Furnace humidifier

Claim 2

A humidifier unit for a warm air-heating system of the type including a furnace to heat air for supply to a living space, air passage means for circulation of air through said furnace to said living space including a furnace plenum chamber, heating means in the furnace for heating air in the plenum chamber, an electrically driven blower for propelling air through the plenum chamber and air passage means, a first electrical furnace control circuit including a room thermostat responsive to temperature in the living space for operatinG the heating means, and a second electrical furnace control circuit including a blower control bonnet switch responsive to the temperature in said plenum chamber having a selected blower cut-on temperature and a lower blower cutoff temperature for operating the blower during the period the temperature in the plenum chamber is above the cut-on and cutoff temperature levels; the humidifier system comprising a water spray nozzle to be located in said air passage means for discharging a fine mist spray therein during circulation of air therethrough for humidifying the circulating air, a supply valve controlling water supply to said spray nozzle, a solenoid coil for opening and closing said supply valve, a manually variable temperature-sensitive switch for sensing the air temperature in the region of said air passage means occupied by said spray nozzle and adjustable to a range of cut-on and cutoff temperature settings near and above the cut-on and cutoff temperature levels of conventional bonnet switches for furnaces, a sail switch having a sail member to be located in said air passage means activated by air currents flowing therethrough when said blower is operating to close an electrical circuit through said sail switch, and electrical circuit means connecting said sail switch and said temperature-sensitive switch in series circuit relation with said solenoid coil and with an electrical supply source for opening said supply valve only when said sail switch and said temperature-sensitive switch are in closed circuit condition.

Claim 3

A warm air-heating system as defined in claim 1, wherein said air passage means includes a hot air supply duct directly adjoining said furnace for passage of heated air from the furnace and a cool air return duct connected to said furnace for return of cool air to said blower, said temperature-sensitive switch being mounted on said hot air supply duct adjacent said furnace for sensing the temperature of the air immediately upon entering said hot air supply duct from said furnace, and said sail switch being mounted on said cold air return duct with the sail located within said duct to respond to airflow therein.

Claim 4

A warm air-heating system as defined in claim 1, wherein said air passage means includes a hot air supply duct directly adjoining said furnace for passage of heated air from the furnace and a cool air return duct connected to said furnace for return of cool air to said blower, said temperature-sensitive switch and spray nozzle being mounted on said hot air supply duct adjacent said furnace for sensing the temperature of the air immediately upon entering said hot air supply duct from said furnace and spraying water mist into the air at said location, and said sail switch being mounted on said cold air return duct with the sail located within said duct to respond to airflow therein.

Claim 5

A system as defined in claim 2 wherein said sail switch includes a humidistat which is adjustable to selected humidity levels and completes an electrical circuit therethrough only when the sail is activated by airflow through said return duct when the blower is operating and the humidity concurrently does not exceed a selected level.

Claim 6

A system as defined in claim 3 wherein said sail switch includes a humidistat which is adjustable to selected humidity levels and completes an electrical circuit therethrough only when the sail is activated by airflow through said return duct when the blower is operating and the humidity concurrently does not exceed a selected level.

Claim 7

A warm air-heating system of the type comprising a furnace to heat air for supply to a living space, air passage means for circulation of air through said furnace to said living space including a furnace plenum chamber, heating means in the furnace for heating air in the plenum chamber, an electrically driven blower for propelling air through the plenum chamber and air passage means, a first electrical furnace control circuit including a room thermostat responsive to temperature in The living space for operating the heating means for heating the air during the period the thermostat occupies a demand condition, a second electrical furnace control circuit including a blower control switch communicating with said plenum chamber and responsive to the air temperature therein having a selected blower cut-on temperature and a lower blower cutoff temperature for operating the blower during the period the temperature in the plenum chamber is above the cut-on and cutoff temperature levels, a humidifier water spray nozzle located in said air passage means for discharging fine mist spray therein during circulation of air therethrough for humidifying the circulating air, a water supply conduit having a solenoid valve controlling water supply to said spray nozzle, a solenoid coil for opening and closing said valve, a manually variable temperature-sensitive switch for sensing the air temperature in the region of said air passage means occupied by said spray nozzle and adjustable to a range of cut-on and cutoff temperature settings near and above the cut-on and cutoff temperature levels of conventional bonnet switches for furnaces, a sail switch having a sail member located in said air passage means activated by air currents flowing therethrough when said furnace blower is operating to close an electrical circuit through said sail switch, and electrical circuit means connecting said sail switch and said temperature-sensitive switch in series circuit relation with said solenoid coil and with an electrical supply source for opening said valve means only when said sail switch and said temperature-sensitive switch are in closed circuit condition.

Claim 8

A warm air-heating system of the type comprising a furnace to heat air for supply to a living space, air passage means for circulation of air through said furnace to said living space including a furnace plenum chamber, heating means in the furnace for heating air in the plenum chamber, an electrically driven blower for propelling air through the plenum chamber and air passage means, a first electrical furnace control circuit including a room thermostat responsive to temperature in The living space for operating the heating means for heating the air during the period the thermostat occupies a demand condition, a second electrical furnace control circuit including a blower control switch communicating with said plenum chamber and responsive to the air temperature therein having a selected blower cut-on temperature and a lower blower cutoff temperature for operating the blower during the period the temperature in the plenum chamber is above the cut-on and cutoff temperature levels, a humidifier water spray nozzle located in said air passage means for discharging fine mist spray therein during circulation of air therethrough for humidifying the circulating air, a water supply conduit having a solenoid valve controlling water supply to said spray nozzle, a solenoid coil for opening and closing said valve, a manually variable temperature-sensitive switch for sensing the air temperature in the region of said air passage means occupied by said spray nozzle and adjustable to a range of cut-on and cutoff temperature settings near and above the cut-on and cutoff temperature levels of conventional bonnet switches for furnaces, a sail switch having a sail member located in said air passage means activated by air currents flowing therethrough when said furnace blower is operating to close an electrical circuit through said sail switch, and electrical circuit means connecting said sail switch and said temperature-sensitive switch in series circuit relation with said solenoid coil and with an electrical supply source for opening said valve means only when said sail switch and said temperature-sensitive switch are in closed circuit condition.

Claim 9

A warm air-heating system as defined in claim 6, wherein said air passage means includes a hot air supply duct directly adjoining said furnace for passage of heated air from the furnace plenum chamber and a cool air return duct connected to said furnace for return of cool air to said blower, said temperature-sensitive switch and spray nozzle being supported by a housing mounted on said hot air supply duct adjacent said furnace with the spray nozzle and portions of the temperature-sensitive switch extending into the interior of the duct for sensing the temperature of the heated air immediately entering said hot air supply duct from said furnace and spraying water mist into the heated air at said location, and said sail switch being mounted on said cold air return duct with the sail located within said duct to respond to airflow therein.

Claim 10

A system as defined in claim 6 wherein said sail switch includes a humidistat which is adjustable to selected humidity levels and completes an electrical circuit therethrough only when the sail is activated by airflow through said air passage means when the blower is operating and the humidity concurrently does not exceed a selected level.

Claim 11

A system as defined in claim 7 wherein said sail switch includes a humidistat which is adjustable to selected humidity levels and completes an electrical circuit therethrough only when the sail is activated by airflow through said return duct when the blower is operating and the humidity concurrently does not exceed a selected level.