We recommend replacing your filter every 6 months for optimal air quality.

<p><style type="text/css" id="isPasted"></style><span data-sheets-root="1">We recommend replacing your filter every 6 months for optimal air quality.<img src="https://attachments.gorgias.help/Oro0V7LaLOx9d83N/hc/z8QbV2P1yl7ogePy/2026030420-29184784-2f9b-4307-a647-f77249173883-screen%20shot%202026-03-04%20at%203.18.20%20pm.png" style="width: 698px;" class="fr-fic fr-dib"></span></p>

How often should I change my filter?

Replacing the filter in your air purifier is easy!. Need to purchase a new filter? You can do so here: 3-in-1 Medical-Grade HEPA Filter

<p><style type="text/css" id="isPasted"></style>Replacing the filter in your air purifier is easy!</p><ol><li style="font-size: 16px;">Unplug the air purifier.</li><li style="font-size: 16px;">Open the back panel and remove the filter.</li><li style="font-size: 16px;">Dispose of the old, dirty, ineffective filter.</li><li style="font-size: 16px;">Take the new filter out of its packaging and insert it into the back of the purifier. The tag with the Windmill logo should be on top and facing you, with the curve of the filter on the top left.&#xA0;</li><li style="font-size: 16px;">Close the back panel, plug in your purifier, and turn it back on.</li></ol><p>Need to purchase a new filter? You can do so here:&#xA0;<a data-fr-linked="true" href="https://windmillair.com/products/3-in-1-true-hepa-filter" id="isPasted" target="_blank" rel="noopener noreferrer" class="fr-strong">3-in-1 Medical-Grade HEPA Filter<img src="https://attachments.gorgias.help/Oro0V7LaLOx9d83N/hc/z8QbV2P1yl7ogePy/2026030420-b75a7cc2-c8d4-403c-a070-ae2eb86bc600-screen%20shot%202026-03-04%20at%203.19.18%20pm.png" style="width: 591px;" class="fr-fic fr-dib"></a></p>

How do I replace my filter?

If you purifier is not turning on, make sure you try holding the power button for a few seconds!.

<p></p><p>If you purifier is not turning on, make sure you try holding the power button for a few seconds!</p><img src="https://attachments.gorgias.help/Oro0V7LaLOx9d83N/hc/z8QbV2P1yl7ogePy/2026030420-062a81c1-0b91-49ef-a202-ae5f83c4817a-screen%20shot%202026-03-04%20at%203.26.00%20pm.png" style="width: 698px;" class="fr-fic fr-dib"><p></p>

Troubleshooting the purifier

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Windmill

Cleaning & Maintenance

Products

Air Purifiers

What are the specs such as weight, dimensions, dbs, energy guide etc.

What makes the Windmill AC unique?

Will the Windmill AC work in my window? Can I use it through the wall?

What are the product specs for the AC?

Why is choosing the right size AC unit for the room space important?

Can my window AC cool several rooms at once?

FAQs

Where can I find the installation guide and owner's manual for my AC?

How do I install my Windmill AC?

How do I install the carbon filter?

How do I insert the activated carbon filter?

Do you have tips for plexiglass installation?

Do I need a support bracket?

How do I install the AC in a storm window?

How do I install the cosmetic side panels?

How do I uninstall my AC?

Installation

What is the red circle on the display?

How do I clean and maintain my AC?

How do I clean and replace the filters?

Is there a drain hole?

Why is my AC not cooling?

Why does my unit sound noisy?

What do I do if my AC is leaking?

Why is there ice on my AC?

Why is my app showing offline?

What happens if my AC is too powerful for my room?

Troubleshooting Support for Window AC

What makes the Windmill fan unique?

How can I get the most out of my fan year round?

What are the technical specs to the Fan?

What square footage is the Windmill fan best for?

Can it be mounted on the wall?

Can I adjust the height of the fan?

Can I use my Windmill fan outdoors?

Does the Windmill fan oscillate?

Where is the Fan Manual?

What outlet does the Windmill Fan require?

How many fan speeds are there?

How do I operate the fan?

How do I clean the fan?

Fans

What makes Windmill purifiers different from other purifiers?

What are the technical specs to the purifiers?

Why do I need a purifier?

How do the Windmill purifiers work?

What do the Windmill purifiers actually purify?

How fast can the windmill purifiers clean my air?

Where should I place my purifier?

What special smart features do the Windmill purifiers have?

What size room are the Windmill purifiers best for? Which purifier should I choose?

Can I leave my air purifier on all the time?

Do the Windmill purifiers require a wifi connection to operate?

Are the Windmill purifiers loud?

What does laser precision refer to?

What is CADR?

What is AQI?

Where can I find the purifier manuals?

Why am I getting bad air quality notifications when my app is showing that it's good?

How do I use the controls on the purifier? / What are the special functions of the purifier?

Purifier FAQs

What filters do I need to use with the Windmill purifiers?

What is a 3-in-1 HEPA filter?

How many filters are in the Windmill purifier?

How does the filter reduce odors and smoke?

What happens if I don't replace filters in an air purifier?

How do the replacement filter refills work?

What is HEPA?

Filter FAQs

Do I need to be concerned about airflow?

Should I layer my 1" filters?

What is the difference between the Windmill filters?

Will Windmill Filters help my allergies?

Are Windmill Filters good for pet owners?

Which Windmill filter is best for me?

What particles do Windmill filters capture?

What sizes do you offer?

Why does Windmill ship in bulk?

Can I buy just 1 filter?

How does the quiz work?

Are Windmill Filters recyclable?

How do I store my filters?

Can I wash and reuse my filters?

How do I dispose of my filters?

How do I change/install my air filter?

What are the product details?

What makes Windmill filters unique?

Where are Windmill Filters made?

How do I sign up for text reminders?

How do text reminders work?

How do I know my air filter is working?

Can you place a 1" filter in my larger 2", 3", or 4" wide slot?

How does Windmill reduce its carbon footprint?

What is an air filter?

Do I need an air filter?

How does an air filter work?

What are the benefits of an air filter?

Why do I need to change my air filter?

When should I change my air filter?

Where is the air filter in my home?

Can I use a HEPA filter in my furnace?

What is MERV? What about MFR and FPR?

How does where you live affect what air filter I should use?

Why are there different size air filters?

How do I know my air filter size?

What is the difference between fiberglass and pleated air filters?

What is the difference between an Air Filter and an Air Purifier?

HVAC Filters 101

Where can I manage my account and auto-refills?

How do I contact customer support?

How do your annual auto-refills work?

When will my HVAC filters arrive?

Orders - HVAC

HVAC Filters

What is Mulberry?

What is included in the Mulberry Protection Plan?

Do I qualify for Mulberry Protection Plan options?

How do I purchase a protection plan?

Mulberry Product Protection Plan

How can I use HSA/FSA funds for A Windmill purifier?

Do I need to pay taxes on my order?

Can I cancel or change an order after it's been placed?

How can I track my order?

I placed my order but didn't receive my confirmation email. What do I do?

Orders

When exactly will my order arrive and how much is shipping?

Where does Windmill ship?

Do I need shipping insurance protection? How do I file a claim with Onward?

Shipping

Orders & Shipping

How do I register my Windmill product for the included warranty?

Does the Windmill AC come with a warranty?

What is the warranty for the Windmill Fan?

What is the warranty for the Windmill Air Purifier?

Warranty

What is your return policy?

Returns

Warranty & Returns

Where is your end user agreement for the app?

What are the mobile app features for my AC?

Can I control the Windmill AC remotely?

How can I connect the Windmill AC to the mobile app?

How can I connect my AC to my Alexa?

How can I connect my AC to my Google Home?

How can I use Alexa to control my Windmill AC?

How can I use my Google Home to control my Windmill AC?

How can I reset my app?

How do I connect my fan to the app?

Do I need 2.4 or 5g network to connect?

What should I do if my app goes offline?

What should I do if my app is stuck on the same temperature?

What should I do if my app is reading 0 degrees?

General & Troubleshooting

How do I set a timer?

How do I set an automation?

Automations & Timer

Mobile App

How do I manage my filter subscription?

How often will I be billed for my filter subscription?

What are activated carbon filter auto-refills?

Subscriptions

Is the Windmill AC more eco-friendly?

How can I use my AC more efficiently and save on my energy bill?

How does the carbon offset program work?

What is R32?

What is Windmill's Eco Rewards Program?

What if I need to reset my utility login to sign up for Eco Rewards?

Eco Rewards

What makes the Windmill fan more eco friendly?

How does the fan help lower my energy use?

What does it mean that your fan has internal parts made with 50% recycled materials?

Sustainability