When it comes to finding a solution to your heating problems, window air conditioners are a definite bet. Shopping for window A/C units may be daunting and leave you with many questions because there are many different varieties and distinct designs to suit our lifestyles. 

Window air conditioners nowadays are a lot better than they used to be, and they aren’t nearly as energy-guzzling as they previously were. Modern window units give respite from the oppressive heat, reduce humidity, and consume less energy than ever before. 

Don’t worry—we’ve gathered and answered the most commonly asked questions regarding window air conditioners to make your purchasing and using experience go as smoothly as possible. According to our analysts, these are your most frequently asked questions concerning window air conditioners. 

You can also get the aid you want by looking up all of the usual causes and signs for window air conditioner’s problem answers, all in one spot.

Window Air Condiotioner Common Problems Answer

Window Air Conditioner Common Problems Answer

You may have many questions in mind when thinking about your window air conditioner, or you might need answers to some common problems. Here is a list, and I will go through all about Window Air Conditioner Common Problems and other FAQs in this one article.

The questions covered are: 

  1. What size window air conditioner do I need?
  2. Where should I install my window air conditioner?
  3. What are the benefits of a window air conditioner?
  4. Is it hard to install a window air conditioner?
  5. Can I install the window air conditioner myself?
  6. How do I clean and maintain the air conditioner?
  7. How do you clean a window air conditioner without removing it?
  8. Can I leave a window air conditioner unit installed during the winter?
  9. Why won’t the air conditioner turn on?
  10. Thermostat Glitches Of Window Air Conditioner 
  11. Is it normal for water to drip from the window air conditioner?
  12. Why is ice building up on the coils behind the air filter?
  13. Why is water leaking into the room from the air conditioner?
  14. Why does my window air conditioner short cycle?
  15. How do I know if my window air conditioner is low on Freon?
  16. How do I add refrigerant to my window air conditioner?
  17. Low Efficiency Equals Low Refrigerant
  18. Will window air conditioners work in any window?
  19. What is a “SEER” rating?
  20. What is a BTU?
  21. How much energy does a window air conditioner use?
  22. Will Energy Star rated models to save money?
  23. How often should I clean the air filter?
  24. What is a common problem with window air conditioning units?
  25. Do window air conditioners need water?
  26. Does window AC take air from outside?
  27. Do window air conditioners cause negative pressure?
  28. Why is my window AC not getting cold?
  29. How long should window AC run?
  30. How do window air conditioners drain?
  31. Do window AC units run constantly?
  32. What is the best setting for a window air conditioner?
  33. What is fan mode on a window air conditioner?
  34. Does window AC circulate fresh air?
  35. Can a window AC unit be used inside?
  36. How much window AC do I need outside?
  37. Can you set a window air conditioner on a table?
  38. Can you leave the window AC on all night?
  39. Where is the drainpipe in a window air conditioner?
  40. Why is my window AC sweating?
  41. Can you leave a window air conditioner in the rain?
  42. What can I do to enhance the efficiency of my window air conditioner?
  43. Why is my air conditioner running but not cooling the house?
  44. Why does my window unit keep freezing up?
  45. How can you tell whether your air conditioner is working correctly?
  46. What happens if the window AC is not tilted?
  47. Can you put a window AC sideways?
  48. Can window AC cool the entire house?
  49. Do window AC units turn off automatically?
  50. How far does a window AC stick out?
  51. Can you add Freon to a window air conditioner by yourself?
  52. Is it normal to hear water in your window air conditioner?
  53. Should I drill a hole in my window air conditioner?
  54. Should a window air conditioner unit be level?
  55. How long should a window air conditioner sit before turning it on?
  56. Can window air conditioners catch on fire?
  57. How much does it cost to refill a window air conditioner with Freon?
  58. Can I spray Lysol in my window air conditioner?
  59. Are window air conditioners toxic?
  60. Is it cheaper to run central air or window units?
  61. Are window AC units loud?

With all that said, let us dive into details so you can find what you’ve been looking for…

1. What Size Window Air Conditioner Do I Need?

Window air conditioners with 7,000-8,000 BTUs are ideal for rooms up to 250 square feet. Spaces ranging from 300 to 425 square feet, on the other hand, would benefit from a unit with a cooling capacity of 10,000 to 12,000 BTUs. 

Larger rooms, ranging from 425 to 525 square feet, require a window air conditioner with a cooling capacity of 14,000 BTUs.

2. Where Should I Install My Window Air Conditioner?

There are various aspects to consider when deciding on the best position for your window air conditioner. To guarantee that you purchase the proper window air conditioner for your needs, view the ceiling height, the number of doors and windows, quantity of sunshine, user traffic, and the room’s function.

Adjustments for these variables must be made, according to Energy Star, to get the most out of your appliance. The BTU capacity should be lowered by 10% if the space does not receive as much sunshine or is substantially shaded. However, if the room is exceptionally bright, the BTU capacity should be raised by 10%. 

For the quantity of traffic, if more than two people usually occupy the room, the capacity should be increased by 600 BTU per person. Kitchens should have 4,000 BTUs added for room functioning.

3. What Are The Benefits Of A Window Air Conditioner?

Many features make window air conditioners a popular choice for many homes, apartments, and offices:

Air conditioners for windows are inexpensive! They range in price from $200 to 900 dollars. They are not only less expensive to buy, but they are also energy efficient and will not raise your electricity costs.

Installation does not necessitate the use of a skilled HVAC contractor. It may be completed in a short amount of time by two individuals. Window air conditioners don’t necessitate any significant alterations to your home’s structure.

You can take the window air conditioner with you if you change houses, flats, or businesses because the installation process is so straightforward. It’s also possible to relocate it to another room in the house.

A window air conditioner is an attractive choice if the air conditioner isn’t chilly enough in a hotspot. Adding a window unit, especially in bedrooms during the summer, can be a practical and straightforward option.

4. Is It Hard To Install A Window Air Conditioner?

In most cases, window air conditioners may be installed in as little as 15-20 minutes. An installation kit and instructions are included with all window air conditioners. Follow the manufacturer’s installation instructions before plugging it in.

5. Can I Install The Window Air Conditioner Myself?

Yes, window air conditioners offer an easy-to-install design that helps you save money while also ensuring speedy cooling. The installation process may be done in a short amount of time once you’ve picked the ideal position for your window unit and checked that it has the necessary dimensions.

It’s critical to eliminate anything that can get in the way of the installation procedure so that you can get to the window quickly.

6. How Do I Clean And Maintain The Air Conditioner?

When it comes to being comfortable in your house, cleaning the air filter is critical. Reusable filters are used in certain window air conditioners, whereas replacement filters are used in others. 

See your owner’s handbook to determine which cleaning/replacement method is best for your device. Start by carefully cleaning reusable filters with warm water and small dish soap or white vinegar. 

Allow the filter to dry before reinstalling it in the air conditioner fully. If the device has a removable filter, it should be updated every two months at the very least.

7. How Do You Clean A Window Air Conditioner Without Removing It?

Use the vacuum with the soft brush attachment to clean the window air conditioner without removing it. Carefully suck out any dust balls or other debris you find in the unit. After that, combine your water with two drops of dish detergent. After that, spray this inside the machine and wipe down the affected parts.

8. Can I Leave A Window Air Conditioner Unit Installed During The Winter?

It’s crucial to study the owner’s handbook that came with your window A/C unit when determining if it can handle the winter cold. To guarantee that the team can withstand the climate, we recommend following the manufacturer’s guidelines.

It’s necessary to take specific steps to adequately store the air cooling unit—whether it’s securing it with a tarp or a strong plastic cover—avoiding moisture getting into the team. If the window air conditioner includes heating capabilities, it’s critical to safeguard the device while ensuring that the airflow is not obstructed.

9. Why Won’t The Air Conditioner Turn On?

When you start your air conditioner troubleshooting evaluation, one of your biggest concerns could be that you’ll turn on the system and hear and feel nothing. A fuse that is blown or a tripped circuit breaker might be the source of the power outage, requiring you to reset the circuit breaker or replace the fuse. 

It might also be the consequence of faulty wiring or a malfunctioning thermostat. Check the power cable for an overcurrent detecting device, which usually is present. 

Whether the over-current detection device has been tripped, try resetting it and seeing if the air conditioner turns on. Check to see if the electrical outlet is operational. Check for a tripped circuit breaker in the home.

10. Thermostat Glitches Of Window Air Conditioner 

It’s possible that if your thermostat is broken or poorly adjusted, it won’t instruct the air conditioner to turn on. If your thermostat is set to the lowest temperature and the system still won’t turn on, it’s time to call your HVAC repair specialist, who will most likely need to recalibrate or replace the thermostat. 

Calibration issues are more familiar with older dial-type thermostats, although contemporary programmable thermostats can sometimes be challenging to program. Check your thermostat handbook to ensure you’ve configured it correctly when troubleshooting your air conditioning system.

11. Is It Normal For Water To Drip From The Window Air Conditioner?

Yes, many window air conditioners are built with water dripping from the unit’s outer base.

The humidity removed from the room by the window air conditioner gathers on the evaporator fins and drops down to the cabinet’s base pan. The water then drains to the house’s exterior through the base of the air conditioner cabinet.

12. Why Is Ice Building Up On The Coils Behind The Air Filter?

Ice may form on the coils of a window air conditioner due to various circumstances. Dust, dirt, or debris can clog the fins and coils, limiting airflow and forcing the compressor to work so hard to compensate for the lost cooling power from the blocked waves that it reduces the coil temperature below the usual range. A clogged air filter has the same effect.

Another possible reason is decreasing the intended temperature too low, which causes extra condensate to accumulate on the coils, lowering the temperature and causing ice.

Ice formation on the evaporator coils behind the air filter can also be caused by running the fan at a low speed for an extended length of time.

13. Why Is Water Leaking Into The Room From The Air Conditioner?

Water can seep into a room if a window air conditioner is fitted incorrectly. The unit’s outer edge should be somewhat lower than the interior edge so that the water drains outside rather than within.

A blockage in the drain pan, which gathers condensate during operation, might cause water to flow into the room.

Another possibility is that warm damp air from outside the window is leaking into the air conditioner casing, where the moisture condenses and drips into the room. To solve the problem, use expansion foam to seal air spaces.

14. Why Does My Window Air Conditioner Short Cycle?

The compressor turns on and off at brief intervals due to various factors. The thermostat or temperature sensor may be broken or blocked. Refrigerant leaks and ice coils can also cause short cycling. Another source of this issue is the installation of an air conditioner that is too large for the room to be cooled.

15. How Do I Know If My Window Air Conditioner Is Low On Freon?

Five Signs Your Air Conditioner Is Running Low on Freon.

  1. Cooling down your house takes a lot longer than it should.
  1. Your utility costs are significantly greater than usual.
  1. The air that comes out of your vents isn’t icy.
  1. On your refrigerant line, ice has started to form.
  1. You’re hearing strange or loud noises coming from your ac unit.

16. How Do I Add Refrigerant To My Window Air Conditioner?

It is not a do-it-yourself repair to add refrigerant to your window air conditioner. The Environmental Protection Agency regulates the recovery and recharging of air conditioner refrigerant (EPA). 

Unless a refrigerant line is leaking, you shouldn’t need to add refrigerant. A sealed refrigerant system in your air conditioner should only be recovered, repaired, and recharged by an EPA-licensed technician.

How Do I Know What AMP My Air Conditioner Is

17. Low Efficiency Equals Low Refrigerant

When air conditioning troubleshooting reveals a machine that isn’t working correctly, it might be due to a lack of refrigerant. If the refrigerant level is low, it was likely undercharged during installation or a leak. 

A low refrigerant level might be the cause of your building’s inability to cool adequately or the air becoming sticky. Heat and humidity cannot be effectively removed from the air without the proper refrigerant level. 

Like the engine oil in your car, the refrigerant is the lifeblood of your air conditioning system. Although your AC expert may find a leak throughout the air conditioning troubleshooting procedure, it isn’t always as simple as just topping up the refrigerant. 

When a car requires oil regularly, it is typically an indication of a more significant issue. Low refrigerant in an air conditioner system is frequently a symptom of a leak, and you’ll need trained HVAC professionals to fix it. It’s conceivable that you’ll need to replace the device if many leaks are discovered.

18. Will Window Air Conditioners Work In Any Window?

Window air conditioners are designed to accommodate various window types, including vertically and horizontally opening windows. Many window air conditioners come with expandable panels to fit and seal most window openings. Make careful you measure your window and compare it to the measurements of the air conditioner.

19. What Is A “SEER” Rating?

The SEER rating measures the efficiency of a window air conditioner. The greater the SEER rating, the more BTUs of cooling power your window air conditioner produces per watt of electricity used. The quantity of BTUs divided by the watts consumed per hour yields the SEER rating.

20.What Is A BTU?

The British Thermal Unit (BTU) must cool or heat one pound of water by one degree. The output of window air conditioners is measured in BTUs. Choose an air conditioner with a high enough BTU rating to effectively cool the room where it will be placed.

21. How Much Energy Does A Window Air Conditioner Use?

Divide the BTUs by the SEER rating to determine how much energy your window air conditioner uses. This will provide you with the watts per hour. You can convert it to kilowatt-hours (kWh) by multiplying it by 1,000, which is presumably how your electric company calculates your payment. 

You may then calculate your per hour by multiplying the kWh by your power company’s rate. A 12,000 BTU air conditioner with a SEER of 10 and a fee of 25 cents per kWh, for example, would be calculated as follows:

12,000 BTUs / SEER 10 = 1,200 W = 1.2 kWh

The cost of running your window air conditioner is 1.2 kWh x $0.25 = $0.30 per hour. Your window air conditioner will cost $300 a year to run if you use it for 8 hours a day for 125 days during the summer.

22. Will Energy Star Rated Models To Save Money?

Yes! Energy Star models can help you save up to 30% on your electricity bills. Energy Star certified devices would function more efficiently and waste less energy during the unit’s lifespan due to rigorous energy efficiency criteria.

23. How Often Should I Clean The Air Filter?

Window air conditioners typically require new filters every three months. If you live in a dusty or pollen-filled environment, you may wish to change it more often. Filters that are clogged can reduce the efficiency of your window air conditioner and raise your energy expenditures.

24. What Is A Common Problem With Window Air Conditioning Units?

A filthy air filter and a broken condenser coil are the most typical causes of your air conditioner not producing chilly air. Clean the air filter to see if it helps. Suppose it doesn’t work. Clean and check the unit’s condenser coil on the outside. It may need to be replaced if it is damaged.

25. Do Window Air Conditioners Need Water?

As part of the cooling process, air conditioners create water. Some water is used to chill the air, while the remainder is discharged through the unit’s rear. 

26. Does Window AC Take Air From Outside?

Window air conditioners do not use outside air to cool. Instead, they extract air from within the house and circulate it throughout it. You’re undoubtedly curious why a portion of the unit is left outdoors because there is where it’s supposed to be!

27. Do Window Air Conditioners Cause Negative Pressure?

Portable air conditioners, like window units, use a tiny portion of the air they suck in to expel waste heat. Negative pressure is created when air is sucked out of the room and not replenished. 

As a result, heated air from adjacent rooms will be drawn into the space you’re trying to chill. Warm outside air will be drawn through gaps, window seals, and door frames, replacing the air in the surrounding rooms. As a result, your portable air conditioner will have to work continually to deal with the entering warm air, thereby heating the remainder of your home.

28. Why Is My Window AC Not Getting Cold?

A lack of proper air movement is the most prevalent reason for window air conditioners not blowing cold air. If the air filter is dirty or clogged, there may be little or no air movement over the evaporator coils, causing them to get excessively cold and forming frost or ice, which will further impede airflow.

29. How Long Should Window AC Run?

When using an air conditioner, set it to run for 15-20 minutes at a time. In ideal conditions, an air conditioner should operate for 15-20 minutes at a time in mild temperatures. If it’s less, your air conditioner could be too big for your home.

30. How Do Window Air Conditioners Drain?

Condensation is produced by most modern window air conditioners, which drop into the unit’s bottom pan. There are no drain holes or plugs to remove the water, as with previous style window AC units. If the water level rises too high, it will seep out the AC unit’s backside.

31. Do Window AC Units Run Constantly?

According to experts, running your window air conditioner 24 hours a day, seven days a week is safe. If you run the air conditioner all day, no portion of it will become too hot and melt. If you fail to switch off the air conditioner, neither its performance nor efficiency will decrease.

32. What Is The Best Setting For A Window Air Conditioner?

78 degrees Fahrenheit.

Set your air conditioner to a high setting to begin.

And the ideal temperature is 78 degrees Fahrenheit. It’s an excellent temperature, according to Energy Star. During the day, 78 degrees keeps you cool and comfortable. It shouldn’t also cause your power bill to increase.

33. What Is Fan Mode On A Window Air Conditioner?

Turn on the fan. When the fan mode is turned on, the AC’s internal fan circulates air around the room. This is done without any cooling, similar to how a typical fan works. The main benefit of employing the fan mode in an air conditioner is the evident energy savings provided by the lack of a compressor.

34. Does Window AC Circulate Fresh Air?

Is it willing to bring in the fresh air? No, air conditioners don’t bring fresh air in from outside. Your air conditioner employs a fan to suck air into the machine and spread it across a structure. As a consequence, recycled air is produced.

35. Can A Window AC Unit Be Used Inside?

A window air conditioner may be used in the house, but it will require some changes. As if it were a window, this would enable the heated air to escape to the outside. Another option is to heat one room of the house while cooling another.

36. How Much Window AC Do I Need Outside?

Also, keep in mind that the air conditioner requires adequate clearance for unrestricted air movement, so pick a window free of furniture, trees, bushes, walls, or other impediments on the inside or outside of the window within 20 inches of the unit.

37. Can You Set A Window Air Conditioner On A Table?

Window air conditioners must be vented outside and installed in a window. If a window air conditioner is operating on a table inside, it cannot exhaust heat to the outside and is therefore unable to decrease your inside temperature.

38. Can You Leave The Window AC On All Night?

In summary, scientists and professionals appear to agree that leaving the air conditioner overnight is relatively safe. Use a timer: set your ideal temperature before going to bed and preset the air conditioner to turn off throughout the night, when your body will have cooled down sufficiently for you to sleep soundly.

39. Where Is The Drainpipe In A Window Air Conditioner?

The hole is generally beneath the external area of the unit and may be pretty tiny on regularly draining units (usually older or massive units). Instead of a hole on the side, window air conditioners built to hold water may have a spot on the side that allows the water to drain when it reaches a certain level.

40. Why Is My Window AC Sweating?

Sweating is likely when the air temperature falls below the dew point temperature. Explained, if the dew point of the room is lower than the surface of your air conditioner grille, moisture will collect.

41. Can You Leave A Window Air Conditioner In The Rain?

When it rains, can a window-mounted air conditioner be used? Yes, it is possible to do so. All HVAC heating and cooling devices are built to function in inclement weather. This implies that they will work great even if it rains, as long as the unit is in good working order.

42. What Can I Do To Enhance The Efficiency Of My Window Air Conditioner?

There are seven ways to get your window air conditioner to function at its peak.

  1. Clean the windows
  2. Leave the unit turned off when not in use
  3. Clean the outer part to remove any dirt
  4. Fill the gaps around the window to ensure a better seal
  5. Clean the air filters regularly
  6. Clean the coils
  7. Help It to keep cool by setting an optimum temp and taking care of it.

43. Why Is My Air Conditioner Running But Not Cooling The House?

Blocked Condenser Unit

A blocked or clogged condenser coil might be the cause of your air conditioner working but not decreasing temperatures inside. The condenser fan sucks air into the outside unit through the condenser coil to extract heat energy from your house while it’s working correctly.

44. Why Does My Window Unit Keep Freezing Up?

The Fan and the Fan Motor

A lack of enough air movement is the most prevalent reason for window air conditioners freezing up. Suppose the circulating fan is not functioning or is running too slowly. In that case, there will be little or no air movement over the evaporator coils, causing them to grow excessively cold and form frost or ice, further reducing airflow.

45. How Can You Tell Whether Your Air Conditioner Is Working Correctly?

How can you determine whether your air conditioner is working correctly? If you can hear the fan humming and see the blades rotating, your blower is still functional. Inside, it’s a lot colder. 

Nothing is more unpleasant than returning home after a day in the sun to a hotter environment. The air conditioning machine is acceptable if the inside temperature is colder than the external temperature. Is it true that ner is cooling?

46. What Happens If The Window AC Is Not Tilted?

Water drips from window air conditioners. If it isn’t tilted far enough, though, the water can leak into the air conditioner and perhaps down the interior wall of your home. You’ll need to re-adjust your air conditioner if this happens. If water drips inside over an extended period, fungus and other water damage might result.

47. Can You Put A Window AC Sideways?

The only time you can install a window air conditioner vertically (that is, when the window glides open from side to side rather than up and down) is if the air conditioner is vertically designed. You can harm a standard air conditioner by turning it on its side to fit a window opening.

48. Can Window AC Cool The Entire House?

Window air conditioners are only meant to chill one room at a time. It is quite difficult for such an air conditioner to chill a whole house. With a single window AC, you can cool two adjacent tiny rooms at most, but the cooling will be uneven.

49. Do Window AC Units Turn Off Automatically?

Automatic air conditioners are available. The air conditioner begins to blow cool air when the cooling level is adjusted to a specified temperature. The AC will turn off when the room temperature reaches the preset degree. It will switch on again as soon as the temperature decreases.

50. How Far Does A Window AC Stick Out?

So you’re out of luck unless you have at least a couple of feet between the window frame and the bars. Consider a “in room” air conditioner that sits on the floor and can be wheeled from one room to the next as needed.

51. Can You Add Freon To A Window Air Conditioner By Yourself?

Keep in mind that while you may install Freon to a window air conditioner yourself, the EPA demands that anybody you pay to perform it for you has adequate HVAC certification. If you’re not sure which HVAC professionals are certified, you may use our HVAC technician form to find out.

52. Is It Normal To Hear Water In Your Window Air Conditioner?

Inside the unit, there are water sounds.

You may hear water sloshing about in your window air conditioner unit from time to time. Although the sound is scary, it is pretty natural. Your window unit cools the space by sucking in warm, damp air and cooling it before blowing it back into the room through the indoor coil.

53. Should I Drill A Hole In My Window Air Conditioner?

Draining a hole in the unit is not a good idea. If there is an excessive quantity of condensation, the water can be drained through a 3/4in hole towards the back of the machine. The fan is meant to sling water over the coils to keep them cold, which explains the splashing.

54. Should An AC Window Unit Be Level?

Many people assume that pitching air conditioners down, slightly out of level, can assist them in draining condensate. An air conditioner should be put on a flat surface. Condensate gathers beneath the fan and flows into the slinger ring in these appliances.

55. How Long Should A Window Air Conditioner Sit Before Turning It On?

After moving a portable air conditioner (or any other refrigeration device), it should be left to rest for 30 minutes. Before the appliance is turned on, the fluids will settle into their correct positions. Starting the machine too soon can cause it to break.

56. Can Window Air Conditioners Catch On Fire?

The most severe danger linked with window air conditioners is fire. Room air conditioners have been shown to pose a greater fire danger than central air conditioners. A window unit is estimated to be 1.8 times more likely than a regular unit to start a fire.

57. How Much Does It Cost To Refill A Window Air Conditioner With Freon?

A Freon refill on an air conditioner costs around $150 on average. Depending on the size and kind of your HVAC unit, you should expect to pay between $100 and $350 for a refill. Older big r22 units can cost up to $600. R410a in a 25-pound jar costs $75 to $175.

58. Can I Spray Lysol In My Window Air Conditioner?

Knowing how to clean a window air conditioner may save you money just as much as knowing how to clean your central air system. Scrub the coils on the rear of the unit with Lysol® All-Purpose Cleaner and a stiff brush.

59. Are Window Air Conditioners Toxic?

No, they are completely risk-free. The only thing we would suggest is that you clean the air filter at least once a month while using one of these machines. Otherwise, everything should be perfectly fine is taken care of properly.

60. Is It Cheaper To Run Central Air Or Window Units?

A typical high-quality central air conditioner costs roughly $1,500 but may cost up to $10,000. A window unit costs $300 to $1500, with monthly operating expenses ranging from $30 to $80, depending on consumption.

61. Are Window AC Units Loud?

Although all window units make some noise, the average team produces roughly 50 dB. This is often in the same range as other familiar household sounds. A vacuum cleaner, for example, works at approximately 70 decibels, but a baby’s loud sobbing can reach 110 dB.


Window air conditioners are an excellent method to keep your room cool on the cheap. Taking good care of it will help the unit last a very long time. 

We hope this article has clarified all your desired FAQs and you’ve found Window Air Conditioner Common Problems Answer. Try following all the tips given above and keep an eye on all the problems mentioned to get the best out of your window air conditioner.

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