Engineering Analysis

Engineering analysis has shown that a typical thermoplastic ceiling box can support a greater load without undue strain, simply by the inclusion of our product.  The ceiling box manufacturers rate their products at a standard 35 or 50 lb. static load, though when a ceiling fan is installed this load becomes dynamic and stresses the nailing flange.  Consequently all ceiling fan manufacturers direct their customers to reinforce the ceiling box or install boxes rated for these loads.  This requires that the ceiling box be reinforced by the addition of structural members around or on top of them, or be replaced with special box's that are made to carry this dynamic load safely. 

Our products allows the existing ceiling box to be reinforced with minimal effort in about two minutes with hand or power tools.  In most cases all that is needed is a screwdriver.  Several Screen Captures of Finite Element Analysis (FEA) is shown below and illustrates the fact that the ceiling box is able to withstand a greater load after the inclusion of our device.  Both screen captures were done with at least a 200 lb load being placed on each screw mounting boss of the ceiling box, even with this load it had a factor of safety of approximately 2 times.   All of the analysis was done with the materials yield stress value which varies with the individual components and Algor FEMPRO Software.

All of the analysis shown here used a mesh convergence study to refine the appropriate mesh for the materials and applied forces.  We have not looked at tensile force at break, which would yield greater safety factors than we show in these illustrations, by staying with yield forces we allow a safety margin to our designs that will exceed your expectations for safety & reliability.  Needless to say these products are capable of holding the ceiling box rigidly in place today, tomorrow and for years to come.  Of course we do not recommend that 200 to 300 lbs. ever be placed on a ceiling box at any time, the analysis only shows what is possible when our device is used and installed properly, as shown in the following photos.

Both of these screen captures show the stress on the components, the stress is concentrated in areas that are not considered critical and are only approximately 1/2 and in most cases much less of the allowable yield stress.  Actual testing of our products has verified these findings and is presented on the Intertek page.

No matter which of our products you choose they all have the ability to reinforce the ceiling box and safely carry the load that is placed by your ceiling fan or appliance.  Our product is, inexpensive, small and in most cases can be supplied with ceiling fans or heavy lighting fixture at minimal cost.  We are also selling our products directly to contractors, builders and homeowners, just follow the link above.