# US 10,480,875 B2 · Method and system for cleaning heating, ventilation and air conditioning systems

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- Number: US 10,480,875 B2
- Document ID: US10480875B2
- Status: Granted
- Kind: B2
- Application number: 15/280,693
- Filed: 2016-09-29
- Published: 2017-07-06
- Granted: 2019-11-19
- Earliest claimed: 2015-09-29
- Assignees: Blue Box Air, LLC
- Applicants: Blue Box Air, LLC
- Inventors: James Metropoulos
- Web page: https://patentgrep.com/patent/US10480875B2

## CPC

- F28G 9/00: Cleaning by flushing or washing, e.g. with chemical solvents (appliances using jets of fluid for removing debris F28G1/16, F28G3/16)
- A61L 2/16: using chemical substances
- A61L 2/186: Peroxide solutions
- B08B 3/003: {Cleaning involving contact with foam}
- C11D 17/0043: {For use with aerosol devices}
- F28G 1/166: {from external surfaces of heat exchange conduits}
- A61L 2202/15: Biocide distribution means, e.g. nozzles, pumps, manifolds, fans, baffles, sprayers
- A61L 2202/16: Mobile applications, e.g. portable devices, trailers, devices mounted on vehicles
- A61L 2202/17: Combination with washing or cleaning means
- C11D 2111/14: Hard surfaces
- C11D 2111/20: Industrial or commercial equipment, e.g. reactors, tubes or engines
- C11D 2111/42: Application of foam or a temporary coating on the surface to be cleaned
- F24F 2221/225: using a liquid
- F28G: CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS (cleaning pipes or tubes in general B08B9/02; devices or arrangements for removing water, minerals, or sludge from boilers while the boiler is in operation, or which remain in position while the boiler is in operation, or are specifically adapted to boilers without any other utility F22B37/48; removal or treatment of combustion products or combustion residues F23J; removing ice from heat-exchange apparatus F28F17/00)
- A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K)
- B08B: CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02)

## Abstract

A method for cleaning, sanitizing, and disinfecting commercial and residential HVAC system includes applying cleaning foam to coils of the HVAC system, the foam including one or more agents that break down organic and/or inorganic fouling debris into particles, the foam removing and carrying away debris from the coils.

## Claims

### Claim 1

A method for cleaning a heating, ventilation and air conditioning (HVAC) system of a building, comprising:
applying a cleaning foam at low pressure into a plurality of spaces between or within one or more heat-transfer coils of a heat exchange system of the HVAC system, the heat exchange system having a front side for air intake during operation of the HVAC system and a back side through which air exits during the operation of the HVAC system, wherein the cleaning foam is applied to the front side of the heat exchange system, wherein the cleaning foam comprises water, air, surfactant, enzymes, and least one of chlorine dioxide, halide salt, hypochlorite salt, organic solvent, quaternary ammonium compound, acid, base, or chelating agent;
causing or allowing the cleaning foam to pass through the plurality of spaces;
the cleaning foam breaking down and removing dirt or debris from surfaces adjacent to the plurality of spaces, including killing and/or removing at least one of bacteria, viruses, fungi, or biofilm from the surfaces, the enzymes assisting in breaking down biofilm if present; and
the cleaning foam carrying away the removed dirt or debris from the plurality of spaces and exiting the back side of the heat exchange system with the removed debris.

### Claim 2

A method for cleaning and disinfecting a heating, ventilation and air conditioning (HVAC) system of a building, comprising:
applying a cleaning foam comprising water, air, surfactant, and enzymes into a plurality of spaces between or within one or more heat-transfer coils of a heat exchange system of the HVAC system, the heat exchange system having a front side for air intake during operation of the HVAC system and a back side through which air exits during the operation of the HVAC system, the heat exchange system containing biofilm and dirt or debris, wherein the cleaning foam is applied to the front side of the heat exchange system;
operating an air handler of the HVAC system, the air handler causing forced air to enter the front side of the heat exchange system and pass through the plurality of spaces and assist movement of the cleaning foam through the plurality of spaces;
the cleaning foam breaking down and removing the biofilm and the dirt or debris from surfaces adjacent to the plurality of spaces; and
the cleaning foam carrying away the removed biofilm and the dirt or debris from the plurality of spaces and exiting the back side of the heat exchange system with the removed debris.

### Claim 3 (depends on 2)

The method of claim 2, wherein the cleaning foam further comprises at least one of hydrogen peroxide, chlorine dioxide, halide salt, hypochlorite salt, organic solvent, quaternary ammonium compound, acid, base, or chelating agent.

### Claim 4

A method for cleaning a heating, ventilation and air conditioning (HVAC) system of a building, comprising:
applying a cleaning foam containing enzymes that break down biofilm into a plurality of spaces between or within one or more heat-transfer coils of a heat exchange system of the HVAC system, the heat exchange system having a front side for air intake during operation of the HVAC system and a back side through which air exits during the operation of the HVAC system, wherein the cleaning foam is applied to the front side of the heat exchange system; during operation of the HVAC system,
causing or allowing the cleaning foam to pass through the plurality of spaces;
the cleaning foam breaking down and removing dirt or debris from surfaces adjacent to the plurality of spaces, the enzymes assisting in breaking down biofilm if present; and
the cleaning foam carrying away the removed dirt or debris, and biofilm if present, from the plurality of spaces and exiting the back side of the heat exchange system with the removed debris.

### Claim 5 (depends on 4)

The method of claim 4, wherein the cleaning foam breaks down and removes biofilm from the surfaces and dirt associated with the biofilm.

### Claim 6 (depends on 4)

The method of claim 4, wherein the cleaning foam kills and/or removes at least one of bacteria, viruses or fungi from the surfaces.

### Claim 7 (depends on 4)

The method of claim 4, wherein the cleaning foam is injected under sufficiently low pressure so that the heat-transfer coils are not damaged and bendable heat-transfer fins of the coils are not damaged.

### Claim 8 (depends on 4)

The method of claim 4, wherein the cleaning foam is produced on-sight by a foam generating system, the foam generating system including one or more inlets for receiving water, air and a surfactant, a foam-generating mechanism, an outlet for generated cleaning foam, and a hose or conduit for conducting the generated cleaning foam to the one or more heat-transfer coils.

### Claim 9 (depends on 4)

The method of claim 4, further comprising introducing air from at least one of an external air supply, external fan, pressurized air line, or portable blower into the plurality of spaces to assist movement of the cleaning foam and removed debris through at least some of the plurality of spaces.

### Claim 10 (depends on 4)

The method of claim 4, the method comprising:
initially applying a thicker cleaning foam to the plurality of spaces to increase residence time and contact of the cleaning foam to the surfaces; and
thereafter applying a thinner cleaning foam to the plurality of spaces to accelerate movement of the cleaning foam and removed debris through the plurality of spaces.

### Claim 11 (depends on 4)

The method of claim 4, wherein following cleaning of the HVAC system, the HVAC system operates with reduced energy consumption and improved air flow.

### Claim 12 (depends on 4)

The method of claim 4, further comprising:
identifying one or more blockage areas within the one or more coils of the HVAC system; and
applying additional cleaning foam to the one or more blockage areas.

### Claim 13 (depends on 4)

The method of claim 4, wherein the cleaning foam comprises water, air, and surfactant.

### Claim 14 (depends on 13)

The method of claim 13, wherein the cleaning foam is free of volatile organic compounds (VOCs) and/or is pH neutral.

### Claim 15 (depends on 13)

The method of claim 13, wherein the cleaning foam further comprises at least one of hydrogen peroxide, chlorine dioxide, halide salt, hypochlorite salt, organic solvent, quaternary ammonium compound, acid, base, or chelating agent.

### Claim 16 (depends on 4)

The method of claim 4, further comprising operating an air handler of the HVAC system, the air handler causing forced air to pass through the plurality of spaces between or within one or more heat-transfer coils, the forced air assisting movement of the cleaning foam and removed debris through the plurality of spaces.

### Claim 17 (depends on 16)

The method of claim 16, the air handler comprising a blower that applies air pressure to a side of the coils and pushes air through the plurality of spaces.

### Claim 18 (depends on 16)

The method of claim 16, the air handler comprising a blower that reduces air pressure to a side of the coils and pulls air through the plurality of spaces.