# US 2014/0197243 A1 · Hydronic air heater > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197243 A1 - Document ID: US20140197243A1 - Status: Published application - Kind: A1 - Application number: 14/153,287 - Filed: 2014-01-13 - Published: 2014-07-17 - Earliest claimed: 2013-01-15 - Assignees: Mestek, Inc. - Inventors: Kenneth W. Cohen - Web page: https://patentgrep.com/patent/US20140197243A1 ## CPC - F24H 6/00: Combined water and air heaters - F24D 3/00: Hot-water central heating systems (district heating systems F24D10/00; central heating systems using heat accumulated in storage masses F24D11/00) - F24D 5/00: Hot-air central heating systems (district heating systems F24D10/00; central heating systems using heat accumulated in storage masses F24D11/00; air conditioning F24F); Exhaust gas central heating systems - F24D 15/02: consisting of self-contained heating units, e.g. storage heaters - F24D 19/0097: {Casings or frame structures for hydraulic components} - F24D 19/1009: {for central heating} - F24H 9/2007: {for water heaters} - F24H 15/156: Reducing the quantity of energy consumed; Increasing efficiency - F24H 15/176: Improving or maintaining comfort of users - F24H 15/204: Temperature of the air before heating - F24H 15/208: Temperature of the air after heating - F24H 15/212: Temperature of the water - F24H 15/335: Control of pumps, e.g. on-off control (control of compressors of heat pumps F24H15/38) - F24H 15/35: Control of the speed of fans - F24H 15/36: of burners - Y02P 80/10: Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) - F24D: DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR (using steam or condensate extracted or exhausted from steam engine plants for heating purposes F01K17/02) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A hydronic air heater includes a frame assembly defining an enclosure, an inlet air damper formed in a wall of the enclosure and providing a means of ingress for ambient air, a closed heat transfer loop disposed within the enclosure, and a blower assembly disposed within the enclosure. The heat transfer loop includes a boiler for heating a fluid, a pump for circulating the fluid within the loop and a heating coil for receiving the heated fluid from the boiler. The blower assembly is configured to draw air into the enclosure through the inlet air damper and through the heating coil whereby heat from the fluid within the heating coil is transferred to the air. ## Claims ### Claim 1 A hydronic air heater, comprising: a frame assembly defining an enclosure; an inlet air damper formed in a wall of said enclosure and providing a means of ingress for ambient air; a closed heat transfer loop disposed within said enclosure, said heat transfer loop including a boiler for heating a fluid, a pump for circulating said fluid within said loop and a heating coil for receiving said heated fluid from said boiler; and a blower assembly disposed within said enclosure and being configured to draw air into said enclosure through said inlet air damper and through said heating coil whereby heat from said fluid within said heating coil is transferred to said air. ### Claim 2 (depends on 1) The hydronic air heater of claim 1, further comprising: a partition within said enclosure, said partition substantially isolating an upstream end of said enclosure from a downstream end of said enclosure, said downstream end of said enclosure housing heat-generating components including said boiler and said blower assembly; and a heat recovery tube extending from said downstream end to said upstream end and being configured to recover heat lost from said heat-generating components in said downstream end and to provide said lost heat to said heating coil in said upstream end. ### Claim 3 (depends on 1) The hydronic air heater of claim 1, wherein: said hydronic air heater is substantially hermetically sealed except for said inlet air damper. ### Claim 4 (depends on 1) The hydronic air heater of claim 1, wherein: said fluid is a water/glycol mixture. ### Claim 5 (depends on 1) The hydronic air heater of claim 1, further comprising: a variable frequency drive electrically connected to said blower assembly and being configured to control a speed of said blower assembly. ### Claim 6 (depends on 1) The hydronic air heater of claim 1, wherein: said boiler is a low mass condensing boiler. ### Claim 7 (depends on 5) The hydronic air heater of claim 5, further comprising: a control unit in electrical communication with said variable frequency drive, said pump and said boiler and configured to control operation of said boiler, said pump and said blower assembly in dependence upon an input set point temperature. ### Claim 8 (depends on 7) The hydronic air heater of claim 7, wherein: said control unit is configured to determine an optimal air flow for rate through the heating coil to meet said set point temperature in dependence upon a measured fluid temperature difference across the heating coil and a measured air temperature difference across the heating coil. ### Claim 9 (depends on 1) The hydronic air heater of claim 1, wherein: said heater is capable of operation and cold starting at temperatures as low as approximately −40° F. ### Claim 10 (depends on 1) The hydronic air heater of claim 1, further comprising: an air filter positioned behind said inlet air damper and upstream from said blower assembly. ### Claim 11 (depends on 1) The hydronic air heater of claim 1, wherein: said hydronic air heater is an integrated unit that does not require an external supply of fluid. ### Claim 12 A packaged, rooftop hydronic air heater, comprising: a substantially hermetically sealed enclosure having an air inlet; a closed heating loop within said enclosure having at least one boiler for heating a heat transfer fluid, a pump for moving said heat transfer fluid within said loop, and a heat exchanger; an air mover within said enclosure and configured to draw air into said enclosure through said air inlet and through said heat exchanger whereby heat from said heat transfer fluid is transferred to said air to warm said air; and a heat recovery tube configured to recover heat from heat generating components within said enclosure and to exhaust said recovered heat adjacent to said heat exchanger. ### Claim 13 (depends on 12) The hydronic air heater of claim 12, further comprising: a partition within said enclosure, said partition separating an upstream end of said enclosure from a downstream end of said enclosure, said downstream end of said enclosure housing said heat-generating components including said at least one boiler, said air mover and a circulator pump, said upstream end including said air inlet; wherein said heat recovery tube has an inlet within said downstream end and an outlet within said upstream end. ### Claim 14 (depends on 12) The hydronic air heater of claim 12, wherein: said heating fluid is a water/glycol mixture. ### Claim 15 (depends on 12) The hydronic air heater of claim 12, further comprising: a variable frequency drive electrically connected to said air mover and being configured to control a speed of a motor of said air mover. ### Claim 16 (depends on 15) The hydronic air heater of claim 15, further comprising: an integrated control unit in electrical communication with said variable frequency drive, said pump and said at least boiler and configured to control operation of said at least one boiler, said pump and said air mover in dependence upon a heating demand. ### Claim 17 (depends on 16) The hydronic air heater of claim 16, wherein: said control unit is configured to determine an optimal air flow for rate through said heat exchanger to meet said heating demand in dependence upon a measured fluid temperature difference across the heat exchanger and a measured air temperature difference across the heat exchanger. ### Claim 18 (depends on 1) The hydronic air heater of claim 1, wherein: said heater is capable of operation and cold starting at temperatures as low as approximately −40° F. ### Claim 19 A method of heating a structure, said method comprising the steps of: providing an enclosure having an air inlet, a closed heating loop including a boiler, a pump and a heating coil with said enclosure, and a blower assembly with said enclosure; controlling said boiler and said pump to provide a heated fluid to said heating coil; controlling said blower assembly to draw air into said enclosure and past said heating coil to warm said air for distribution to said structure via an air duct; and recovering heat lost from said boiler and said pump and providing said recovered heat to said heating coil. ### Claim 20 (depends on 19) The method according to claim 19, wherein: said enclosure is substantially hermetically sealed. ### Claim 21 (depends on 19) The method according to claim 19, wherein: said step of controlling said blower assembly includes controlling a speed of said blower assembly to provide an optimized air flow rate through said heating coil to meet a heating demand for said structure in dependence upon a measured fluid temperature difference across said heating coil and a measured air temperature difference across said heating coil. ### Claim 22 (depends on 19) The method according to claim 19, wherein: said enclosure is an integrated, packaged unit configured for installation on a rooftop of said structure; and wherein said enclosure only requires an electrical supply and a supply of gas for operation.