Good afternoon:
When we put fans in @8 years ago, we went with 52" sweep (diameter) fans in the bedrooms, but for whatever reason, we opted for the smaller 44" sweep fan in the TV room. Since day one it has bugged me that the 44" fan looks too small for the room, and it's a very expensive fan to pull down & replace. I see that the company sells the replacement blades for $40/set of three, and I figured swapping in a set of the larger blades would be the perfect solution.
I sent an email to the company to make sure there would be no problem, and they responded that while the larger blades will fit physically and both the 44" and the 52" fans appear to be identical, they actually have two different motors, and thus the company doesn't recommend it as the smaller fan may burn out "over time" if it is run in conjunction with the larger blades. So much for that idea...or is the company merely trying to sell me a new fan?
When I checked the company's website, it lists specs for my smaller fan motor of 10 watts and 0.19 amps at low speed, and 43 watts and 0.40 amps at high speed. The corresponding specs for the larger fan motor are 12 watts/0.23 amps and 63 watts/0.52 amps.
As we never run these fans on high speed anyway, do you think there will actually be an appreciable difference running the 52" sweep blades with the motor intended for 44" sweep blades at low speed? Thanks for weighing in.
Caveat-- I'm not an electrician but married (happily) 30 years.
Most electrical motors are over-engineered more than 20%. Can't say for sure an exact number, but unless it is the cheapest garbage from the lowest discount rack from China, the motor will likely handle the extra load easily. Fans use very little amperage (current) and as long as the bearings are at least decent quality, it should last.
Having used tools and motors my whole career, I've had a fair share of motor failure...when an electrical motor gets overloaded, yes, heat builds up. But usually it is not the motor/wiring that fails. That can handle heating up. There are rarely sparks. It is normally the bearings within that fail from the increased heat buildup. They heat up, expand, and extra friction causes more heat and it is an exponential buildup. And even if there is a spark, there should be nothing within a properly wired electrical box that can cause ignition.
You will have a bit more weight with the longer, but also more centripetal velocity at the tip of the blades. You may notice more wobble to the fan when 'on'. Double check all of your connections, bolts, hardware for tightness. Obviously if there is any noise; scraping, whining, etc. shut down immediately.
Good luck.
If you only kept the fan at slow speed with the bigger blades it would probably be ok. But if someone mindlessly increases the speed, then that could cause a problem.
In the end, is spending an additional $150/$175 for a newer bigger fan worth even the small risk of fire?
If in fact you won’t ever run the fan at high speed, the difference in motor load of 0.04 amps at low speed is negligible.
However, since these fans run at low speed they do not use precision bearings. I’ve had one apart and the bearings are the weak link. It’s likely that the weight of the blades impose the larger stress (straight down) on the main bearing situated near the bottom of the fan housing.
So you could eventually burn up the bearing, and you will likely know it (noise) before there is any chance of fire. But then again, at low speed, maybe not.
Since the fan is 8 years old it doesn’t owe you a lot - had a good life. Plus $40 invested in the blades won’t break the bank.
I would do this exploratory exercise: after running the fan as it is now for a while, shut it down and feel around the housing for heat. Get a sense for how much, if any. After installing the bigger blades, do the same thing. If you notice a considerable more heat, you will have an idea what the life of this experiment may be. Start saving for the new fan.
Is it still there?
Just install the larger blades, turn it on the low speed and make sure it is spinning evenly. I would be more concerned with the potential shaking of the unit and causing stress at the connection point between the fan and the ceiling box and less about the bearings.
If it pins smoothly, then just enjoy the new fan blades until the unit stops working one day.
** side note, the fan should not be expensive to replace from a labor perspective because you can do that yourself.
So I'd recommend skipping the 4 bucks and a year of loud overstressed bearings and go right for the new fan.
If the fan is in the ground anyway, might as well just hang a new one.
Is it still there?
OP here. Thanks for all the responses. When we bought these fans @8 years ago, they were $250; the price for the identical fan is now $340. I have no recollection as to what I was thinking when I went with smaller blades in the TV room, as the price for the 44" and the 52" has always been the same. Maybe I will wait until it no longer works before I spring for a new, larger one. First-world problems.
There were actually a few Gruning's restaurants, but they are long gone now. Anyone over 40 who grew up in Essex County would likely remember Gruning's.