That’s because a fan always has the same basic design in one form or another: fans use angled and slightly curved blades to cut through the air and force it forward or backward depending on the direction of rotation. :confused: Does it really matter whether it sucks or blows? They also keep air circulating within a room, offering a continual effect that makes you more comfortable. My goal is to help you enjoy a fresher home! Then I thought of putting a computer fan on the desk for hot summer days but I couldn't tell from the picture in which direction the fan would rotate. Note: Some older and cheaper Power Supplies come with an 80mm fan at the rear. That’s because DC power can change the operation of the electric motor inside the fan, causing the blades to spin in the opposite direction and force air to the rear. Ceiling fans should hang between seven and nine feet from the floor. (the side with the guard/motor support) Lastly, the fan airflow can be identified by the arrow markings on the fan housing. Great article. look at the fan, if you can see, the support brackets/motor, then it blows that way, if you look and its just the fan blades and the center spins with them, then thats the intake, btw you cooler is backwards, also most fans have a arrow on them showing the direnction that the air goes Airflow through the case is important, so yes, it matters. Being able to tell which way a fan blows isn’t difficult in most cases. Here’s an animated image I’ve put together to help show this. However, direct current (DC) fans are often reversible. You can also look at the curve of the fan’s blades to determine how it’s carving the air, or spin by hand and feel for airflow. You can expect that side of the fan to be the exhaust side. Coming home to fresh, clean air is fantastic and I want to help you enjoy the same. Likewise, if the blade is angled down and the fan turns the opposite direction, the reverse is true. This is a common small fan powered by direct current (DC) and used for many electronics cooling applications. It’s really handy to remember method #1 above. One side it will obviously be blowing and pushing your hand away. The great news is that generally speaking it’s easy to tell fan air direction if you know what to look for. How do I determine in which direction the fan in my NH-D15S should face? Determine where the PSU is intended to fit; this is typically at the bottom of the case in most modern chassis designs. They’re different from other types as they produce a tall, vertical area of air and often oscillate (move side to side) to cool a room. I mounted the fans now, but have no idea whether it is exhaust or intake. Find out how much electricity an air conditioner uses vs a fan here. They don’t work by chilling the air. The other side will be doing the opposite and will suck your hand in. Infographic – Fan facts and airflow basics, How to tell which way a fan blows – 3 basic methods. hide. Tower fans like the popular Lasko Wind Curve at Amazon are an excellent example of this. Here the rear 80mm fan works as an exhaust fan for the PSU. some of the best box fans for white noise you can buy. Radiator Fan direction, Suck or blow, in or out? The way I think of this is to ask the question as to what is the leading edge of the blade as it rotates? For instance, run the fan counterclockwise if an oven heats up your kitchen beyond what’s comfortable, or body heat from a gathering of people makes a room too toasty. Do they make a fan (like the Centrifugal) that blows downward and the intake is from the side, not the top? A fan’s direction is often fixed and largely determined by what it was designed to do: Most common home fans used for cooling like this Lasko 3720 window box fan are designed to blow only one direction: forward. So on a 3 pin connector, do I just switch the places of the left and the right pin? Copyright © Copyright © 2017-2021 AFresherHome.com. No. If you want to heat an area the fan is set behind the radiator (or other heat source) and blows forward through the surface area fins to push the heat outward (nominally, forward). Yes, there are some fanless PSUs available too but they … If you look at the side of the fan you will find a small arrow. Hi Bobby and thanks for dropping by. Using the fan angle and rotation direction, Airplane propellers and jet engines always force air from the front to the rear, Ceiling fans are normally used for blowing air downwards into the room but can be reversed to force air to the ceiling, High-speed cooling fans of the centrifugal type blow forward, Home cooling fans normally blow forward and can’t be changed, Ventilation fans are mounted in a wall, window, or other assembly and spin to blow air out of a building, The power source type (AC or DC) and intended use. Or is it up to the manufacturer to decide? 2. If a fan has its voltage reversed or is designed to rotate in the other direction then yes, the airflow can be reversed. Even tiny PC fans are optimized for aerodynamics and quietness. A fan that blows air out of the case will blow the paper away from case. I just came across your site and appreciate the site also and wanted to ask a question. The direction of the PSU fan is crucial for airflow. An overhead fan can create a relieving breeze or recirculate heat during cooler months—if you know how to change the ceiling fan direction. Heat sink and CPU fan. I thought laptops had that type fan. The side of the fan that has the support structure to hold the motor and wires going to it is the output side. The Rear or Exhaust side (the side that the air comes out of) of our fans will always be the side that houses the fan motor. If you’re lucky enough to find that on one, it makes it even easier to tell! Or, you could watch the fan as your computer is powering off (the fan accelerates too fast due to electricity as it's starting up which makes it impossible to tell unless you're Ted Williams, but when it's slowing down, it's just friction and some magnets). Be sure you’re using fans to improve your quality of life (and save money) as much as possible! You will also be able to identify the Exhaust side as you will see power wires entering the fan motor. High heat build up, high head pressures, inefficient is an understatement. How can I change a fan from suck to blow? Fans create a cooling effect by the principle known as forced convection. The angle of the fan blades. How do most people have it? In this video, I explain how to setup your cooling fans to create neutral movement air flow. I have 5 enormous fans constantly blowing away on my unit. Try to keep the air flow in your case going in one general direction, with more fans blowing in that blowing out. Depending on the time of year, you'll want to change the direction of your ceiling fan so that it blows cool air around the room on a hot day, or distributes warm air on a cool day. alot of times it doesnt matter which way the fan goes, but just put it to blow air towards the heatsink if you're not sure. Of course, if for some reason the fan rotates in the opposite direction (unbeknownst to me) the air would be blown the other way. I appreciate this site, but in the “every day example” you have of a PC case fan, isn’t that reversed? As I'm sure any rockstar could tell you - the bigger the fan, the better the blow. how much electricity an air conditioner uses vs a fan here. Fans are everywhere it seems! I apologize for some of the rude comments. Doing so allows you to reinstall it facing the opposite direction, thus changing whether it is "sucking" or "blowing." Which direction is the evaporator fan supposed to spin? But....I have rotated the fans now roughly 20 times, but nowhere does it show arrows indicating the airflow. So you mount the fan in the direction you want the air to go. It is an Akasa fan. You will also be able to identify the Exhaust side as you will see power wires entering the fan motor. Air should travel in clear path through the case. Do not mount exhaust fans on the bottom of the case; since hot air rises, a bottom-firing exhaust fan will be working against physics by expelling slightly cooler air instead of warmer air. Want to know how much energy a fan can save? If the fan is attempting to blow into a restriced area (like into a PC heatsink with little clearance) the air can't be thrown outward and away efficiently and instead creates pressure waves and the fan ends up pushing those pressure waves around in a circle in the cavity and moving much less air in total. Since you only supply power, there is a controller in the fan that senses rotor position and commutates the motor accordingly. 1. Here are some great fan facts to know. Centrifugal fans normally only blow in the direction of the outlet as shown, while axial fans may be reversible in some cases. When looking at the fan so that the circular sticker with the Noctua logo is facing you, the direction of airflow is towards you and the sense of rotation is clockwise: . These two characteristics of a fan are probably the easiest and most common way to tell which way it blows. When looking at the fan so that the circular sticker with the Noctua logo is facing you, the direction of airflow is towards you and the sense of rotation is clockwise: . A fan that blows air out of the case will blow the paper away from case. Fans are also very helpful in some cases for blocking outside noises that cause us stress and interrupt sleep, studying, or working. A heat sink that is both active and passive blows air through the finned radiator to help the heat escape faster.. Case fans. Once you’ve got the basics down it’s not hard at all! (the side with the guard/motor support) They work off of the principle known as forced convection. Try checking that. it does matter. both directions. To determine which is the correct orientation for the fan, observe the location of the manufacturer’s sticker on said fan – that’s the direction into which the air is blowing. I recently got a Cryo LX and it blows air onto the laptop, I want to try to mod it to have the fans spin in opposite direction. You want both fans on the radiator going the same direction. But do you know how to tell which way a fan blows? You can see the PSU airflow in the diagram given below. It also depends strongly on the fan’s intended use as well. Although your comment was rude and misplaced I’d like to respond in order to clear up your misconceptions. Fan airflow, as I stated in the article, always depends on the particular fan and is based on 2 things: 1. Keep the fan direction in mind when you’re looking to cool down or warm up a room. Grab a small piece of paper and lay it across the fan when PC is on. The direction of air movement for a fitted fan can easily be confirmed with a slither of paper. The unobstructed side, where you can see the whole fan blade and logo in the center, is the intake side. The image above is a great example of a common fan you might run across. Front fans should be sucking cool air in (arrow towards MOBO), rear fans are obviously exhaust (blowing out, arrow facing the back of case), and side panel fans are dependent upon location. Standing alone, the blow side of a fan does produce a more concentrated, faster moving, and more turbulent "river" of air compared to the intake side where air is drawn almost equally from all directions. It’s best to run the fan on a low speed so that it doesn’t create too much of a cooling breeze. However the NH-D15S mounts the fan in the middle. In arrow located on the side of the fan indicates the direction of air flow. It is an Akasa fan. Neutral pressure – Air pressure in the case is equal to air pressure outside of the case. You’ll need to rotate the fan 180° to change the air direction. However, I am unsure as to what the air flow direction should be. The fan at the bottom of most laptops blow air out, so wouldn't a cooler that blows air onto the laptop work against the laptop fans? Lastly, the fan airflow can be identified by the arrow markings on the fan housing. Perhaps you're in the middle of renovations and need to change the flow of air or the motor to the fan broke and the replacement arrived rotating in the wrong direction. The direction a fan blows air is always determined by (A) the shape of the blades (sometimes called propellers) and (B) the direction they turn. Firstly, the wind normally blows only in one direction IF you’ve noticed. Determine where the PSU is intended to fit; this is typically at the bottom of the case in most modern chassis designs. Reversing the direction of rotation will be difficult. (can't test as waiting for motherboard). If a blade is angled down and the fan turns in the same direction as the blade angle, it will blow forward. The Rear or Exhaust side (the side that the air comes out of) of our fans will always be the side that houses the fan motor. It is very … To figure out whether your PSU fan needs to point up or down, start by looking over your PC case. I'm debating flipping the exhaust or CPU fan, but like I said, I cannot tell which direction it's spinning. it is also advisable to place them on different ends. This morning i stripped the PC to clean out all the dust. How to determine the airflow direction of your case fans. The example shown most certainly is correct. It’s a great and cost-effective way to help you focus, relax, or sleep better. Though you might not expect to need to change a vent fan's direction, this could become a necessity. When looking at our fans, the Front or Intake side of the fan will always be the side that has the Cooler Master Logo in the center of the blades. Even tiny PC fans are optimized for aerodynamics and quietness. Bi-directional fans A “bi-directional fan” has straight blades, perpendicular to the shaft, which may or may not extend to the boss (inside section of the fan that holds the fan on the shaft). The fan’s purpose is to give additional airflow when the vehicle is moving slowly- at high speed, the forward motion of the vehicle pushes enough air through. Centrifugal fans can only blow air radially outwards. report. In simple terms, a computer case can either have: Positive pressure – The case fans push more air into the case than then pull out, so there is more air pressure inside of the case. Fans are typically not very expensive but can be very cost-effective in many applications. Of course, be careful not to allow your fingers to snag in the fan … 2 Observe the direction the fan blades are turning. Air will blow in the other direction (towards the back). I see air filters all that time that have been installed backwards. Posted by 2 years ago. This morning i stripped the PC to clean out all the dust. Have a good day and thanks for dropping by. Would it pull the air from the back or from the front? But did you know? Here’s a cool (no pun intended!) Spinning this way the fan then pushes the air ahead of it. you can have the front end blow cool air in, while the back fans blow hot air out. Conversely, run a fan clockwise to amplify the heat from a fireplace or any other heat source in a room. Fans generally only come in a few basic designs, most of which are axial or centrifugal types. Please use our contact form for any further queries. Left: This fan is the most common type, as it can be mounted backward if you need to reverse airflow. With the simple flip of a switch or tug of a chain, you can start saving costs on your heating and air conditioning bills. Long story but i had to take it off and put it back on and don't know if i hooked the leads back up correctly. 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