cover includes at least one aperture for allowing cooling air to enter the motor cover and pass by the motor.

8. The surface cleaning apparatus of claim 6 and further comprising a fluid recovery system defining an extraction pathway for removing the delivered cleaning fluid and debris from the surface and having a recovery tank storing the recovered cleaning fluid and debris.

9. The surface cleaning apparatus of claim 8 , wherein the extraction pathway is fluidly isolated from the motor-cooling air pathway.

10. The surface cleaning apparatus of claim 8 , wherein the housing carries the fluid delivery system and the fluid recovery system.

11. The surface cleaning apparatus of claim 8 and further comprising a hand-held accessory tool in fluid communication with the supply tank, wherein the fluid distributor is provided on the hand-held accessory tool.

12. The surface cleaning apparatus of claim 11 , wherein the fluid recovery system comprises an extraction nozzle provided on the hand-held accessory tool in fluid communication with the recovery tank.

13. The surface cleaning apparatus of claim 8 , wherein the housing comprises a base and a partition extending upwardly from the base, and the supply and recovery tanks rest on the base and are separated by the partition.

14. The surface cleaning apparatus of claim 13 , wherein the partition comprises a carry handle at an upper portion thereof which facilitates carrying the surface cleaning apparatus.

15. The surface cleaning apparatus of claim 13 , wherein the inlet for the air pathway is provided in the partition.

16. The surface cleaning apparatus of claim 15 , wherein the outlet for the air pathway is provided in the base.

17. A surface cleaning apparatus for cleaning a surface, comprising:

a housing at least partially defining an air pathway;

a fluid delivery system having a supply tank provided with the housing for storing cleaning fluid and a fluid distributor for delivering the cleaning fluid from the supply tank to the surface;

a fluid recovery system defining an extraction pathway for removing the delivered cleaning fluid and debris from the surface and having a recovery tank storing the recovered cleaning fluid and debris;

a motor/fan assembly provided within the air pathway for generating an airflow through the air pathway wherein the motor/fan assembly transfers heat to air moving through the air pathway and removes heated air from the air pathway, the air pathway having an inlet upstream of the motor/fan assembly and an outlet downstream of the motor/fan assembly; and

a duct downstream of the motor/fan assembly and upstream of the outlet and having a section in heat exchange relationship with the supply tank, with the section of the duct having an undulating profile providing an increased surface area in heat exchange relationship with the supply tank to heat the supply of cleaning fluid in the supply tank by heat transfer from the heated air;

wherein the housing comprises a base and a partition extending upwardly from the base, and the supply and recovery tanks rest on the base and are separated by the partition;

wherein the partition comprises a carry handle at an upper portion thereof which facilitates carrying the surface cleaning apparatus.

18. A surface cleaning apparatus for cleaning a surface, comprising:

a housing at least partially defining an air pathway;

a fluid delivery system having a supply tank provided with the housing for storing cleaning fluid and a fluid distributor for delivering the cleaning fluid from the supply tank to the surface;

a fluid recovery system defining an extraction pathway for removing the delivered cleaning fluid and debris from the surface and having a recovery tank storing the recovered cleaning fluid and debris;

a motor/fan assembly provided within the air pathway for generating an airflow through the air pathway wherein the motor/fan assembly transfers heat to air moving through the air pathway and removes heated air from the air pathway, the air pathway having an inlet upstream of the motor/fan assembly and an outlet downstream of the motor/fan assembly; and

a duct downstream of the motor/fan assembly and upstream of the outlet and having a section in heat exchange relationship with the supply tank, with the section of the duct having an undulating profile providing an increased surface area in heat exchange relationship with the supply tank to heat the supply of cleaning fluid in the supply tank by heat transfer from the heated air;

wherein the housing comprises a base and a partition extending upwardly from the base, and the supply and recovery tanks rest on the base and are separated by the partition;

wherein the inlet for the air pathway is provided in the partition.