Furnace Turns Off Before Reaching Desired Temperature [DIY Fix]

If your furnace turns on, heats a little bit, then turns off before the temperature reaches your desired thermostat set point, try these simple solutions; the fix might be easier than you think.

Check the furnace filter, duct work, and vents — anything blocking the free-flow of air will obstruct airflow to the heat exchanger in the furnace. And if the heat exchanger gets too hot from lack of airflow and overheats, a safety mechanism will shut off the furnace to protect it.

Problem: Furnace fan was set to ON, but no air was being circulated or pushed through the vents. Also, the furnace would turn ON to the heat setting, but no heat was coming out of the vents long enough to reach the desired thermostat setting of 70 – the furnace would shut off shortly after firing up. What could be causing the problem? Consider these possible culprits:

  1. Dirty filter. Have you checked your furnace air filter lately? Maybe it needs to be changed. Change it each month or 6 months or according to the furnace manufacturer directions.
  2. Blocked airflow. Do you have any intake air vents OR other vents completely covered or blocked off? If the registers (vents) are covered, that will inhibit the flow of air from the furnace and create an increase in air pressure backing up into the heat exchanger, and can trigger the furnace to turn off prematurely.
  3. Thermostat wiring. Did you install a new thermostat lately? Is the wiring correct?
  4. Thermostat setting. Is the thermostat set to “Heat”?
  5. Duct work is wonky or not attached properly. Foil seal the connections to prevent air leaks. In my mom’s house, turned out that the duct work had not been put back together after some construction. Ridiculous. For most people, this will not be your problem.
  6. Furnace powered On? Is the furnace switched “ON” at the furnace and/or breaker? This is something to check when you switch between heating and cooling seasons.

Thermostat Wiring

My friend had just installed an ecobee thermostat (at my recommendation), he assumed that the formerly working furnace was now malfunctioning because of the new ecobee. Fair hypothesis.

He sent me a photo of the wiring. All looked fine at both the furnace and the thermostat.

I asked if he had made any other changes or if her furnace filter had been changed lately. Since the furnace was relatively new, I doubted the filter was the problem. Turned out that the register closest to the furnace had been completely sealed off, and the air being pushed out from the furnace had no where to go, so the furnace was overheating. He removed the sealing foil tape and the furnace could breathe again.

Dirty Filter

Remember to change your dirty old furnace filter. A clogged filter can restrict the air flow to your HVAC system.

A clogged filter limits the ability of your furnace to produce and distribute warm air throughout your home.

Some furnaces even contain a built-in shutoff that kicks into action when the filter gets clogged, in order to prevent an overheated burner. When that happens, the furnace will blow cold air. Filters are cheap and easy to change.

After replacing your furnace filter, restart your furnace. Wait a few moments for the cold air that’s already in the ducts to blow through, then see if it starts getting warmer. If so, congratulate yourself on finding a solution without having to call in the experts. If changing the filter and restarting doesn’t do the trick, here are some more possible solutions.

If you hear your furnace kicking on and off quickly, this can be a symptom of a clogged furnace filter or a blocked heat vent.

Closed Heating & Cooling Vents, Dirty Ducts

Just as a clogged filter can obstruct the air flow and decrease pressure at the blower fan, a blocked vent has the same effect.

Ducts get dirty

Most HVAC systems use a forced-air system, which means the furnace heats and cools air that is circulated through the ducts in your home. The air is pushed into your rooms while the existing room air is pulled in through a separate set of return ducts (cold air return ducts), where the air is heated by the furnace.

  • Dirty Ducts: Clean off your air return duct panel with a rag or remove any dust or dirt with your vacuum’s extension attachment. Periodically vacuum your duct work as far as you can.
  • A blocked heat vent or clogged duct work can prevent air from circulating through the furnace unit, which can overheat the heat exchanger, tripping the limit switch and shutting off your furnace. Obviously, this will prevent your home from heating properly. If this overheating happens often, the electronic “high limit switch” safeguard can fail, at which point the furnace won’t come on to heat your home at all.

How Much Energy Does a Ceiling Fan Use?

Ceiling Fans: Cheap to Run and Help Occupants Feel Comfortable

Does it make sense to use a ceiling fan to cool your home, instead of sticking with your expensive-to-run yet effective-at-cooling standard air conditioner unit?

Do ceiling fans use a lot of electricity? Compared to your Air Conditioner, heck no. Typically, ceiling fans range in size from 36 inches to 56 inches and use from 55 to 100 watts of power to spin. An average 48-inch ceiling fan will use 75 watts. Here is an energy calculator to find out how much electricity your ceiling fan uses

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If you don’t use a room often, you likely don’t need a ceiling fan for that room. The best ceiling fans for your home will complement any decor, increase your comfort in all seasons, and possibly help you save on your energy bill, as long as you choose the most powerful fan you like that has the highest CFM rating possible in the price range you can afford.

If you find several ceiling fan models that you like, and they all have similar CFM ratings, then perhaps make the final decision by comparing the fans’ efficiency ratings — but don’t choose a smaller, more efficient fan if it won’t move enough air to do the job.

Airflow is More Important Than Efficiency

Common wisdom says that a large ceiling fan is far cheaper to run than an air conditioner if you have an older house with poor insulation. If you are comfortable with using fans to cool yourself during hot weather, then you will be able to save energy and money by leaving your AC unit off as much as possible and relying on the breeze generated by a fan.

When I Use Ceiling Fans to Cool Myself, How Much Energy Does My Ceiling Fan Use?

Ceiling fans do not cool the air in the room, remember. If you are not in the same room as the fan, then turn off the ceiling fan. The reason a room feels cooler with a fan circulating the air is because as the air moves across your skin, it evaporates water from the surface of your body, thus providing a cool effect. The temperature of the air, however, remains the same.

Standard Fan Sizing: Airflow and CFM

The amount of air a ceiling fan can move per minute is measured in cubic feet per minute, or CFM. This measurement provides a standard representation of the amount of air a fixture can effectively circulate. The rule of thumb is that you need at minimum 1 CFM per square foot of room area. For example, to determine the square footage of a room, multiply the length times the width of the room: a 5ft x 10ft bathroom = 50 sq.ft. and therefore needs a fan rated to move at least 50 CFM.

Focus on CFM for Actual Comfort and Savings

As mentioned, a fan’s Airflow (or CFM) is by far the most important detail when choosing a fan, and airflow is dependent upon the pitch of the fan’s blades.

blade pitch is the angle of the blade in degrees

The range of energy consumption between 52″ ceiling fans that use the least electricity and the most electricity is roughly 30 to 110 watts. At first glance, that seems like a big difference because mathematically, it means that the most energy hungry fans use more than 3 times as much electricity as the least energy consuming fans. But that isn’t the whole story, because when you look closer at the overall cost of operating either fan on an annual basis, the lack of airflow produced by the less powerful fan is not compensated by the energy savings.

Some Math to Illustrate

Assume that both of your hypothetical 52″ fans are operated 200 days a year, 8 hours a day. So 1,600 hours.

52″ Fan A uses 30 Watts (=.03 kWh)
52″ Fan B’s blades have a greater pitch and uses 110 Watts (=.110 kWh)
Cost of Electricity $.126/kWh (in Ontario on a tier payment contract, 2020)

Fan A = .03 kWh x $.126/kWh x 1,600 h = $6.05 per year
Fan B = .10 kWh x $.126/kWh x 1,600 h = $20.16 per year

Total savings of Fan A over Fan B = $14.11/year…. BUT…

By using the cheapest fan with the smallest motor that moves almost no air, instead of the “energy guzzling” fan, you save a whopping $14.11/year…and yet it is a waste of money, because Fan A fan does not have enough power to do the job and you feel uncomfortably warm all summer long. Which means a wasted $6.05/year rather than a savings of $14.11/year.

NOTE: The ubiquitous adoption of under-powered yet energy-efficient fans is also the reason many experts encourage you to skip the ceiling fan strategy and just use the AC unit.

Variables All Over the Place

You may have heard that if you use ceiling fans and raise your thermostat (you can raise it by as much as 10 degrees without compromising your level of comfort), the result will be a savings of around 10% off your cooling bill.

The problem with making energy saving calculations is that the price people pay for air conditioning varies widely based on:

  • the configuration of the system,
  • the efficiency of said system,
  • the climate,
  • and how cool the house must be in order for one to feel comfortable.

These are all variables that change dramatically from one home to the next. As a conservative estimate, at a minimum, with five adequately powered, so-called “energy guzzling” high-wattage ceiling fans in a home where the cost of air conditioning is around $150.00/month, that household should be able to save 15% of that AC cost by utilizing the five powerful ceiling fans.

Here’s the math to see the cost of operating five ceiling fans per month, at 8 hrs/day:

5 Fan A models x 30 days x 8 hrs x .03 kWh x $.126/kWh = $4.54/mo
5 Fan B models x 30 days x 8 hrs x .10 kWh x $.126/kWh = $15.12/mo

Some studies show that many people who own ceiling fans do not actually lower their thermostat and end up spending more money. These are the people who own under-powered or small ceiling fans with a low CFM rating, that do not move enough air to change their comfort level. Such fans are commonly sold at home centres for less than $150.00. In this example we are not going to change our thermostat, so we end up spending an extra $4.54/month and do not save anything on our air conditioning bill.

Now, let’s calculate how much money we can save if we raise our thermostat by 10 degrees and use the powerful fans to cool us down:

Average cost to run the air conditioner in a summer month = $150.00
Even if you still use your AC but just use it only 15% less, you have ($150 x .15) = $22.50 in savings, and run your fans on high setting for 8 hours a day for 30 days.

Subtract the cost of operating your five fans: $22.50 – $15.12 = $7.38 in savings each month. I bet you can use your AC half the time and save even more.

So when you are in the market for a ceiling fan, make sure you choose the fan that moves the most air relative to its size. The above calculations illustrate the rationale for using less efficient, more powerful ceiling fans in your home. Try the calculations for yourself.

Bottom line: Find a fan you like that has the highest CFM rating possible in the price range you can afford. If you find several ceiling fan models that you like, and they all have similar CFM ratings, only then compare the efficiency rating to help make your final decision.

If you are searching to buy a fan online and the manufacturer does not include CFM details, choose the fan with the widest blade span (52″ and up if that size physically fits. Use your judgment and measure to make sure there is at least a foot and a half distance from the blades to the wall), and choose the fan with the most blades, and/or has blades that are angled sharply to move more air. Common sense stuff.

What Size of Ceiling Fan Do I Need to Cool My Room?

Determining the correct ceiling fan size for a room is important because fans are meant to move a certain volume of air.

So what size of fan works best in your room? If you aim to lower your energy bill and increase your comfort indoors, then choose the ceiling fan that moves the most air — this will be the fan with the greatest CFM rating. Your ceiling fan choice is also constrained by the size (in square feet) of the room in question, the length of the fan blades, the desired energy efficiency of the fan, and of course your preference in fan style and its installation or mounting method.

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For comfort’s sake, find the largest fan that fits your room size, then choose the most powerful fan you like that has the highest CFM rating possible in the price range you can afford.

An average 44-inch ceiling fan, for example, will move 3,600 to 3,700 cubic feet of air per minute.

To install a fan of this size in a small room means that you are buying far more air-moving capacity than is needed, but depending on how hot the room normally gets without a fan, you might need that seemingly oversized fan.

But make sure that the size of the fan will not dominate your tiny room.

The worst case scenario is buying an under-powered or small fan that cannot adequately move enough air to be effective for that size of room.

Room Size (Sq. Ft.)Room Type Recommended Blade Span Recommended CFM Rating
Under 75Nooks, Stairwells, Laundry Rooms, Walk-in Closets, or Small Bathrooms29-36″ Fans1500 CFM
100-256Bathroom, Breakfast Nooks, Utility Rooms, Small Bedrooms, Porches42-52″ Fans3000 CFM
256-400Medium Bedrooms, Kitchens, Dining Rooms, Dens, Patios44-52″ Fans4500 CFM
400+Master Bedrooms, Family Rooms, TV Rooms, Small Garages, GazebosFans Over 50”6000+ CFM
Over 400Great Rooms, Large Garages, Basements, and Open Floor PlansFans Over 62” or Multiple Fans if the Room is Rectangular6000+ CFM each
Fan Sizing Guide Cheat Sheet.

Airflow: Airflow is measured in CFMs (Cubic Feet Per Minute). This is the actual volume of air that the fan is capable of moving on high speed, and is dependent upon the blade pitch and the fan motor. Airflow is the most important point to keep in mind for comparing ceiling fans, as it describes how effectively the fan will function. The most powerful fans on the market will move around 10,000 CFM, while the average fan only moves about 4,000 CFM. You will find a dramatic difference in your level of comfort when sitting beneath the two fans.

Electricity Use: The amount of electricity a fan uses is measured in watts, and you are likely already familiar with the energy consumption of the average light bulb, also measured in watts.

As you compare fans, you will notice that the most energy guzzling ceiling fans rarely use more than 100 Watts.

On average, an adequate fan will use somewhere around 65 to 75 watts.

This number does not reflect the wattage of any integrated light fixture; this is a very important note, because a light fixture can use 2 or 3 times as much electricity as the motor.

In the past, some fan light fixtures consumed upwards of 300 watts, which completely eliminates all gains made by even the most energy efficient fan motor. Usually you can fix this energy oversight by either purchasing a light fixture that uses LED bulbs.

Calculate Fan Size by Room Size

Ceiling fans can be categorized in many different ways — style, colour, lights, mounting type — but when choosing a fan for a space you must consider the actual size of the fan: the diameter width or span of the fan blades.

How to Measure Ceiling Fan Size

Fan blade diameter is generally not measured from the tip of one blade to the tip of an opposing blade because few ceiling fans have an even number of blades.

So, ceiling fan size is measured as though the rotating fan were drawing an imaginary circle. The length from one side of the circle to its opposite side is the ceiling fan blade size.

Simply measure one blade from the tip to the centre of the fixture, then multiply that measurement by 2 to arrive at the fan’s size in inches.

Then choose the largest most powerful fan possible with the greatest blade pitch for your room size to maximize the airflow generated by its rotating blades.

[image from lampsplus.com]

I bought two fans, each with five 52-inch blades — the largest fans that fit into my small space. One is installed in an 80 sq. ft. bedroom and the other is in the 200 sq.ft. living room, and on the lowest setting they move a lot of air while costing very little energy to run. The blade pitch was minimal, but that was fine for my purposes. My ceilings are low and I do not require amazing airflow measurements in those spaces.

If you need specific suggestions for choosing a fan size to fit in your rooms, here’s a quick cheat sheet:

Ceiling Fan Size for Very Small Rooms or Spaces:

20″ to 36″ ceiling fans

For:

  • Nooks,
  • stairwells,
  • laundry rooms,
  • walk-in closets, or
  • small bathrooms.

If using in an outdoor patio or in a tiny bathroom, find a damp- or wet-rated fan designed to withstand frequent exposure to moisture.

Fans Size Small Rooms:

40″ to 48″ ceiling fans

  • For rooms smaller than 9′ x 9′
  • small bedrooms,
  • home offices,
  • dens, and
  • full bathrooms.

Look for a whisper-quiet ceiling fan, especially for in a bedroom.

Fan Size for Standard Rooms:

50″ to 58″ ceiling fans for cooling average rooms

  • 10’x 10′ to 16’x 16′ (100 to 256 sq ft) for example:
  • large bedrooms,
  • living rooms, and
  • large kitchens.

Powerful fans can easily cool rooms of 100-300 sq ft.

Under-sized and under-powered fans often result in a fan that is constantly running at high speeds, which increases energy consumption, delivers a stronger airflow which may be less comfortable, and can limit the life of the fan. Again, consider whisper-quiet fans when selecting fans for bedrooms.

Ceiling Fan Size for Large Rooms:

60″ to 72″ ceiling fans

  • 289 to 400 square feet rooms, like:
  • family rooms,
  • large living rooms,
  • large master bedrooms, and
  • outdoor patios (up to 400 sq. ft.) are best with 60″ to 72″ ceiling fans that have reasonable power and airflow (CFM).
  • again, having a whisper-quiet fan can be very significant in bedrooms.

Fans for Very Large Rooms:

Multiple 50″ to 58″ ceiling fans, or one 65″ (or greater) fan

A nice big, quiet fan works well in this bedroom.
  • For great rooms,
  • open attic space,
  • game rooms,
  • combination rooms,

consider multiple powerful fans with high airflow and blades of 50″ to 58″ for rooms greater than 400 sq. ft.

How To Calculate The Largest Size of Fan To Fit A Room

Choose a ceiling fan appropriately sized for your room. Larger fans are capable of moving more air than smaller models, as long as the blades are pitched sufficiently.

For rooms of 225 square feet, ceiling fans with a diameter between 36 and 44 inches is sufficient, but if you can go bigger and the space needs better cooling, install a larger fan with a powerful motor to rotate nicely pitched blades.

Larger rooms need a fan with a diameter of at least 52 inches or more. In rooms longer than 18 feet, multiple fans should be used for best results. You may add two fans to a slightly smaller area if you desire a certain aesthetic.

How to Space Two Fans Equidistantly in One Room

source: https://www.hansenwholesale.com/ceiling-fans/multiple-ceiling-fan-positioning/

Air Circulation Note

Ceiling hugger-fans (flush mount) provide as much as 40 percent less air movement than standard ceiling fans with a downrod amount.

For greater comfort, remember to focus on the blade sweep (width of the fan, blade tip to blade tip), blade pitch (a greater angle of the blade moves more air but requires a more powerful motor), and the resulting airflow (the higher the CFM, the better the cooling).

How to Choose a Ceiling Fan: Size Guide Considering Blades & Airflow

The short answer to how to choose the right-sized ceiling fan for any room is to keep this guidance in mind:

  • Ceiling fans work best in rooms with ceilings that are at least eight feet high, for safety and pragmatic purposes.
  • Ideally, install your ceiling fan so the blades are placed seven to nine feet higher than the floor and 10 to 12 inches away from the ceiling. In larger spaces increase this buffer zone to 18 inches.

Ceiling Height

When selecting a new or a replacement ceiling fan, measure the ceiling height to determine your fan style and mounting options.

When choosing your fan, you will come across the terms “downrod” and “flush” or “hugger” mount; the optimal fan height from floor to fan blades is approximately 8 feet. Many fans have multiple mounting options; if your ceiling is relatively low, your options are limited to the flush mount style.

As mentioned, your ceiling fan height (from floor to blade) should be at least 8 feet high, in an ideal situation.

Mounting Options

Flush Mount (or hugger): Mounted to the ceiling, this option is ideal for rooms with low ceilings or where a low profile is wanted or required. These ceiling fans are mounted flush to the ceiling, with no extra attachment.

Example of a flush mount or hugger ceiling fan type.

Downrod Mount: This mounting option is best for rooms with high ceilings, of 8 feet and up. Many ceiling fans (other than fans explicitly flush mount) include a downrod. Check the packaging for a downrod and note the size — for extra-tall ceilings, you may need a longer downrod than provided.

Important: If your ceiling fan has a light fixture, reduce the length of the downrod by 12 inches.

source:homedepot.com

See below to help calculate the ideal downrod length. These are a guide, not a rule:

9-ft ceiling6-to-12-inch downrod
10-ft ceiling12-to-18-inch downrod
12-ft ceiling24-to-36-inch downrod
14-ft ceiling36-to-60-inch downrod
16-ft ceiling48-to-84-inch downrod
18-ft ceiling60-inch downrod
20-ft ceiling72-inch downrod

Depending on the height between the floor and your ceiling, you’ll have a different selection of fans to deliberate over. For vaulted ceilings, make sure the tips of your fan’s blades are at least 18 inches away from the walls and ceiling.

The Takeaway
  • For rooms with tall ceilings, you’ll want to choose a fan with a downrod of adequate length, as the image above shows.
  • For optimal air circulation and proper functioning of the fan, the fan blades should be positioned 8 inches or more from the ceiling, and 18 inches away from the surrounding walls.
  • For safety, the bottom of the fan needs to be at least 7 feet above the floor.

Size, or Pitch? What to Consider When Picking Ceiling Fan Blades

All about the right angle: the look of a ceiling fan’s blades are less a feature and more a design preference — the fan’s ability to move air is determined by the pitch of the blades.

What is the Fan Blade Pitch?

Blade pitch is the slope of the fan blade. In other words, it is the angle (in degrees) of a ceiling fan’s blade tilt.

Blade pitch is important because the higher the tilt, the more the motor works to push the air when the fan is rotating. The greater the blade pitch, the more air the fan can move. Thus, the greater the fan’s blade pitch, the greater the fan’s ability to move air (increased CFM).

In order to feel that your fan is moving enough air effectively to cool you down on those muggy summer days, look for a fan that has a blade pitch of 12-15 degrees.

10-11slight pitch
12-13medium pitch
14-15steep pitch (this fan needs a powerful motor)
Slightly pitched blades can work well too, if the fan motor is powerful enough to generate and maintain a nice breeze.

Design Considerations

Many fans these days have reversible blades, so if you feel like changing the finish, you can reverse them — a two-for-one! The number of blades and blade shapes are also constantly changing. Some fans have as many as nine blades, for a helicopter style, and some trendy fans are going for the 3-bladed propeller look. You can’t go wrong with the traditional four or five-blade classic ceiling fan, so choose whichever fan you like. The important choice is the fan motor and blade pitch.

What Size Ceiling Fan for Outdoor Living Space

What about the perfect ceiling fan for an outdoor room? On an open or screened porch, a ceiling fan can provide a refreshing breeze on still summer days. Ensure your fan is rated appropriately for damp or wet locations, and look for one that has weatherproof fan blades, too. Wet-rated fans are suitable for coastal or rainy areas, but damp-rated fans (for bathrooms, for example) shouldn’t come into contact with water.

A Short Word on AC vs. DC Motors

AC (Alternating Current) motors use electricity to produce a rotating magnetic field to spin the rotor. This is the common, affordable motor with which most are familiar. Accordingly, AC-powered fans offer more design and style options on the market. AC Motors are also quiet when installed properly, reliable, and most ceiling fans are equipped with them.

DC (Direct Current) motors convert electrical energy to mechanical energy, and utilize up to 70% less electricity. But are often more expense to purchase upfront. DC motors are light in weight, whisper-quiet to run (great for bedrooms), and boast a longer motor life thanks to efficiency advancements.

Why would anyone want to use ceiling fans to cool themselves when they already have an air conditioner, you might ask. Aside from their efficiency, ceiling fans take up less space making them ideal for cramped spaces, renters, and for use in bedrooms.

Save Money Using a Ceiling Fan With Your Air Conditioner

Growing up in my grandparents’ house in Ontario’s hot and humid summers, they had high ceilings and three ceiling fans in their main living space, with no air conditioning. The ceiling fans and closed curtains made a huge difference to our comfort all summer long. But many people use their ceiling fans in their home until it just gets too hot, then they turn the fan off and crank up their air conditioner.

That’s a mistake.

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Why not optimize and take advantage of what you have? Combining your ceiling fan use with your air conditioner together can save you some serious dollars, especially in Ontario where electricity ain’t cheap.

But to do that, you have to use them properly.

Here’s how.

First, Make Sure Your Fan is Spinning in the Right Direction

The ceiling fan needs to turn in the right direction in the summer months to properly cool you off. Don’t worry about clockwise or counterclockwise necessarily, because some fans might have blades that are angled opposite the standard blades.

Just make sure that the blade is turning with the higher side of the blade leading the way. The fan should be pushing air down. You should be able to feel a breeze when standing directly under your fan. If you do not feel the breeze, turn off the fan reverse the fan’s rotation. Usually you simply flip a switch on the motor that changes the direction of the blades. If you don’t know how to change the direction of your fan, click that link for pointers.

Next Step in Saving Money: Turn Up That Thermostat

When your ceiling fan helps to cool your body, even though the air temperature may not change, you will not feel the need to lower the thermostat, right? Right.

Setting your thermostat at a higher temperature is the KEY because if you only turn on your fan, you’ll actually be using more energy than you were without it (although not much since fans don’t use much energy). Turn up your thermostat up a few degrees — test it 2 degrees at a time to see if anybody in your household complains. Aim for 78 or 80 during the day, and see if you can handle 75 degrees at night. If not, experiment and adjust.

Don’t be afraid to experiment with thermostat settings that normally would be too warm. The breeze created by your fan should keep you comfortable even with the thermostat set at or even above 80 degrees.

“If you use air-conditioning, a ceiling fan will allow you to raise the thermostat setting about 4°F with no reduction in comfort.”

 U.S Department of Energy

If your body is cooled off, you can comfortably set your thermostat at a higher temperature in the hot summers, giving your AC unit a rest, thus saving you energy and money. Using your AC unit less also lessens the wear-and-tear on your machine from everyday use, thus potentially improving the longevity of your unit.

So, ceiling fans save you energy because they help you handle a warmer indoor temperature when you turn your thermostat up. 

And Remember to Turn Off Fans in Unoccupied Rooms

It’s important to note that fans do NOT lower the temperature in your home. They simply make the air feel cooler. This is the same reason windy days feel colder than normal days even if the temperature is the same (wind chill). So leaving fans on in rooms that have no one in them wastes money.

The Money-Saving Part Isn’t Really the Ceiling Fan

As you may have noticed, the ceiling fan itself doesn’t save you the money on air conditioning costs—the savings come from turning up your thermostat in the hot months. (And every degree you can raise your thermostat saves you more money).

But the ceiling fan enables you to remain comfortable while raising the thermostat.

And every degree in temperature that you raise your thermostat in the summer, corresponds to around a 1% change in your electricity bill.

Do Ceiling Fans Help Lower Heating Costs, Too?

If you have an older, pre-90s built home with poor or non-existent duct work, ceiling fans can help distribute heat around your house keeping you more comfortable in the winter.

Do ceiling fans help heating? Yes, they reduce the amount of heat needed by helping you benefit from the warm air already produced by your heating system and can reduce the risk of needing a furnace repair in the dead of winter. Ceiling fans work to evenly distribute air in the room; older homes benefit from this air circulation and by turning your thermostat down a degree or two, you will notice a difference in your heating bill (or the amount of wood burned).

On the lowest setting, your ceiling fan’s blades draw warm air up toward your ceiling, and the rotating motion pushes this air out toward the edges of the room before circulating it back to the ground. With air warmer pooling naturally at the top of a room, this air re-distribution helps the whole space feel warmer by pushing warmth back down to reach your body.

You benefit with more of the warmth produced by your heating system. This helps you feel comfortable even if you set the thermostat back a few degrees.

How Low Can You Go?

I’ve experimented and found that turning the fan on the lowest setting is still too chilly combined with a thermostat set between 60-65 degrees Fahrenheit in the colder months; setting the temperature to a minimum of 67 degrees Fahrenheit with the fan makes the room comfortable for me, and nobody else notices that the heat isn’t cranked.

For me, a ceiling fan only makes sense when I’m in a room that has warm air to recirculate. That means I turn the fan off when the temperature drops below around 67 degrees F, or the fan breeze gives me a chill. That’s just me.

Using a Humidifier and Ceiling Fan

If you use a humidifier in your home (which you should — and aim to keep the indoor relative humidity at around 55 (or at least between 40 and 60 percent) percent to allow the air to hold the right amount of heat without causing mite, mold, or mildew problems), the same advice for ceiling fan direction applies: clockwise spin to warm indirectly, and counterclockwise to push air down to give and wind chill effect.

Or Skip the Ceiling Fan for Ultimate Savings, If…

If your home is relatively new (built since the 90s) and has wall and attic insulation and decent duct work, you might be better off skipping the ceiling fans if you want to save money.

Why? Because people with ceiling fans don’t always remember to turn the thermostat up while using the fans. And that is the whole point — to adjust your furnace or AC thermostat so your units don’t work as hard — if you’re going for energy savings.

If you’re using fans because you like the look of them or whatever, then more power to you.

But if you heard that using a ceiling fan saves energy and money, consider that you will likely save even more money by simply turning your thermostat up a bit and dealing with the summer heat.  A 2002 Utility Ceiling Fan Study conducted by the California Measurement Advisory Council (CALMAC) found that only two percent of people actually do turn up their thermostat when using their ceiling fans. And of those TWO PERCENT, the best possible outcome would be a 15 percent reduction in energy costs.   

15 percent is a decent cumulative, but does that savings pay for the ceiling fan purchase(s) to being with?

Ceiling fans cost at least $100, plus if you plan on living in your home for fewer than 18 years, you won’t recoup the savings ceiling fans might provide in allowing you to turn your thermostat up in the summer and down in the winter, unless your energy costs are going way up.

Remember to buy the right size of ceiling fan — and make sure it has enough power to move enough air to in fact cool you — and you just might come out ahead!

Which Way Should Your Ceiling Fan Spin? Heating and Cooling Strategy

Why do ceiling fans turn both ways? Does it matter if your fan’s blades are rotating around the motor to the left or to the right?

It does indeed!

Your ceiling fan is more than decoration — it is an investment in your home’s energy efficiency and comfort.

But few homeowners (or renters) know how to take advantage of their fans directional benefits, and many people actively work against themselves by leaving their fans on counterproductive settings.

Table of Contents

Ceiling Fan Direction Settings For Cooling

Ceiling fan direction to cool a room: to make the most of your indoor ceiling fan, set the fan to spin counterclockwise on medium or high speed in the summer or on warm spring and autumn days to push air down toward you, to evaporate sweat and thus cool your body. 

Ceiling Fan Direction Settings For Heating

To help circulate warm indoor air on colder days or during winter months, reverse your fan so the blades rotate clockwise on the lowest setting. This movement will pull the warm air up and out against the walls, circulating the warmth without giving you a wind chill effect.

Use Your Ceiling Fan to Save Energy in the Summer

Do ceiling fans cool the air? Technically no, although they do help: in the hot and humid summer months, your body attempts to cool itself by sweating. Sweating itself does little to help cool your body, but the subsequent evaporation of the water from your body is where the magic happens. This is why when you are in high humidity areas, it is difficult to manage your body temperature — the sweat from your body does not evaporate fast enough, and you feel muggy and damp.

By moving air (even warm air) across your body, you assist with this cooling process. Makes sense.

Ceiling fans push air down across your body and create a windchill effect. The breeze evaporates moisture from your skin which makes you feel cooler.

By doing so, your ceiling fan keeps bodies cooler so you are able to stay comfortable and even set your thermostat a few degrees higher, if you have air conditioning in your home.

Using Proper Ceiling Fan Direction When Air Conditioning is on

When the air conditioning is turned on and cold air is blowing up through the vents, have your ceiling fans continue their counterclockwise (left-turning) direction on a medium or high setting. Yes, cool air sinks anyway, but the air being pushed downward by the fan will move around your body faster and quicken the cooling action.

In Which Direction Should a Ceiling Fan Turn in Winter Time?

Whether you use a gas fireplace or wood stove or electric heat or central heating with floor and ceiling vents, the same thinking process applies when switching your ceiling fan to rotate clockwise in the wintertime.

Ceiling fans don’t heat the room, but they do circulate the air. So if you have warm air in your house, it will rise. That warm air is useless to you when it is hanging out along the ceiling. By turning your fan on so it rotates to the right (clockwise) with the blades angled as in the diagram below, your fan recirculates that warm air by pushing it up against the walls and back down to where it needs to go — back down along the walls and out to warm your shivering little body.

Ceiling Fan Direction Diagram

Switch Up or Down?

If your ceiling fan has a reversing switch, at the beginning of each winter and summer season, reverse the fan direction.

  1. Turn the fan off.
  2. Locate the reversing switch. It is on the base of the fan near the fan speed and light switches.
  • Switch up = clockwise = to circulate warm air in winter (when you want warm heated air to circulate indoors)
  • Switch down = counterclockwise = to cool in the summer (with or without air conditioning indoors)

How to Reverse a Ceiling Fan With No Switch on the Motor

Using the Remote

Some models of Hampton Bay fans use a remote control device that adjusts operating times, temperatures, speed and rotation direction. Changing the direction of a remotely controlled Hampton Bay fan is a simple process:

  1. If your fan is powered by a switch at the wall, flip the switch to make sure power is going to the fan. Make sure the blades are not rotating.
  2. Press the “Reverse” button on the remote control of the ceiling fan to change the direction of the airflow. Press the “Reverse” button again to revert to the previous direction of airflow. If your fan does not have a remote control, proceed to the following video:

Another Way to Reverse the Fan if There is No Switch Nor “Reverse” Button on the Remote

Ceiling Fan Direction Cheat-Sheet

Ceiling Fan Direction Diagram

Counterclockwise directly cools, clockwise indirectly warms without a draft.

Ceiling fan direction to cool spaces, attics, lofts above the fan:

Technically, the clockwise direction will pull air upwards, so if you are aiming to cool a loft that sits above a ceiling fan, if the fan is large enough, pulling the air downward (counterclockwise) can move enough stagnant air so that cooler air below can replace it.

But the main cooling action of a ceiling fan is in its ability to blow air across your body. In which case, pulling air upward (which is traditionally the “winter” clockwise setting) might just do the trick.

The correct direction for the blades to turn on a ceiling fan installed at the top of stairs or on a second floor stairwell?

If your goal is to push warm air from upstairs to downstairs, then make sure the fan is turning counterclockwise (summer setting).

If you want to pull cool basement air upwards and the ceiling fan is located at the top of the stairs leading up from the basement, then reversing the fan to its clockwise rotation (winter setting) makes sense.