How Many Open Windows Does A Swamp Cooler Need?

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You have probably heard that swamp coolers or evaporative coolers need to have windows open to work. To find the optimum efficiency for your swamp cooler, you want to know how many open windows you need. You may wonder if all of the cool air will escape to the outdoors, and you will lose your efficiency. This post will answer all of your questions and give you the details you need.

You should have 1 to 2 square feet of a window or open door space for every 1,000 cubic feet per minute (CFM). For example, you have a 4,000 CFM system and windows with 4 square feet of space to the outside when opened. You need 4-8 square feet of space, which is 1-2 windows open, to run this system. 

Now you understand the math equation determining how many windows you need open for your evaporative cooling system. Having a little bit of airflow outside prevents the room from building up too much air pressure. You probably have more questions about swamp coolers. We will talk about how long to run the pump on the swamp cooler and the total amount of time you can run a swamp cooler. We will also talk about the cost of running a swamp cooler and how you can improve the unit’s performance.

A HVAC repair personnel doing some repair work on the swamp cooler, How Many Open Windows Does A Swamp Cooler Need?

How Many Open Windows Does A Swamp Cooler Need?

The purpose of opening windows is to release any pressure that might build up from the swamp cooler bringing air into the home. The strength of your swamp cooling system is essential for answering this question, as well as the size of your windows. The recommended amount of airflow is 1 to 2 square feet for every 1,000 CFM the swamp cooler uses. Swamp cooling units can vary in their airflow capacity as low as 3,000 CFM and as high as 25,000 CFM.

These calculations are based on the recommended range of air changes per hour (ACPH). This is simply the number of times the air is changed over the course of the hour. This requires open doors or windows to allow old air to exit the home while the swamp cooler draws in more air from the outside. The recommended ACPH is 20-40. This means the air is replaced in the room at a rate of one time per 2-3 minutes.

Having more air circulation in your home increases the overall air quality. This applies to all areas of the home, including those not reached by your swamp cooling system. To learn about ways to improve your air quality and air circulation, check out How To Improve Air Circulation In A Room Without Windows.

Hessaire Portable Evaporative Cooler (Swamp Cooler)

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Is Opening The Windows Letting Cool Air Out?

You don’t want to pay the electric company to cool the outdoors. That doesn’t mean that open windows will cause your system to work less efficiently. Open windows are needed to let the pressure out of the room. It also pushes out air with higher moisture content, which reduces the relative humidity of the room.

When your room has lower relative humidity, the swamp cooling system will operate more efficiently. Evaporative coolers are far more cost-efficient and effective at cooling spaces with low humidity.

How Long Should You Run The Pump On Your Swamp Cooler?

The pump on the swamp cooler runs water to the pad, which will make the air blowing out much cooler. If you feel the air blowing out of your unit is not cool enough, you can turn on the pump for 2-3 minutes. After that, you can place the machine on high cool and make sure the windows are open to allow air to move outside. You may want to repeat the steps after a couple of hours if the air blowing out of the unit does not seem cold enough.

Is It Okay To Run A Swamp Cooler All Day?

Running a swamp cooler all day is not a burden on your electrical bill or the environment. If you have a continuous fill swamp cooler, then you will not need to manually fill the reservoir throughout the day. This is fine to run all day as long as the cooler has access to water throughout the day.

The swamp coolers with manual reservoirs will not be effective once the pad inside the cooler dries out. If you have this kind of evaporative cooler, it is best to run when you can add more water to prevent the pad from drying out.

How Can You Improve Your Swamp Cooler’s Performance?

Swamp coolers run most efficiently with relative humidity under 50 percent. This is why swamp coolers are not as common in the humid eastern coast of the United States as they are in the drier western states.

If you live in a humid area, you may want to open more windows to keep the humidity lower. You can also run a de-humidifier, which will counter the humidifying effect of the swamp cooler. Air conditioning units remove humidity from the air, and you can learn more by reading Does Air Conditioning Add Moisture To The Air?

SEAVON Dehumidifiers For Home (560 Sq Ft.)

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Check your unit to make sure it holds enough water to keep the pad damp but not wet. This will give you the optimum performance you want out of your machine. Change the cooling pad once at the end of the season or the beginning of the next season. If you have difficulty with your swamp cooler, you may want to inspect the water level and the pad. If the cooling pad is fraying or has any open spaces, it is time to replace it.

Dial Manufacturing Spin Roll Cooler Pads 36×24

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Are Swamp Coolers Expensive To Run?

The average electrical cost of a swamp cooler is $0.26 per hour. That equates to about $2 for 8 hours of running a swamp cooler each day. Multiply that number by 30 days to find a total of $60 to run your swamp cooler per month.

Compare that to the cost to run an air conditioning unit that you can expect to cost an average of $0.55 per hour to run. That comes to $4.40 per day if you run the unit for 8 hours. When you multiply that by 30 days, the monthly cost to run an air conditioning unit is $132. These numbers can vary significantly based on the energy the unit consumes and the cost of electricity in the local area.

In Closing

The goal of opening windows is to allow enough space for air to flow out of the home that matches the amount of air the swamp cooler is pulling into the house. The recommended number of air changes per hour is 20 to 40 per hour. To obtain this ACPH, you must have 1 to 2 square feet of space for air to flow out of the home for every 1,000 CFM your swamp cooler uses while in operation.

Small manual coolers with only 3,000 CFM will do fine with just 3-6 square feet of space or one window open. Larger units that might use as much as 25,000 CFM will need 25-50 square feet of space, allowing airflow out of the home. This might require as many as five or more small windows to be open. If you have larger windows, then you might only need three windows open for this larger system.

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