How To Clean Squirrel Cage Blower Fan

Air Handler Blower Unit Cleaning
How to Clean the AHU Blower Assembly & Blower Fan

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Steps in cleaning air handler or blower unit for A/C or oestrus pump or furnace systems:

This article illustrates and describes key steps in removing and cleaning the blower fan assembly in an air handler used for air workout or heating.

This article serial describes Air Workout Blower Fan, Cooling Whorl, Fan Coil Unit of measurement Leaks, Mold, and Filter Bug &amp Repairs.

We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick manner to find information you need.

Air Handling Blower Fan Cleaning may ready no air menstruum or weak air menstruum

Hither we describe and illustrate a detailed, thorough cleaning of the blower assembly in an air handler that is used for both heating and air-conditioning.

At page top is a dirty squirrel cage fan within of an air handler unit.

The photo shown only in a higher place/left is a typical gas-fired air furnace or air handler unit. If a cooling coil is installed to a higher place the air handler then the same system may be in use for both ac and heating.

[Click to overstate any image]

Nosotros noted

at DIRTY A/C BLOWERS

that a dirty blower fan reduces the blower assembly air flow rate, increasing heating and cooling costs, and sometimes leading to actual system operating failures such

every bit FROST BUILD-UP on AIR CONDITIONER COILS

that forms non simply frost but solid water ice if the air menstruum rate across even a clean cooling roll is only too slow.

Here in a series of photos we illustrate the basic steps in disassembling and thoroughly cleaning the squirrel cage fan blower associates as well as the compartment into which the blower fan is placed.

In a typical upwards-catamenia air handler render air enters the lesser of the air handler through an air filter.

A squirrel muzzle blower fan located in the unit of measurement lesser rotates to move returning air upwardly through the heat exchanger (that will exist hot if the furnace is in heating fashion) and then further up through an evaporator/cooling roll (that volition be chilled by refrigerant if the system is in air-conditioning or cooling mode).

I have made air period measurements confirming a 50% or more improvement in the air flow of a heating or air conditioning blower unit when dirt is cleaned from the blower fan assembly.

Surprisingly, even a small-scale corporeality of dirt and droppings makes a big reduction in airflow. That'southward because it doesn't take much grit and clay to fill up the slight curvature of the fan blades in these units.

Dead Birds, Rodents in the Flue

Above: fifty-fifty before looking at the blower fan itself the service technician removes the flue vent connector to audit and if necessary clean that component.

In our photo you can see a nicely dried dead bird who fell downwardly the system chimney or perhaps even entered it deliberately - and could not escape.

Inspect the Air Filter

James Agzigian, 3 Zigs Heating and Cooling, a Blood-red Hill New Jersey HVAC service visitor was kind enough to both permit photographs of the air handler blower assembly cleaning procedure and to betoken out some key steps in cleaning and reassembling the unit for safe, effective operation.

For U.S. readers in New Bailiwick of jersey, James' contact data is at the end of this commodity.

Above: the air filter is pulled for inspection and typically, replacement. If at that place is no air filter in the system we know it has not been operated properly and we expect it to exist fifty-fifty more than dust and droppings chock-full than usual.

Spotter out: For effective operation of this system it is essential that it never be operated without air filters in identify.

See AIR FILTERS for HVAC SYSTEMS.

Notice in a higher place that the service tech uses a powerful work calorie-free to begin his inspection of the blower unit. There's little chance of doing a slap-up cleaning chore if you're working in the dark.

Below: earlier beginning mechanical removal of the blower assembly it's of course necessary to plough power and fuel off to the heating/air conditioning air handler unit and then to remove excursion boards and wires that are in the way.

I'd have been compulsively labeling every wire and so that I could plug each back in to its original connection bespeak, but an experienced service technician will appear to exist moving much faster: he already sees which wires power what and he knows where they connect on the circuit control board.

Someone less experienced may spend time afterwards pouring over the wiring diagram (to a higher place) if she forgot to note where the wire connectors belong.

Beneath: having disconnected the wires and removed the circuit board the technician can un-commodities and slide out the blower assembly from its compartment in the bottom of this air handler unit or AHU.

Both in a higher place and in the photograph below y'all can run across the whole blower assembly sliding out of the air handler base. Typically in that location are 2-4 bolts that secure the associates to the bottom of the AHU.

Now let's accept a closer await at the squirrel cage fan itself. In our first photo below the fan doesn't look that muddy - not besides bad. But take a look at the 2d photograph below. At that place yous'll see in cross section how dirt and debris blocks and changes the shape of the curved fan blades.

Below James is pointing out that at some betoken this blower fan was wet: mayhap from condensate spilling downwardly through the air handler from a blocked condensate drain above.

Water spinning off of the blower fan leaves a center trail of corrosion on the air handler blower enclosure.

Earlier farther disassembly of the blower fan from its direct-drive motor (some units utilize a pulley-driven fan motor) nosotros look into the bottom of the air handler return air plenum (beneath).

The dust and debris needs to be cleaned from this infinite besides.

This is an area where I sometimes have plant expressionless mice or other little critters, and once a dead skunk: all are a potential bacterial hazard in the organization.

Below James has flipped the blower assembly on its side so that we can see the accumulation of dust and pilus on the blower motor. Excessive debris on the motor's air inlet openings tin can cause motor overheating and may reduce its life.

Below: the motor for the blower associates fan is mounted with three bolts to the squirrel muzzle fan housing (red arrows).

James takes care to number both the motor brackets and their position on the housing. Why? Well look at all of those holes for other fan mountings. We need to be able to re-get together the blower fan motor in the factory-position after nosotros've disassembled and cleaned these parts.

I sometimes accept a photo of the position of parts and wires too, because on occasion the cleaning process may wash off my re-assembly numbers or marks.

Below you can run across in a closer image the thick greasy pilus and dust on the blower motor.

Below is Aero Krome, a spray penetrating lubricating product that this service tech uses to loosen jammed bolts or drive shafts - a step necessary clean metal and electrical parts.

Stance: What virtually spray foaming the fan instead of taking it apart for cleaning?

Some service technicians try cleaning the blower fan without any disassembly, using a spray foam cleaner - the same production that's used to clean a muddied evaporator coil.

(See Dingy COIL CLEANING PROCEDURES). In the case of the evaporator gyre, because we don't want to cut a refrigerant line nosotros can't remove the ringlet for cleaning. But that'south not the case with the blower assembly in the air handler.

Not merely does blower associates removal permit more thorough cleaning of all of its parts, that approach avoids dripping messy broth into the bottom of the air handler into areas where it is impossible to clean without removing the whole fan assembly.

So the service tech is simply moving crud from one identify in the air handler to another - the AHU bottom - where it will soon be dorsum in the fan associates.

To clean these muddied parts the service tech took them outside to a work area where they could be sprayed make clean and dried.

First the motor and the control board are cleaned, then the round squirrel cage fan itself as well equally the fan housing are cleaned thoroughly, then brought back within for re-associates.

Below are ii photos of the cleaned squirrel cage fan. In our second photograph you can meet a tiny metallic clip in the photo upper left corner.

Sentinel out: don't remove much less lose a clip similar this. This little weight was installed at the mill to balance the rotating fan. An un-balanced fan will quickly wear out its bearings and thus neglect.

Our first photo beneath shows the circular blower fan set into the fan housing.

In the second photo James is pointing to the leading border of the squirrel cage blower fan blades, noting that information technology'due south too easy to re-assemble a blower fan with the blades facing backwards!

Replacing the squirrel muzzle blower fan into its cage it's critical to think to confront the blades in the correct direction. James is pointing to the curved bract showing us that it's scoop faces in the direction of rotation.

Putting the blower cage in backwards looks just fine to an amateur just the air output of the blower assembly will be shut to nada. It'due south a lot of trouble to pull the whole associates apart again to right this mistake.

Watch out: if y'all have problem slipping the blower fan dorsum onto the motor drive shaft, don't strength information technology or y'all may bend something and you lot'll be sad. Rust and corrosion on the shaft can make re-assembly difficult. Try using emory paper to clean the shaft surface until you can sideslip the fan back in place.

Beneath James' gloved mitt is showing how the air deflector volition mount onto the rear of the blower frame and I'g pointing with my thumb to the curved blades are facing towards-it and my index finger points to the direction the curved blades are facing - the management of rotation.

James notes that on occasion he finds a service tech or DIY air handler cleaner person who only leaves the air deflector off when reassembling the unit, possibly considering he couldn't call back how to position it. Once again the result is significantly-reduced blower assembly output.

In our next photo James is replacing the directly drive motor that operates the fan, taking care to mountain the motor in the same position as it was before disassembly. Otherwise y'all might observe that wires don't accomplish their connection points or the fan may not be properly centered in its housing.

Beneath: with the squirrel cage fan in place, the motor properly re-mounted onto the blower frame, and the air deflector properly replaced and secured (right side of the blower frame in our photo), James gives the fan a spin to be sure that it rotates freely and evenly - a low-tech test worth making before the blower associates is replaced in the air handler and the wiring connections restored.

The blower assembly is now returned to the bottom of the air handler and bolted into identify, and so the control board and wire connections are replaced and, of course, the service tech returns the system to performance and waits to come across that it runs properly earlier packing up tools and leaving the task.

Lookout out: If you permit the filters to become very dirty you may need expensive special cleaning or other repairs.

See BLOWER FAN Performance & TESTING.

COOLING MAINTENANCE TIP: The HVAC blower assembly should be serviced every two years. Without proper service the system may have no more than a five year lifetime.

• James Agzigian, three Zigs Heating and Cooling, heating and air conditioning service contractor in Cherry Hill, New Bailiwick of jersey. Tel: 609-425-8313, Email: zig@threezigs.com, Website: http://threezigs.com/ Special thanks to James for tolerating questions and permitting photographs as he cleaned the air handler blower assembly shown in the photos of this article.

Question: Ac Blower Fan Wobbles out of Residue after Cleaning

Air Handler Blower Unit Cleaning

Just saw your website and this topic..Spent the afternoon cleaning my Trane unit of measurement so thought to share a pic or two.

Y'all can see in 1 pic the enormous pile of dirt from the blower.

No troubles with the re assembly simply the fan is wobbly or out of balance only a bit now.

Not noisy now but tin can hear the air"pulsing" some while standing next to the unit..

Even so has the factory motor and fan blades all from a 2005 install.

Feel free to utilise any moving picture delivered. - Anonymous past private email 2020/02/12

Reply: check for lost balancing clips or weights on the blower wheel

Thanks Smilin' I will add together these photos to our discussion on cleaning blower fan assemblies and volition transport along that link.

Almost the HVAC blower fan squirrel cage fan residuum trouble, we want to accost that as else the wobble might ruin the fan assembly, motor, motor begetting &c. especially on direct-bulldoze units.

Have you looked for original blower fan balancing weights or clips that might accept gotten moved or merely lost entirely? Often there are simple spring-type clip-on weights along the circumference of the fan.

Above: HVAC squirrel cage blower fan balancing clips as provided by CD International, cited below. One or more clips of the proper weight are clipped onto the edge of the squirrel cage blower fan associates to correct out-of-balance wobble. Information technology is possible to disturb, move, or lose 1 of these clips during cleaning.

These are sold in fractions of an ounce weight (0.2 oz increments). (Larger blowers and commercial units might take longer curved weights that prune onto the curved blower fan blade rather than onto the edge of the fan rim.) I'll illustrate in attachments.

• have yous double checked that at that place's not a bad bearing that's causing wobble?
• is it possible in that location'due south uneven removal of clay or debris?
• are there aptitude components?
• is this a belt-driven fan or straight drive? If belt, check the pulleys for alignment and tightness and the belt for damage

These HVAC squirrel cage blower fan balancing weights are provided by HVAC suppliers including the source of the photo excerpts of blower fan weights above:

• C D International, Inc., 5550 Shimerville Roadn Clarence, NY 14031 USA, Tel: 716-741-8851 Website: https://www.balancingweights.com/standard-squirrel-muzzle-clips/?sort=priceasc
• Mr. Shims, Tel: (800) 72-SHIMS Website: https://mr-shims.appspot.com/balancingweights.jsp Email: info@mrshims.com
• Reliability Direct, Website: https://www.reliabilitydirectstore.com/ Tel: (281) 957-5283
• Your local HVAC supplier

Reader follow-up: balancing clips in place, suspect failing fan bearing

"...take y'all looked for original blower fan balancing weights that might accept gotten moved or simply lost entirely..."

Ans: I noticed the clips right away..has ane larger and one smaller..made sure they were still in place after scraping / cleaning.

Did observe that when checking for proper balance, no matter what starting point and no thing how many times the fan is spun, information technology ever stops a petty difficult and has a slight movement, maybe 3/8 inch additional rotation.

Probably the output begetting. Feels a lilliputian tiny bit rocky when moving the bract past hand.

Fan may have been out of remainder for some time with dirt deposits and acquired a little spot in the begetting; or, fan motor "sealed begetting" merely normal for age and apply..

Went in and re tightened some canvass metal mount screws...can't really "hear" air pulsing and is running very repose. Seems like a skilful mate between the fan casing output and the duct.

But, when u place a hand on the chiffonier you can feel the fan slightly.

So, will bulldoze it till the wheels fall off, kinda like my quondam Ford Bronco..

Reply: Mark the orignal location so try adjusting the balancing bound-clip weight location on your wobbling blower fan

Well the one-time Ford Bronco had a very long alive and a large following of enthusiasts.

I agree that from your description information technology sounds like a failing bearing.

Withal you lot might want to try this:

• Marker the original location of the existing spring-clips on your blower fan, and then effort moving one of them to one side by nigh 2-inches.
• Run the fan and observe if the residuum is better or worse.
• A bit of experimenting might let you fine-tune the balancing clip location to smooth out the fan operation.

Reader Comments & Q&A

Alan

Dis-assembling a blower unit of measurement squirrel muzzle fan for cleaning is a widely-used service process and cleaning it tin can brand a very significant improvement in air-flow.

The unit is designed to exist able to exist removed, cleaned, lubricated, and reinstalled.

If disassembly shows that in that location was a warn-out bearing or a damaged blower fan then in that example the blower associates needs replacement.

Hi can y'all tell me if cleaning the squirrel cage in an older unit is a risk because disassembly can cause the unit to piece of work incorrectly? And if so should it be left highly muddied or replaced at that indicate?

Bill

I don't know what brand and model air handler you're working-on and then I tin but wave arms and speculate.

Often the blower is incommunicable to work-on while it's inside the air handler;

Some of those models mount the blower on slider-track so that you can loosen a couple of bolts and slide information technology out for access.

On other models y'all unbolt the unit from the chiffonier flooring and merely drag it out.

Senior to senior speaking, that is, don't get ripped on a precipitous sheet metallic corner.

Been searching the web for info on how to access a pre 1980'south HVAC Suirrell and Blower Motor that is enclosed and settig dorsum from the Aor Handler, making information technology hard to get to. Do I remove portioj of interior wall or what?

Certain appreciate your web, and then that I may observe a solution. Present Unit is 20 urs old buit still working, only hearing faint noise recently. Can you lot suggest something to a senior, Thjanks

Wiring error
Fan blocked
Bad start or run capacotor

Fan on sons forest furnace would not start at times it would only buzz .and so he put a new motor on and later on that 24-hour interval he smelled something and went and found the new motor on burn down why?

https://inspectapedia.com/estrus/Furnace_Fan_Cycles_During_Heat.php

May be of apply

Hi, many thanks for all your help with short-cycling furnace, mine comes on, runs 2min, and thermostate clicks, and unit shuts off, leaving house cold, until next endeavour, this is a bryant, 90plus, side vent to outside, propane gas, on subcontract firm in cardinal illinois,

thank you again volition endeavor to check all these out, equally they said maybe flame sencer, I installed new one, aforementioned issue, thank you for your expert communication, Dave

Take a look at the airflow or air output;
Take a look visually at the blower fan itself for the amount of dirt on the squirrell cage fan blades.

As I've noted, you can as much every bit double the air output if the blower is dingy;

I recently establish your site and the data I've looked at has been informative and thorough. I'g not sure if this comment is attached to the article I'm referencing, only in instance it is non I am referring to Air Handler Blower Unit Cleaning with all the photos of the process done by 3 Zigs.

My situation is an original unit of measurement in a house built in Dec 1998. The unit of measurement is a 5-ton, 10 SEER Trane with a gas furnace. The blower assembly was replaced in Aug. 2008. The indoor/outdoor components take had almanac maintenance most years.

I am expecting to replace the arrangement in the next 1-ii years simply am trying to hold off as long as possible. The refrigerant lines started to freeze upwardly in mid-July due to a low R22 level in the system, which I knew from the yr earlier. It was serviced and five.5 pounds of R22 added.

Since then it has not been freezing upwardly and keeping the 3-story house comfortable enough if non perfect on the 3rd floor. I'chiliad wondering if the kind of blower unit cleaning y'all draw would exist worth the toll to extend the life of the arrangement.

I live in West Chester, PA, due west of Philadelphia. If yous think this cleaning would be beneficial, what would be a fair cost to pay for it? Thanks for any guidance.

Give thanks yous for all the wonderful information!

...

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