Question about seemingly high usage from a florescent light

Hello community,
Quick question to run by you all.
I have a standard “office style” florescent light in the laundry room.
This is the only florescent light in the house.
It consistently shows about 140 watts of usage since installing sense about a week ago.
Google-ing is bringing up that this type of fixture usually has a ballast rated around 40-ish watts (unsure of actual model)
Does this seem right?
All other devices in the house are showing very close to what they are rated for on the sense meter, expect this light.
Do you think maybe it’s failing? Do ballasts throw sense off in some kind of way?
I probably will replace this light with an LED type fixture, but not knowing why it is appearing to draw so much power (in my already power hungry house) is baffling to me.
If you guys think it (the light) may be failing, that will motivate me to change it faster, but eventually it will get changed out anyway.
I did pop my head above the ceiling quick and it does not have an “out” so I know no other devices/lights are turning on that I may be unaware of (moved into this house in August)


How many bulbs in the fixture ? Each tube will usually run around 32 to 40W. It looks like you might have 2 banks of 2 tubes in there, assuming it is a typical 2’x4’ drop ceiling fixture.

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Ahhh, I didn’t know it was per tube, I thought it was per ballast.
Correct, 4 tubes total.
Yeah, still going to look at LED solutions, but glad to know it’s most likely not failing at this point.
Thank you for the super fast response.


Get the LED replacement that doesn’t require a ballast. I did it with my garage light and it made a huge difference. Plus it’s instant on.

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It’s correct and due to bulb number. I have 9 in my garage and it was at 280 watts until I changed for direct wire replacement LED. Now they use 129w.

I paid $40 and for 12 bulbs. I just had fri cut the wires to bypass the ballast, very easy to do.
They are also much brighter. Glad I got extra bulbs as one of these “15 year” bulbs went out after a couple months.


@Harrison, Replace it with this:

I replaced all my lights in my basement with these. I have 3 on one switch. Sense found them within a week. I was impressed.

Easy install. Remove bulbs, remove wiring from fixture, remove fixture. As a bonus, new fixture is thinner and lighter than the old one.

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Are you sure LEDs are brighter? What are the lumens on your lamp? EVERYTHING I’ve seen tells me fluorescents are brighter. I have not changed to LEDs because based on the package specs, I would lose 600 lumens per lamp. In my garage I have a two-lamp fixture, and I feel I don’t have enough light. It appears I would lose 1200 lumens by changing.

Compare the following lamps of the same color temperature:

Lumens is a measure of the luminance of a light source in all directions. A high luminousity light source can appear to be dim if none of its light is directed at an observer.

What you want is a measure of illuminance, in Lux or candela. This is a measure of brightness at the observer and you’ll probably never see a spec for it from the manufacturer because its all dependent on how the light is focused which is outside the manufacturer’s control.

So my guess is that the LED has lower luminance but because its light is focused in only one direction, its illuminance is higher… The florescent light output is 360 degrees around the bulb. Not all of it reaches the observer and will be less focused that that from an LED. Hence, it appears dimmer.

Everyone I know who has installed LED bulbs comments on how much brighter they are even though the lumens spec is lower than that for florescent bulbs.


I believe the same thing. My lower lumens LED ceiling can floods illuminate everything below them “better” than the original higher lumens incandescent and later florescent floods. LEDs without diffusers are much more directional.

Thank you for link, I know what I will be doing this upcoming weekend now.
I am ok with loosing a few lumens for the energy saving and sense detection, the room is very small as it is…
(sense has not detected that light since installing sense Jan 11th)

Off Topic: Sense has detected my well pump, microwave, main fridge, main fridge light, mini fridge, water heater, heat pump, bathroom baseboard heater, garage door opener, some burners of the stove and oven, and the upstairs bathroom vanity light. (not to bad for first week, in my opinion)

I’ll post pictures of led light installed and let you know how I feel about the lumens/brightness after install.

I didn’t keep the package to compare lumens but that isn’t as accurate as most believe. Keep in mind the manufacture decides how the testing and measurements are made for their stated lumen output and their isn’t a required industry standard at this time.
I’m comparing what my eyes see and I know I purchase the same color temperature for all my lights.
When I was rewiring the ballast to bypass them, I had fluorescent in some of the fixtures and the new direct wire in others. It was definitely a lot brighter.

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Not ready to make the jump yet, but thanks for everyone’s information! I’m thinking about converting my 2-lamp fixture to 4 direct wired lamps. I would not save electricity, but I should have enough light…

Installed, very happy, thanks for recommendation.
Maybe just slightly dimmer than the other one, but honestly very close to before.
Not even noticeable in this small room.
What is very noticeable is that it is consistently registering as 41 watts on sense.
So I have basically the same light output for 100 watts less.
I also like that the light output is “flat” and completely uniform, unlike the last one where you could clearly see the bulbs.

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@Harrison. Looks good! Your thoughts echo my thoughts exactly. I didn’t notice hardly, if any lumen difference to my eyes. Easy enough to add a second one if you wanted to. The even light is a sure winner in my book. Thanks for posting the photo!

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