There are very many types of fans, one perfect for every corner of your home. You can turn off your air conditioning and save money often if you buy enough fans and use them everywhere. This web page describes ceiling fans, whole house fans, and large and small portable fans.


Window Fans
Energy Tips for Using Window Fans
Portable Fans
Energy Tips for Using Portable Fans
Portable Fan Electrical Safety
Whole House Fans
Ceiling Fans
Energy Tips for Buying, Mounting and Using Ceiling Fans
Energy Tips for Cooling Your Home With All Types of Fans

If your top floor doesn’t get cool enough when your air conditioning is running or if you want to use less air conditioning to save money, you can cool your home with fans and make your top floor or your whole house much more comfortable. Learn how to use fans in place of air conditioning in every room of your house.

Fans can create a strong breeze anywhere in your home, and when the outdoor air is cooler than the indoor air, they can draw in outdoor air to cool your home. You will need to do a little work every day moving fans around and opening and closing windows, and you will need to live with a little less comfort at times. This web page is a short course on portable fans, whole house fans and ceiling fans, with many energy-saving tips on each type.

Breezes cool you because air moving rapidly past you causes heat to leave your body, and when using fans you can raise the thermostat temperature a few degrees when air conditioning is running, and you can at times turn off the air conditioning. This allows you to do less repair and replacement of your whole house and window air conditioners. For every degree you turn down your home’s temperature you could lower your air conditioning costs by about 3 percent. So, if you use fans instead of air conditioning you will save money in several ways.

If the upstairs is too hot in summer it may be due to inadequate attic insulation, causing the attic to be much too hot. See the Topic of Home Energy Conservation, Attics. For energy tips on using air conditioners, see the Topic of Home Energy Conservation, Air Conditioning.

If the upstairs does not get cool enough when your whole house air conditioning is running and the basement is being cooled, close the basement registers and check if the basement is cool enough for you. On most AC systems, the top floor receives much more cooled air when the basement registers are closed.


Window Fans

Window fans can be used to cool your home  by bringing in cool outside air or by blowing out warm inside air when the outside air is cool. They have rain-resistant motors and “expander panels”, which slide outward to block air from flowing around the fan. Without them, some of the air blown into the house would flow back out around the sides of the fan whenever the air pressure inside the house is greater than the air pressure outside of the house. Box fans are often used in window openings, but should not be used because they have no expander panels and are not rain-resistant.

There are single blade window fans, which normally have 16″ or 20” blades and are used in double hung windows. There are dual blade window fans, which have two 7″, 8” or 9” blades and are also used in double hung windows, and there are window fans designed for sliding windows and casement windows, called “vertical window fans”. Most of these have three small blades.

types of fans

8″ Dual Blade Window Fan


use fans in place of air conditioning

Single Blade Window Fan with 16″ Blades

cool your home with fans

Vertical Window Fan in Sliding Window

















Single blade window fans create much greater airflow than dual blade window fans, but they block the view through the window. Most single blade fans create airflows of between 2500 CFM and 3500 CFM. Dual blade fans have airflow rates in the range of 750 CFM to 1500 CFM. These ranges are only approximate because most manufactures don’t give them, but they may be printed on the box or on the company’s website or the store’s website. The maximum airflows are similar for fans of a particular blade size with three speeds. They are similar because the fans would be too noisy at a higher speed. The wattages are not given for most window fans, but you can estimate it using the models which do the wattage. One 1400 CFM dual blade window fan uses 70 watts at high speed and one 3560 CFM single blade fan shown above uses 170 watts at high speed. These wattages may not indicate your electricity usage because you may run the fan at lower speeds to be quieter.

Almost all window fans have three speeds, some models allow the window screen to remain in, and some are “electrically reversible”, to blow air in or out. Window fans with thermostat control measure the inside and outside temperatures and go on when the outside temperature is cooler than the inside temperature. To use these you must leave the window open during the day, which allows warm air to flow through them into the house. If you have fans that do not have thermostat control you can leave the windows closed with the fans removed or cover the fans with the plastic cover that is provided with some fans, or cover them with a make-shift plastic cover. With the fans covered, watch an outside thermometer to know when to turn them on. There are 10″ weather resistant box fans with thermostat control that can be used as window fans. Their advantage is that they are lighter so they are easier to put in a window opening.

There are problems with using window fans: rain can be blown in, you may hear too much traffic noise, and if you can’t use screens with your fans, insects and pollen may enter. Also, opening the first floor windows will raise the risk of crime. If you leave the fans in the windows all day uncovered, warm air will flow in through them. To prevent insects from entering, you could build a frame of 1″x 4″ pressure treated boards, fasten it to the outside of your house and staple a screen on to it.

Use and care manuals warn that it is unsafe, but not forbidden to use an extension cord, so try to use window fans in windows close to electrical outlets. Never use a very old cord or a thin, low-wattage cord designed for lamps. Both of these present serious fire hazards. See, Portable Fan Electrical Safety

Window fans are not designed to prevent burglars from entering, but if mounted in a double hung window, you can make the window opening hard to enter. First, secure the lower sash tightly above the window fan. On each side of the sash, drill a hole through the upper and lower sashes to allow a 16p nail to snugly fit in, to hold the sashes together. These will hold the lower sash securely in place and they can be removed without using tools. The fan can probably be fastened strongly to the sash above and to the sill below using braces from a hardware store.


Energy Tips for Using Window Fans

    • Cool a large room with window fans by creating cross-ventilation, using either one or two fans. With two fans, mount them on opposite sides of the room with one blowing in and one blowing out. The fan that blows out must be an electrically reversible window fan, you can’t simply turn the fan around. To use one window fan, mount it in a window and open a window on the opposite side of the room and set a stand fan next to that window to blow air out.
    • You can use less air conditioning during the day by running a fan all night long the night before. Leave open a window on the opposite side of that floor to create cross-ventilation. Much of the heat energy stored in the walls, floors and ceilings will be released into the air and escape from the house.
    • If your home is two-story or three-story, use at least one fan to draw in air on the first floor and open a window on the top floor for it to escape. This allows the hot air in your home to rise to the top floor to escape, taking advantage of the “balloon affect”. This will create greater airflow. Try using a window fan in the open window on the top floor to blow out air, and check if this creates a noticeably stronger breeze.
    • If you use fans in the evenings to bring in cool air, it will be slightly cooler if the windows are on the east or north sides of your home. In the early mornings the air temperature isn’t much different on different sides.
    • On cool evenings, use a window fan in a window near where you are sitting (or place a stand fan next to the window). It will cool you with a breeze and also lower the temperature in your home.
    • To cool a room rapidly on cool evenings, close the door to the room, run a window fan or box fan to blow in air and open the window farthest from it to give the air the longest possible path through the room. If the room has only one window and it is a double hung window, open its upper and lower sashes and put an 8″ or 9″ dual blade window fan under the lower sash. This will not cool as well as opening two windows because the path is much shorter. If the room has only one window and you can leave the door open, it would be more effective to use a 20″ single blade window fan or a 20″ box fan than to close the door and open an upper and lower sash of the same window. A 20″ single blade window fan and a 20″ box fan each create much greater airflow than a dual blade window fan.
    • If you use a window fan for exhaust in a double hung window, it will be more effective if you mount it to the top of the window opening because it will exhaust warmer air. This will also allow a better view through the window. You could build a 4″ wide shelf to rest it on.  If the upper sash will not open, it is probably painted shut on the inside. Cut through the paint with a utility knife and pry it open with a stiff putty knife.

Cool Your Home Using Many Types of Portable Fans

You can create enough breeze to feel cool anywhere if you use the ideal fan for that area. Have many types and choose which work best in every part of your house:  box fans, floor fans, stand fans (pedestal fans), table top fans and clip on fans.

Box Fans

use fans in place of air conditioning

20″ Box Fan

Box fans are large, inexpensive, relatively powerful fans that rest on the floor to circulate the air in the house. Most models have three speeds. They run quietly at low speed and create a high airflow at high speed. The 20″ models create airflows of over 2000 CFM (cubic ft. per min) at high speed. Most models should not be used in windows because they are not rain-resistant.

Box fans are much more popular than stand fans because they are much less expensive, easier to carry from room to room, and easier to store when the heating season is over. Most have 20” blades, which gives them greater airflow than stand fans, but they need greater airflow to cool as well as stand fans because they blow the air close to the floor, where you don’t feel it as strongly, and they cannot be tilted upward, as can floor fans. There are 10″ rain resistant box fans which can be used either as window fans or set on the floor. These are lighter in weight than window fans so they are easier to put in a window.

Floor Fans


14″ Floor Fan


High Velocity Floor Fan – 20″










Floor fans are large fans that rest on the floor. They basically have greater airflow than any other type of portable fan. They cool more effectively than box fans because they can be tilted upward to aim the breeze toward your upper body.

Floor fans are available in a very wide range of sizes, from models with small 9″ blades that produce only about 300 CFM to models with 20″ blades that produce 5000 CFM. The largest stand fans produce about 3000 CFM.

The maximum airflow is not given for most models but those that produce very high airflow may be labeled as “20 inch high velocity floor fans”. The size of the fan is the best way to estimate its airflow relative to others, and also its weight. The weight should be given where the fan is shown on the website of the retail store, such as Lowes. The largest floor fans available at most stores produce airflow of about 3000 CFM.

Stand Fans (Pedestal Fans)

fans instead of air conditioning

18″ High Airflow Stand Fan

Stand fans, also called “pedestal fans”, are mounted on adjustable-height stands. They can be more effective than floor fans or box fans because they create a breeze at chest level where you feel it more strongly, and because air flows farther at a higher level. Many are designed to continually oscillate about 80º to cover a large area. Their maximum airflow is limited by the size and weight of their base.

Stand fans with high airflow rates and heavy bases are not popular, largely because they are harder to move around the house. The most popular models have a light-weight disk base and 16” blades that produce about 1100 CFM. This is about half the airflow of the typical box fan. Models with heavy disk bases may have 18” blades and produce about 2000 CFM. The largest models have large, four-legged bases and produce over 3000 CFM. These can create breeze for an entire floor. They are not popular, partly because they are harder to store, since they are heavy and take more storage space. Oscillating stand fans are ideal for using next to a window air conditioner to circulate its cold air throughout the room.

Tower Fans

42″ Tower Fan

Tower fans are tall, narrow fans that are shaped like a tower and have no blades. In place of blades they have a long, thin drum with many small wind vanes attached. The drum rotates within an outer casing and the wind vanes throw out air from the top of the fan to the bottom of the drum. The outer casing has an opening that lets out the air and directs it. The most popular models range from 3 ft. to 4 ft. tall. They are quieter because the rotating drum is in a casing and because the breeze blows from all along the length of the drum.

Tower fans are quieter and more stylish than other large fans. Most models oscillate, that is they rotate continuously back and forth, blowing the air in different directions. Because of these features, tower fans are very popular, in spite of being the most expensive type of portable fan. They are good for bedrooms because they are quiet and take up less floor space. Their airflows range from less than 1000 CFM to over 3000 CFM. This is about the same as the range of airflows of stand fans. Some models have a feature called an “ionizer”. This allows the fan to electrically remove dust and smoke from the air as it passes through them.

12″ Table Top Tower Fan

Table top (desktop) tower fans are typically about 12″ high. They are quieter and produce higher airflows than other table top fans, so they are good to set on a table or desk to cool you while you work. Many models produce about 400 CFM. Their airflows are usually not given on the packages or the websites.

The energy efficiency of tower fans is hard to compare to that of stand fans because the manufacturers of each type seldom give the wattage used by their products. However, tower fans that have ionizer features are much less efficient than those that do not, because ionizers use much electricity.

Table Fans

7″ Table Fan

Table fans, also called table top fans, range in size from fans with 4″ blades that you set close to you on a desk or table, to models with 12″ blades which can move air across the room. The smallest models have airflows of about 160 CFM and the 12″ models have airflows ranging from 400 to 900 CFM. The smallest models are probably the most popular. They cool you fairly well and some can be plugged into your computer while you work. These are called “usb fans”. The smallest models are the most energy efficient type of fan because they can cool you as well as larger fans if you are sitting at a desk or table, while using much less electricity. There are oscillating models and other features available such as three speeds.

As stated above, there are also table top tower fans. These are normally about 12″ tall and produce about 400 CFM. They are quiet and powerful and take up less desk space than table fans that produce this much airflow.

As mentioned, when choosing a fan of any type, the maximum airflows are normally not printed on the boxes, but a few of the manufacturers give them in their websites. You can roughly estimate the maximum airflow of a table fan by comparing its blade diameter to that of larger and smaller models. Also, the weight is often given on websites and the heaviest fans tend to have the highest airflows.

Clip On Fans

6″ Clip On Fan

Clip on fans are very small fans that clamp onto the edge of a desk or table, so they don’t take any space. They are quieter than most table fans because most table fans make a little noise by vibrating against the table. Many are battery powered, which makes them very easy to move around the house.

Most clip on fans have 5″ or 6″ blades and some are smaller. Their airflows are seldom given on their packages, but you can roughly compare the airflows of different clip on fans before you buy one by comparing their blade diameters and comparing their power sources. For example, 120-volt clip on fans probably have the highest airflows and clip on fans powered by double A batteries probably have about the lowest airflows. They may be powered by 120-volt or 12-volt current, or by two D Cell batteries or by two double A batteries. Some are powered through a USB charging cable so they can be charged by a laptop, desktop, or USB transformer.


Energy Tips for Using Portable Fans

Outdoor Thermometer

You can use fans in place of air conditioning when the temperature is not too hot if you own a good variety of portable fans know a lot about how best to use them.

    • Own at least three stand fans. If you own them you are likely to use them in almost every room of your home.
    • Mount an outdoor thermometer outside a window where you see it from inside and mount an indoor thermometer nearby, to compare the temperatures. When the outside air is cooler you can open windows and blow in air with a fan or you can open many windows and not use a fan.

Outside thermometers are sold at garden stores, hardware stores, and in garden departments of home centers. You could, instead, mount a thermometer inside which has an inside and an outside temperature sensor. These are available at many hardware and home centers. Do not mount an outside thermometer or a temperature sensor bulb where it will be exposed to direct sunlight because the readings will sometimes be too high.

    • When the outside air is cooler than the inside air, use window fans to blow in air to lower your home’s temperature.  A window fan is more effective if you open a window on the opposite side of that floor to create cross-ventilation, and even more effective if you use it on the second floor and open one or more windows on the first floor on the opposite side of the house. This will cause the air to follow a long path, cooling the air in much of the house. Do not open any other windows on the second floor because most of the air would enter through it and very little would enter through the first floor window. Warm air moves upward due to the “chimney effect” so it is not effective to run a fan in a first floor window and open a window on the second floor.
    • If the fan runs through the night you will need less air conditioning the next day because much heat energy will have escaped from the floors, walls, and ceilings during the night.
    • Daily Timer

      When the outside air is cooler than the inside air in the early morning,  turn on a window fan to blow in the air and use a daily timer to shut it off in late morning after you have left.  A daily timer is plugged into the outlet where the fan was plugged in and the fan cord is plugged into it. Use a heavy duty model, not one designed for a table lamp. You will need less air conditioning in the evening because heat energy will escape from the floors, walls, and ceilings while the fan is running. A thermostat-controlled window fan could also be used. These measure the inside and outside temperatures and turn the fan off when the inside and outside temperatures are similar. There are window fans available which close a door when the fans turns off to stop air from entering.

    • When the outside air is cooler than the inside air, cool a single room by opening  a window in that room and using a window fan or a floor fan set next to the window to bring in air to cool the room.
    • If the outside air is only slightly warmer than the inside air when you go to bed, open at least two upstairs windows. Before long the outside air will be cooler than the inside air and warm air will flow out of the house. If there is air leakage around doors and windows, air will enter on the first floor or basement and warm air will flow out through the windows you opened due to the chimney effect. If there is no significant air leakage, air will enter through one window and leave through another, especially when the wind blows. The house will loose heat energy throughout the night and as a result need less air conditioning the next day.
    • When the outside air is cooler than the inside air, open a window and run a high airflow stand fan next to it to blow in the cooler air if it is not practical to use a window fan. A window fan brings in more air but you must either set it in the window each time you use it, or leave it in and let warm air will flow through it into the house, and allow a risk of burglary. Also, you can turn a stand fan around to reverse the direction of airflow. This gives you the choice of blowing in cool air to cool the room or blowing out warm air to make the whole house slightly cooler. If the screen will be closed, use a relatively high airflow stand fan because the screen resists airflow, so much air will flow around the fan to avoid passing through the screen.
    • When a window fan is running, close the windows next to it. If left open, some of the air drawn in by the fan will flow out through these windows instead of cooling the whole room.
    • Use an oscillating stand fan next to a window air conditioner to circulate its cold air throughout the room.
    • Raise the thermostat temperature by a few degrees and check if any of the rooms you are using at that time are uncomfortably warm. The temperatures may be slightly different in each room. If a room is too warm, use a large stand fan or large floor fan to blow air into it from a cooler room.
    • Leave open the door to the basement (if this is safe) and run a stand fan at the top of the basement stairs to bring the cooler air from the basement into the first floor. The basement can be 20 degrees cooler than the first floor. Mount a large outdoor thermometer in the basement where you can read it from the top of the basement stairs so you know when to turn on the fan. You could instead run a very high airflow stand fan at the bottom of the stairs to blow up cool air. If it is unsafe to leave open the basement door you could make a make-shift chain latch to secure the door 6″ or 8″ open, and run a large floor fan or stand fan on the first floor, next to the basement doorway.
    • Use a high airflow floor fan at the rear or side door to exhaust the home’s air when the outside air is cool. Each window you open will allow air to enter, creating a cool breeze, so you can open a window in the room you are in to cool the room and enjoy a breeze. If you close the doors to the rooms that aren’t occupied air may flow slightly more forcefully through the house.
    • If you have transoms that don’t open, restore them to working order by cutting the paint around their edges. They were designed to allow air to flow through the house with the interior doors closed and the windows open. In  rooms you want to cool with window fans with the doors closed, open the transoms and a window in each room.
    • If you can’t leave your exterior doors open in the evenings because they have no screen doors or because you need security doors, install them. If you open two exterior doors when the outside air is cool, the warm air in your home will flow out, and more rapidly when there is wind. Opening the doors is much easier than opening many double hung windows, which would be necessary to cool the home as rapidly.
    • Open one or two exterior doors on cool evenings and use a large floor fan or a large stand fan next to one of them to blow out the air. Open a few windows, and those rooms will cool the fastest.
    • Buy a large stand fan or a large floor fan for your porch if you would sit there in the evenings and turn off your air conditioning. It should be the highest airflow model of that type available. The largest stand fans rests on a four-legged pedestal and deliver about 3400 CFM. The largest floor fans deliver about 5000 CFM. If the fan will be plugged into an outlet on the porch or on the outer surface of an exterior wall, the receptacle must be GFI, as used in kitchens and bathrooms. If it is not, replace it with a GFI receptacle. Also, check how much amperage is being used by the circuit so a large fan doesn’t overload it. To check, turn off the circuit’s circuit breaker and see which appliances, lights, etc. go off. If the circuit breaker has 15 printed on it, for example, the circuit allows 15 amps. If  you have a 10 amp window air conditioner plugged into that circuit, and other things, it may not have enough amperage. You may be able to run a long extension cord from the fan, around the house, to another outdoor outlet.
    • If you don’t use window fans because you must remove them when it rains, use waterproof box fans. Their disadvantage is that unlike window fans,  they block the view.

Using Portable Fans In the Bedrooms:

    • Sleep with a stand fan blowing breeze over the bed. A high airflow stand fan running at a low speed is quieter than a low airflow model running at high speed, creating about the same airflow.
    • Use a large, oscillating tower fan. They are the quietest type of fan and they take up less space than a stand fan. When sleeping, turn off the oscillation and aim the fan to blow air over the bed.
    • If you cool a bedroom with a window fan while you sleep, control it with a daily timer. These are simple to use and inexpensive. The fan cord is plugged into it and it plugs into an electrical outlet. You could, for example, set the timer to run the fan for two hours before going to bed to cool the room and until midnight. Set it to turn off the fan for quieter sleeping. With a daily timer you can check the weather forecast each day and then set the timer. Buy a heavy duty model, not one designed for a table lamp.
    • If you sometimes fall asleep with a fan running when you meant to turn it off, buy a “wireless remote control appliance switch kit”, to turn off the fan using a remote. A component is plugged into an electrical outlet and the  fan cord is plugged into it. The kit shown allows you to control five appliances from either of two remote switches, so you can turn off your fans and lamps from your bed. They are sold at home centers and online.
    • If you have transoms above the bedrooms doors, repair them if necessary and open them all night when the outside air is cooler than the inside air, with the bedroom doors closed. Either open all the bedroom windows or run window fans in one in each bedroom. If there is a window in the second floor hallway, you could run a reversible single blade window fan in it, set on reverse to blow air out, and close the bedroom doors with the transoms open and a window open in each bedroom. This would allow the bedrooms to be quieter.

In the Home Office:

    • The quietest way to create a strong breeze at the desk is to use a 48″ tower fan, not oscillating. For extra breeze, and blowing air at your face, use a clip on fan at your desk or table.
    • Use a 12″ table top tower fan at your desk or table. They are quiet, powerful and take little desk space. You feel breeze from a different direction than when using a tower fan or a stand fan in the office.

In the Kitchen:

    • If your floor space is limited use a large tabletop fan (12″) on the table or on a counter. If your floor space is not very limited use an oscillating stand fan adjusted to a height higher than the counters.

In the Living Room:

    • Use one or two high airflow oscillating stand fans, floor fans or oscillating tower fans.

In the Workshop:

    • Use a large oscillating stand fan, adjusted to be higher than the work bench.

In a Finished Attic:

    • When the central air conditioning is turned off, the air temperature in a finished attic would be higher than the outside air temperature most of the time. One or two powerful window fans could be used to lower the air temperature in the attic by blowing out the hot attic air, even if the outside air is somewhat warm. This would also make the air on the floor below a little cooler. If there are two windows, put a single blade window fan in each. One must be reversible and set to blow out the air for cross ventilation. Single blade window fans with 20″ blades create much greater airflow than dual blade window fans, which have two small blades. Also, use an oscillating stand fan to create a comfortable breeze.


Portable Fan Electrical Safety

When Using an Extension Cord:

  1. Try to avoid using extension cords because they are never 100% safe. You may be able to avoid using them by buying fans with long cords or by installing new outlets.
  2. If you must use an extension cord, no not use a “lamp extension cord”. These have thin, 18 gage wire which is only safe when used for one lamp. They are labelled 18/2 or 18/3. If used for a fan, the cord could overheat and start a fire (18 gage wire is thinner than 16 gage wire).
  3. If an extension cord must be used, buy a new cord. A cord you have used before may be damaged or may not be long enough to put it completely out of the way. If the cord is too short, you could trip on it or damage it by stepping on it. Also, a new extension cord will have the gage written on the package, which will prevent you from using a lamp extension cord.
  4. Never run an extension cord under a rug or carpet. People stepping on the carpet could damage the cord.
  5. Never use an extension cord in wet areas such as bathrooms.
  6. If a fan will be used close to a wall but far from the nearest outlet, you could install a new outlet using wire channel,

    Wire Channel Outlet Box and Cross Section

    and you can do this yourself if you are handy. A wire channel outlet is mounted to the surface of a wall, and wire channel is mounted along the baseboard leading to it from another outlet. Wire channel is commonly referred to as “wiremold”, but wiremold is actually a brand name. A do-it-yourselfer can install a wire channel outlet by following the instructions on the package and watching a video that shows how to do it.

  7. If a cord is used where people walk, cover it with a rubber “cord protector” or “overfloor cord protector”. These are sold at hardware stores and home centers.

Whole House Fans

Whole house fans draw air forcefully out of the house through the attic floor. Of the many types of fans, they are the largest. They push out the warm attic air through the attic vents, which draws outside air into the home through open windows. This cools the home when the outside air is cooler than the indoor air. Large fans can purge a house of hot air in two to three minutes. Some whole house fans have insulated shutters that close automatically when the fan is not operating.

    • If you run a whole house fan all night long, the walls, floors and ceilings will lose heat energy into the cooler air so less air conditioning is needed the next day. If you open only the windows in the rooms you are using, these rooms will become cool almost immediately and you will feel a comfortable cool breeze.
    • There are two types of whole house fans that are mounted to the attic floor: belt drive fans and direct drive fans. Belt drive fans are generally quieter but more costly, but the more expensive direct drive fans are also quiet. To avoid cutting a large hole in your attic floor you could install a ducted whole house fan. These are “remotely mounted”, i.e. they are mounted nearby, normally to the attic ceiling rafters above the opening in the ceiling. They are very quiet, but much more expensive than the other types of whole house fans. All three of these types of whole house fans are available in a wide range of airflows for homes small to large.
    • If you use a fireplace, you must open several windows when using a whole house fan to avoid drawing air down the chimney, bringing soot into the home.
    • Your attic should have as much attic vent area as required by the fan’s manufacturer, or the fan will move less air out of the house. The air pressure in the attic will become too high, forcing hot attic air down into the living area and causing a push on the roof structure, which could be harmful.
    • The required attic vent area is given in the fan’s installation instructions and on the manufacturer’s web site. A rule of thumb is to have 1.0 square foot of unobstructed attic vent area for each 750 CFM of airflow, but most vents are not unobstructed. Vent screens with small holes significantly restrict the airflow through them, so if you have them you must use a smaller vent area for the calculation. One estimate is that if you have a 1/16″ screen, use half of this vent area to determine the capacity of the fan. Louvers and roof vents are also not unobstructed so you must reduce their vent area for your estimate. Many louvers and roof vents are stamped with a rating of their free open exhaust area. If you can’t read it, find a comparable model on a store web site and use that free open exhaust area.
    • If you want to buy a fan that requires more attic vent area than you have, you could cut additional soffit or gable vents (wall vents), and/or install one or two roof turbine vents, and/or install several roof pot vents. If you have a window in your attic, you could, instead, leave it open for the summer months. You may need very much more attic vent area, requiring several roof pot vents or several roof turbine vents (you probably already have gable vents). Roof turbine vents and roof pot vents are normally the most effective. Roof turbine vents rely on wind to be fully effective but they vent air when there is no wind.
    • To save energy you could replace the fan’s switch, which is normally mounted below it on a wall, with a mechanical timer switch, to turn off the fan after about 4 hours. This would also prevent the fan’s noise from waking people early in the morning.
    • Codes now require that you install a separate electrical circuit for any new whole house fan. To make a new circuit, run a cable from the electrical panel to the fan. The cable could be run from the basement along the outside of the house, or through the chase way that boxes in the plumbing stack. The chase way runs from the basement to the roof. The stack is a large pipe that is an air vent from the roof to the kitchen and bathrooms, and a drain below them.

30″ Belt Drive Whole House Fan

30″ Direct Drive Whole House Fan

Ducted Whole House Fan



















    • In cool evenings, can cool the home faster than whole house air conditioning.
    • Can increase the property value of the home
    • Purifies the home’s air by replacing it
    • Quieter than window air conditioner, good for sleeping
    • Creates comfortable breeze, especially in rooms with open windows
    • Uses electricity more efficiently than portable fans


    • All whole house fans that are mounted to the attic floor are at least slightly noisy  due to air flowing rapidly through them, and some less expensive direct drive fans are noisier.When sleeping with the bedroom door open, this bothers some people.
    • Requires much labor to install. Can only be done by experienced do-it-yourselfer. Requires installing cable from circuit panel to fan. Switch may require wiring but wireless controls are a feature on some fans. Most models require cutting attic floor joist and framing out a 30″ x 30″ or 36″x 36″ opening.
    • On rainy days it will raise the humidity in the home to near 100%. When the pollen count is high, pollen will enter.

If your home is mid 20th century, it may have a whole house fan that is not working. It will be above the hallway near the center of the house. These were built into many homes in the days before central air conditioning. You should be able to fix it yourself. If the fan doesn’t run, the motor is probably burned out. The original motor cannot be purchased, but these old whole house fans are belt-driven, so any motor of that horsepower can be used to repair it.

Ceiling Fans

52″ Ceiling Fan with LED lighting

Ceiling fans can help you use less air conditioning by creating a breeze, allowing you to turn down or turn off window air conditioners in the rooms the ceiling fans are in or turn down or turn off the central air conditioning. They do not lower a room’s air temperature.  It has been estimated that a correctly-sized ceiling fan can allow you to raise the air conditioning thermostat setting by as much as 4°F with no reduction in comfort. Sleeping with a ceiling fan running allows you to use less air conditioning because the breeze removes a layer of warm air from the blanket so that you sleep cooler.

A ceiling fan uses only about as much electricity as an incandescent light bulb. The largest models use about 85 watts and the smallest use about 50 watts. The right fan will beautify almost any room, increasing the property value of your home.

Energy Tips for Buying, Mounting and Using Ceiling Fans

Energy Tips for Buying Ceiling Fans 

    • To turn off and turn down your air conditioning as much as possible, install ceiling fans in all of the rooms where they are normally used: only the living room, the bedrooms and the sun room. Installed in other rooms they would appear out-of-place and may not increase the property value of your home.
    • If the room must be quiet, choose a fan that is described as “designed for quiet operation”. If possible, listen to the fan in operation before you buy it. Fans with a higher number of blades are designed to move the same amount of air while rotating slower. They are a little quieter because they run slower. The least expensive fans tend to be a little noisier, but not all of them. Buy a larger size than necessary so you can run it at low speed because all fans are quiet at low speed.
    • Buy fans that are at the top end of the manufacturers’ range of recommended sizes. A larger fan will often use less electricity to create the same airflow because you will run it at a slower speed, for example, a large fan running at medium speed may create the same airflow as a smaller fan running at high speed. It will also be quieter at medium speed than a small fan at high speed. A table of recommended sizes will be printed on the fan’s box. A typical table is shown below.
For Rooms Up ToUse Fans of Size
80 sq. ft.30"- 39"
144 sq. ft.40"- 49"
300 sq. ft50"- 60"

Almost all ENERGYSTARTM qualified fans are 52” or larger, which shows that large fans are the most efficient. Size 52” may be the most popular. The airflow efficiency in CFM/watt is given on the label of all fans and may be given on the website of some retail stores that sell the fan. The efficiency is the product of the fan’s size, the blade pitch (the angle of the blade), the number of blades, the shape of the blades, and the efficiency of the motor.

Compare the maximum airflows of the fans you are considering buying. Fans of the same size can have very different maximum airflows because they have different blade pitches, numbers of blades, motor speeds, and blade shapes. The maximum airflow is given on a fan’s label on the box, in CFM (cubic ft. /min). It may also be given in a fan’s specifications, which is on the website of some retail stores that sell the fan.

    • A ceiling fan that is controlled by a remote may use less electricity per month than one that is operated by a pull chain because if a fan has a pull chain you may not always turn it off when you leave the room.
    • For bedrooms, buy ceiling fans that are large for the room size. You can run them at a lower speed to create the same airflow and they will be quieter.
    • Some manufacturers advise you to mount two fans in a room that is greater than 18 feet long.
    • Some very large ceiling fans must be oiled periodically. If you are afraid you wouldn’t oil it, don’t buy one of these models.
    • If it will be installed in a bedroom, buy a model with a remote so you can turn it off while in bed to save electricity.
    • If there are loose papers that would be disturbed by a strong breeze, buy a fan that is larger than the manufacturer’s recommended size and run it at low speed.

Energy Tips for Using Ceiling Fans 

    • If you use many ceiling fans, post a note next to the air conditioning thermostat control, such as:


    • If you use ceiling fans in the winter and in the summer, post a note on a wall to remind you to reverse the fans’ direction. For example:


    • Check that your ceiling fans rotate counter clockwise in the cooling season. All ceiling fans rotate this way to push air downward to create breeze. If a fan is rotating clockwise in the cooling season, reverse its direction by sliding a switch on the side of the fan or by pressing the “reverse” button on the remote. If the fan has neither of these it may have a switch on its top surface or you may have to remove a small cover plate on the bottom to access the switch.
    • Use ceiling fans to draw in cool air in the evenings. If you lower your upper sashes, slightly more air will be pulled in than lowering the lower sashes.
    • When you run ceiling fans with the central air conditioning operating, raise the thermostat temperature a few degrees so that the air conditioner runs a little less.
    • Do not run the fans in winter, in reverse direction unless the ceilings are unusually high. Fan manufacturers and utility companies recommend that you run them in winter in reverse direction to remove the layer of warm air at the top of the room, but if you don’t have unusually high ceilings, the effect is almost insignificant and there are problems with doing it. First, people very often forget to reverse the direction when the cooling season starts, and the fan runs in the wrong direction all summer. Second, it shortens the life of the fan and may cause the blades to loosen sooner. Some people stop using ceiling fans when the blades become loose because they don’t know how to tighten them.
    • Never leave ceiling fans running when no one is in the room. Their motors are very hot and radiate heat into the room, slightly raising the room’s temperature. Several ceiling fans running in a home can raise the home’s temperature by 1º, which adds to the cost of air conditioning. In addition to this, the cost of running several fans all day adds to the electric bill.
    • If a fan is using 60-watt incandescent bulbs, replace them with three 13-watt mini-CFL bulbs, which are designed to produce about the same amount of light. Incandescent bulbs convert about 80% of the electricity used into heat, which increases the need for air conditioning in the room.
    • If you sleep with a ceiling fan running, it will cool you better if you use a very loose weave blanket.
    • If you let your bedroom ceiling fan run all night because you don’t get out of bed to turn it off, convert it to remote control. A “ceiling fan remote kit” can be used to convert most ceiling fans. The remote can be supported in a wall bracket next to the light switch, allowing you to turn on the fan when you enter the room or carry it with you. The kit includes  a remote, a wall bracket and a receiver that you install in the canopy of the fan or in the ceiling next to the fan. The kits are sold at most stores where fans are sold.
    • If the blades of a fan are higher than about 8 ft. above the floor, replace the  downrod with a longer one to lower the fan to about 7 ft. above the floor. The closer a fan is to the floor, the more effective it is in the summer. If a fan is used in the winter, it is most effective if mounted close to the top of the room. A downrod is a pipe that supports the fan’s motor and blades, with wires running through it. Most fans have short downrods, which support them at 12” to 14” from the ceiling. You can replace any downrod with a longer one, but only if there is enough extra wire in the electrical box. The installer may have left extra wire to allow the fan to be lowered. It is unsafe to extend the wires by joining them to new wires inside the downrod. Downrods are sold at most stores where ceiling fans are sold and these can be used for almost all ceiling fans.
    • Mount one or two ceiling fans in your porch if this would allow you to spend more time there with your air conditioning turned off. They must be labeled, “inside/outside” or “for wet locations” and should be 60” or 52”.
    • If you have a ceiling fan that you don’t use because it wobbles, repair it. Fans wobble either because the blades are loose or because they are out of balance, that is, one or more blades are too high or too low. If the blades are loose, tighten the screws. You must use a size #3 Phillips screw driver to make the screws tight enough. This is larger than the common Philips screw driver, which is size #2. To balance the blades, check that the distance from the tip of each blade to the ceiling is the same. If the tip of a blade is high, tape a weight, such as a large steel nut onto it. If the tip of a blade is slightly low and the blade is connected to a brace with three screws, loosen the screws and slip in a shim or piece of cardboard to slightly raise its angle.
    • If you have a ceiling fan that you don’t use because it shakes badly or it wobbles and you can’t fix the wobbling, it may not be firmly mounted. The fan’s mounting bracket is mounted to an electrical box and the electrical box may not be firmly mounted. To check, lower the canopy to see the mounting bracket and electrical box. Shake the fan and check if the electrical box moves. Often, an electrical box designed for a ceiling light is being used, and this is unsafe. The screws that attach the mounting bracket to it are thinner than those used with ceiling fans, and the box may not be strongly mounted. Nails may have been used to mount the box instead of screws. The vibration of a ceiling fan may loosen this type of box.

      Fan Box Mounted to Brace

Electrical boxes designed for ceiling lights are rectangular metal boxes with an opening of about 2” by 4”. If your fan is mounted to one of these, you should replace it with a ceiling fan box. If you cannot do this because the wiring in it is very old and could break if you replace the box, you may be able to mount the mounting bracket directly to the ceiling. If your ceiling is made of plaster with wooden lath strips (pre-1960’s) you can screw the mounting bracket to lath strips.

The fan may be loose because it has a fan box that is screwed to a brace, and these screws came loose from the vibration. All fan boxes are mounted to braces which are attached to the joists on either side of the fan box.

    • If you have a ceiling fan in a large room, it should be a 52” fan. If it is smaller than this you may be using more air conditioning than necessary. Replace it with a 52” fan. Fans of the same size can have very different maximum airflows. If you want maximum airflow, check the airflows of the fans. It should be given in CFM’s on the box or on the website of the retail store that sells the fan.
    • Check if any of your ceiling fans must be oiled periodically. The large majority of fans sold today have “sealed bearings”, which do not require oiling. Some high-end ceiling fans require oiling, as do many very old ceiling fans. There are several signs that a fan has gone too long without being oiled: the blades are slightly hard to turn by hand; the fan is slightly noisy; the fan has a burning smell.

Fans that require oiling are usually made of cast iron and are very heavy. These may have an oil port and an oil reserve below the motor, which you access by removing plates, or they may have an oil port at the top of the motor. It is best to check with the fan’s manufacturer for instructions on oiling these fans. If you have no instructions, use 10- or 20-weight non-detergent oil. The oil port is a very small hole with “oil” stamped next to it. After adding oil, run the motor at low speed for a few minutes to distribute the oil. If run on high speed it may sling the oil around the room.

    • If a ceiling fan that was not designed to be oiled has blades that do not turn freely by hand and do not coast, or if it makes noise as the blades spin, the bearings may need to be oiled. This is more likely if the fan has been running in dirty, dusty air. Use a 10 or 20 weight non-detergent motor oil. WD40 can be used to clean very dirty bearings, but after using it you must oil the bearings with 10 or 20 weight non-detergent motor oil.

On some fans you must disassemble the motor to access to the bearings. There are bearings at the top and bottom of the motor that should be oiled. Bearings that are particularly dirty or worn can be replaced. The motor has to be disassembled, in which case they can be pulled or punched out. Replacements are available at motor and bearing shops.

Energy Tips for Mounting Ceiling Fans

    • Ceiling fan installation instructions may require that you use a ceiling fan box, so replace an electrical box that was designed for a ceiling light with a ceiling fan box if possible. In many cases you can avoid replacing the box by securing the mounting bracket strongly to the ceiling with screws. The box must be mounted very strongly because the vibrations could otherwise loosen the box. Also, a ceiling box designed for a light has smaller mounting screws for the fixture mounted to it. Homes built in recent decades may have their ceiling lights mounted to large, round plastic boxes that are designed for lights or fans. “For Ceiling Fan Use” is stamped on them.

There are ways to make a ceiling box stronger without replacing it. For example, if an unfinished attic is above the ceiling box, you could nail a 2×4 between the two nearby joists to support the electrical box. If the ceiling is made from plaster with lath strips you could screw the mounting bracket to the lath strips. If the ceiling is made from drywall you may be able to mount the mounting bracket to it using very large toggle bolts. If you drill into drywall to use toggle bolts, be very careful not to drill into an electrical cable.

    • If the ceiling is very high mount a down rod between the ceiling and the motor to lower the blades to 7 to 8 ft. above the floor. This creates the strongest airflow. Ceiling fans are less effective at heights above this.  Down rods of many lengths are available wherever fans are sold. The instructions for assembling a fan show how to assemble it with a longer down rod (most fans are installed with a short down rod).
    • Ceiling fans must be mounted with their blades at least 7 ft. above the floor for safety. If the ceiling is too low for 7 ft. blade clearance, check if it is high enough for “flush mounting”. This is removing the standard short down rod and mounting the motor and blades a few inches higher. Many ceiling fans offer this option. It may be better to do this than to buy an inexpensive flush mounted ceiling fan. These fans can be of low quality and have lower airflow.

Ceiling Fan with Standard Short Downrod

Flush Mounted Ceiling Fan

Ceiling Fan with Long Downrod











    • When screwing a blade onto the motor, be careful to hold the blade at the correct angle or you could strip the threads in the motor. The motor is aluminum so the threads are not hard to damage. This would be difficult or impossible to repair.  Put in the screws carefully with a screwdriver, not a power tool.
    • If the fan will be controlled by a wall switch, a dimmer cannot be used. Only a ceiling fan dimmer may be used. A dimmer that is not designed for ceiling fans will destroy a ceiling fan by reducing the voltage to a level that is too low for a fan motor. Also, a ceiling fan dimmer cannot be used with a fan that has pull chain speed control. All pull chains are the fan’s speed control; pull once for high speed, twice for medium speed and three times for low speed. This will destroy the fan because the pull chain speed control reduces the voltage and the dimmer also reduces the voltage. If both were at their low settings the voltage would be too low for the motor. To use a ceiling fan dimmer to control a fan with pull chain speed control, set the pull chain speed control to high speed and cut off the chain.
    • A ceiling fan can be installed on a ceiling with any slope, but if it is greater than about 34 degrees a special mounting cap and down rod must be used. The installation instructions explain this. The mounting cap may have to be ordered from the fan’s manufacturer.
    • A ceiling fan should be mounted near the center of a room to create breeze throughout the room. If the nearest ceiling light is not near the center, mount the ceiling fan at the center, directly under a ceiling joist for support. Use a flat, round electrical box no thicker than the plaster that it will be buried in. One way to power the fan is to run a 14 ga. cord from the electrical box that had supported the ceiling light to the fan, in wire channel mounted to the ceiling.

Metal Wire Channel

Wire channel is commonly called Wiremold, which is a brand name. A do-it-yourselfer can install wire channel by following the instructions on the package. You must make a hole in the canopy and insert the wire channel into the canopy. If you make a hole in the canopy only for the wires, the sharp edges of the canopy could cut them. If there is an unfinished attic above, a 14 ga cable could be run across the attic floor from the electrical box that had supported the ceiling light to the electrical box for the fan, or you could use a standard electrical box mounted to a 2 x 4 that you have nailed between two attic floor joists.


Energy Tips for Coolng Your Home With All Types of Fans 

    • Before leaving your home for the day, close the blinds and draw the curtains on all of your windows. The air temperature in your home is coolest in the early morning and it will rise more slowly if the curtains and blinds are closed.
    • When the evening will be cool, create the “chimney effect” by opening windows on the first and second floors or the basement and first floor. Since heat rises, the warm air in your home will forcefully rise to the highest floor where the windows are open, drawing in cooler air from the lower floor. Open windows on opposite sides of the house so the cool air follows a longer path, cooling more area. If the wind tends to blow in the same direction where you live, open the window on the lower floor on the wall facing the wind. Also, if you leave these windows open all night, heat energy will escape from the floors, walls, and ceilings during the night and reduce the need for air conditioning the next day.
    • If possible, sleep in the basement or put a bed in the basement to sleep on when the weather is hot.
    • Pull down the blinds or draw the curtains during the daylight hours on the windows of the rooms you aren’t using. Heat enters the house through ultraviolet energy even when the sun isn’t shining through the windows. The proof is that the inside of a car becomes warm when the sun isn’t shining on the car. You may want to pull down the blinds or draw the curtains on any windows where sun shines in, even if you are using those rooms.
    • Try to avoid using the oven when using fans to cool the home. When you use it, run the kitchen exhaust fan. This not only removes hot air but also water vapor, to lower the home’s humidity. Also, turn on the bathroom exhaust fans after showering. When the humidity is high it is harder to tolerate warm air and harder to cool your home with fans.

I hope you will take a close look at these many types of fans and buy some of them so you can turn off your air conditioning!