How Much Weight Tin Can A Ceiling Fan Agree

Ceiling fans are curious appliances. For about argue, when humans run across them, mutual sense fades and nosotros wonder what manner of fun could be had amongst the rotating blades. I was listening to a podcast the other mean solar day too the presenter, who is an actual in addition to well-known doctor of genetics, was explaining how his family unit plays a game in which you lot toss your underwear onto the blades in addition to meet how far they fly.

So, when people enquire how much weight a ceiling fan can concur, nine times out of ten, it’s because they accept approximately antics upwardly their sleeve. Perhaps I am misjudging you. Maybe you lot are merely wondering if you lot tin can role the ceiling fan to secure more or less bunting or streamers for a political party. Whatever your motivation, though, the facts are the facts, in addition to the facts are presented below.

Ceiling fans are non designed to back up any weight other than their own. The supporting system (downrod, mounting bracket, junction box, too joist) is designed to hold the weight of the fan. An additional few pounds may live safely added just it depends on far likewise many variables to live recommendable.

How Is a Ceiling Fan Supported?

Ceiling fans tin can alone agree as much weight equally their support arrangement can withstand. A typical ceiling fan is supported by a downrod, a mounting bracket, a junction box, in addition to a ceiling joist.

supporting features of a ceiling fan, ceiling fan parts

There are, of class, variations to this basic model. For case, flush-mountain or hugger fan models eliminate the downrod, too a ceiling fan installed between ii joists is connected to both via a couple, which comes between the bracket as well as the joist.

We volition merely wait at the basic back up organization for simplicity’s sake.

Downrods in addition to Brackets: Weight-Bearing Capacity

I take been researching ceiling fans for a spell forthwith, together with inwards the form of my inquiry, I accept never come up across a ceiling fan manual or spec canvass that lists the weight-bearing capacity for a downrod or a bracket.

However, every bit these two parts come up amongst the fan, it is safe to assume that they tin back up the operational weight of the whole fan.

A ceiling fan typically weighs between 8 too fifty lbs, and then yous should await the weight-bearing capacity of its mounting parts to autumn within that range. It is a rather broad reach, which agency that y'all volition accept to await at the possessor’sec manual to encounter the actual weight of your fan.

Junction Boxes: Weight-Bearing Capacity

Junction boxes do non typically come up with the ceiling fan, too they are not specific to fan installation. They are required past code for every electric projection that involves a wiring connectedness. This way that at that place are dissimilar types available.

For a ceiling fan, the junction box performs the dual function of housing the electric wires too supporting the weight of the fan. As a consequence, regular junction boxes, which are designed to support things like calorie-free fixtures, aren’t ever suitable for ceiling fan installation.

Instead, ceiling fans are to be mounted on fan-rated junction boxes. Fan-rated ceiling fan boxes will country the maximum weight or weight range that they tin safely support. Many are rated for 50 lbs only y'all do get close to that are rated for up to 75 lbs.

The junction box used for a ceiling fan must always live rated for weights greater than that of the ceiling fan itself together with this rule is reflected in the manufacturer recommendations.

For example, the Minka-Aire F5240WHF _{^{(amazon link)}} weighs ten.36 lbs simply the manufacturer recommends that the outlet box should back up at to the lowest degree 50 lbs. Another case is the Hunter Dempsy Low Profile Fan _{^{(amazon link)}}, which weighs about 18 lbs only the recommended junction box weight-bearing capacity is seventy lbs.

The argue for this seemingly excessive support is something called dynamic load, which you lot volition call for to sympathise inward guild to accurately in addition to safely determine how much weight your ceiling fan can hold. Before we become to this important concept, withal, nosotros are offset going to await at the final supporting bespeak of the ceiling fan.

Secure Junction Boxes to Joist

In addition to the junction box having to be rated for ceiling fans, they also accept to be attached to the ceiling joists. This makes sense because drywall cannot concur the weight of a ceiling fan, so your ceiling boards would collapse.

Your ceiling joist is office of a construction designed to concur the whole house upwardly, and so this is for certain non what chemists would call the limiting component inwards the example of how much weight a ceiling fan tin concord.

What Is the Dynamic Load?

Now nosotros come to dynamic charge.

Anything alongside a static volume (1.e., all thing) will prepare a dynamic load when lay into motion. This dynamic load will live greater than the static bulk because you lot are increasing the number of forces acting on the object.

A static ceiling fan is being acted on by bulk of the fan as well as gravity. When set into motility, yous add together the forcefulness of velocity. Why is this of import for us to know alongside regards to how much weight a ceiling fan tin can hold?

Quite just, it is of import because the bulk of a fan as indicated by the manufacturer entirely refers to the static bulk.

Rotational dynamic charge is too known as centripetal forcefulness. It is measured inward Newtons together with it is represented inward the next equation:

Here, F_c is the centripetal force, k is the volume, five is the velocity, in addition to r is the radius.

Mathematically, a fan’s dynamic charge is directly proportional to the fan’s volume too velocity, and it is indirectly proportional to the fan’second radius.

If you don’t know what it way for something to be direct proportional, it way that when the static volume as well as/or velocity of the fan increases, and so besides volition the dynamic charge, too if the radius of the fan increases, and so the dynamic charge decreases.

How Added Weight Influences Rotational Forces

If yous never turned the fan on, and so the maximum allowable weight you lot tin hang from the ceiling fan is the departure between the weight of the fan as well as the maximum sum of weight the junction box tin concord.

When yous make plough the fan on, dynamic charge enters the arrangement as well as complicates things. I hope to un-complicate it for you.

As far equally I tin can enjoin, the allowable weight of a fan hanging from a junction box is almost twenty-40% of the weight rating of that box.

allowable weight of a fan hanging from a junction box is about 20-40% of the weight rating of that box

So, for a box rated for l lbs, this means it tin hold a weight of ten-20 lbs. The remainder of the weight-bearing capacity of the box is allocated to bargain with the centripetal force.

If you lot took a 42″ fan weighing 16 lbs, then you would take or so four lbs of weight to “play” alongside.

Before you become attaching your four lbs items to the ceiling fan, all the same, recall that the human relationship between dynamic charge too bulk is non isolated. There are other forces that come up into the equation, namely velocity as well as radius.

Influence of Velocity

Taking our 42″, xvi lbs fan, allow’second farther assume that at that place are ii speed settings. One setting is 200 RPM as well as the other is 400 RPM (average low and high speeds for ceiling fans).

On the depression speed setting, the fan has a dynamic charge of 1,697.6 north.

On the high speed setting, the fan has a dynamic charge of six,784 north. As yous can come across, this is a massive divergence.

Now, add together iv lbs as well as nosotros get dynamic loads of ii,122 due north in addition to 8,480 northward on the low and high speeds, respectively.

Assuming that fan manufacturers calculate the centripetal strength that a fan tin can handle based on the weight of the fan too the highest velocity that the fan tin can reach, then our hypothetical fan tin handle a dynamic load of upwards to vi,784 north.

If yous add iv lbs in addition to position the fan on the lowest setting, you don’t pass this merely every bit before long as yous switch it to the high speed setting y'all do, and the fan becomes unsafe.

The Role of Radius

Finally, allow’sec expect at how radius plays a function. If you increment the radius, you decrease the dynamic charge of the organization.

If y'all tin can detect a 52″ fan of the same weight (sixteen lbs), so at a high speed, the dynamic load (the hypothetical maximum allowable dynamic charge) is v,480 north. This is lower than when the fan was 42″.

Adding iv lbs makes the dynamic load i,714 N for a depression speed setting, as well as half-dozen,850 N for a high speed setting.

So, the higher speed setting with the increased weight however produces a dynamic load greater than our presumed maximum allowable charge. However, the departure is smaller. The deviation is one,696 northward inwards the showtime scenario and 1,370 N in the moment.

To confirm the tendency, I performed the calculation for a 72″, sixteen lbs ceiling fan in addition to obtained a divergence of 989.4 north.

Increasing the size of a fan without increasing its weight volition increase the sum of additional weight yous can add. The charge per unit at which this happens, nevertheless, is likewise slow to live realistic, particularly considering the fact that you are non probable to detect a large enough fan with such a minor mass to make the maths operate.

Where the Additional Weight is Added

One final consideration is where you lot are adding the additional weight.

The weight rating of a junction box is the weight rating of the junction box. It’second not the rating for the fan itself. This agency that, technically, we take no slowly fashion of establishing how much weight a ceiling fan tin concord.

In guild for all that we take learned then far to live applicable, nosotros would take to attach the additional weight inwards the right place.

Let’second become through a hypothetical scenario to exhibit this. Let’sec say y'all want to hang from the ceiling fan (please, don’t).

If you lot were to hold onto the downrod, and so your weight is beingness supported past the whole ceiling fan back up organization. Grab onto a blade, even so, in addition to your weight is exerted on the bracket securing the blade to the torso of the fan, together with it volition bend if not suspension off alone.

Don’t Hang Anything From a Ceiling Fan

With careful calculations, y'all tin can in all probability work out how much weight a ceiling fan tin can concord, in addition to if yous attach this additional weight to the fan correctly, you might not face up whatsoever negative consequences.

However, inward my persuasion, the solely things that should hang from parts of the ceiling fan are other parts of the ceiling fan. What I mean by this is that you tin can hang the fan torso on the bracket and junction box, together with yous tin can hang the calorie-free fixture in addition to blades on the fan torso.

You fifty-fifty need to live careful about replacing or upgrading the ceiling fan blades. If the new ones are heavier that the quondam ones, it can campaign trouble.

Perhaps a fleck of mistletoe to spice upwards your Christmas political party, a duad of lightweight ribbons, etc., these are non going to campaign an result. Anything else should be avoided.