Lights Intensity Levels - Page 1
Forum section: electronics / beginners

author: Larsson55
author_rank: Regular Contributor
timestamp: June 18, 2021, 04:49:18 pm
content: Installed a brand new Broan Allure QS1 series range hood in my kitchen, all went fine and we are happy with it. The instructions calls for two PAR20 50W max Halogen bulbs and the unit has a 3 position rocker switch to control the intensity (Low, OFF, High). It also has a second similar switch for the fan speed (Low, OFF, High)Since PAR20 50W bulbs were also available in dimmable LED I decided to install them instead of the Halogen because the LED’s remain cool to the touch. However the rocker switch has no effect on the lights intensity, having the switch in the Low or high position the light intensity remains the same.Is it because I do need to install Halogen bulbs?Perhaps if I install non dimmable LED’s?Thank you

author: Benta
author_rank: Super Contributor
timestamp: June 18, 2021, 05:07:04 pm
content: It's likely that the rocker switch connects the lamp in series/parallel. This works fine with incandescent bulbs, but not with LEDs.Another possibily is that a rectifier/diode is switched in at 50% for half-wave operation.You'll need to look closer at the switch itself.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 18, 2021, 07:21:31 pm
content: Quote from: Benta on June 18, 2021, 05:07:04 pmThank you for your time,The instructions also say to use a R16 40W max. Incandescent bulbs besides the Halogen.Electrically what is the difference between the Halogen and LED bulbs?Kind of difficult to look at the switch now that the hood is installed. I’m thinking perhaps its easier to just get 2 Incandescent or Halogen bulbs and give it a try.

author: TimFox
author_rank: Super Contributor
timestamp: June 18, 2021, 09:40:13 pm
content: Halogen is a specific type of incandescent bulb, which has a bit higher efficiency than the traditional affordable incandescent bulbs that are no longer politically correct.Electrically, incandescent bulbs are just a resistor, a very simple circuit, and work equally well on AC or DC (at the same rms voltage). Lowering the rms voltage decreases the output and shifts the color towards redder.A LED bulb assembly is very different, and includes a built-in solid-state circuit to drive the actual light-emitting diodes.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 18, 2021, 10:23:13 pm
content: Quote from: TimFox on June 18, 2021, 09:40:13 pmThank you for the education, that's what I was looking for. Just to experiment, I installed 2 regular incandescent bulbs in the hood and it works, flipping the switch I now have 2 intensity light levels. So I will go to the store and get 2 PAR20 Halogen bulbs since they are, as you say, of higher efficiency.

author: Siwastaja
author_rank: Super Contributor
timestamp: June 19, 2021, 03:22:47 pm
content: Note that efficiency difference between classic and halogen incandescent bulbs, for the same voltage, is negligible, maybe 20-30%. If you need any real power savings or need the bulb to run cooler, the only option is to use significantly higher efficiency types, choices being CFL (4-5 times more efficient) or LED (8-10 times more efficient).

author: TimFox
author_rank: Super Contributor
timestamp: June 19, 2021, 03:44:57 pm
content: In a range hood application, what is the required temperature rating for the light?

author: Benta
author_rank: Super Contributor
timestamp: June 19, 2021, 04:25:08 pm
content: What's the rationale behind saving power and reducing heat on lights above a cooking range burning 10+ kW? Sometimes I just shake my head.

author: TimFox
author_rank: Super Contributor
timestamp: June 19, 2021, 04:57:24 pm
content: PAR20 bulbs have a parabolic reflector. Is that the correct geometry for your hood?

author: Larsson55
author_rank: Regular Contributor
timestamp: June 19, 2021, 06:48:34 pm
content: I thought I had put this subject to bed but with the new questions here I decided to further educate myself in bulbs and I found this interesting articlehttps://www.superbrightleds.com/blog/led-vs-incandescent-vs-halogen/707/PAR20 bulbs are recommended by the manufacturer of my hood and so the geometry of the hood is designed for this type of bulbs.As far as I know, there is no required temperature rating for the light in a range hood.In my previous post I mentioned that I will go for Halogen bulbs but reading on the above link I think it will be much better to keep the PAR20 LED bulbs I have because the Halogen bulbs are as hot to the touch as the Incandescent bulbs (perhaps even more). Of course I will lose the 2 levels of light intensity with the LED bulbs but safety is more important to me than convenience.

author: RJSV
author_rank: Super Contributor
timestamp: June 20, 2021, 02:06:12 am
content: Sounds, maybe, obvious, but you could always install an extra and dimmable LED wall light nearby. Check your local hardware store for units that operate from remote control. You will gain a bunch of options, such as timer control, shuts off after 4 hours.My favorite new LED unit will also take up as a 24 hour. timer and turn on same time each day

author: james_s
author_rank: Super Contributor
timestamp: June 20, 2021, 05:52:00 am
content: Quote from: Benta on June 19, 2021, 04:25:08 pmWell personally I use the hood light daily for all manner of things that don't involve cooking. I tend to leave it on in the evening to provide some light in the kitchen so I can walk in there to grab something without turning on the overhead light, or if I get up at night to grab a glass of water or something I'll turn on the hood light. I've known a lot of people who would leave that light on a lot as a sort of nightlight.Additionally my range is gas, so there is not really any relation between it and electric use and besides, every watt counts. It makes no difference if a light is in my cooker hood or in my bedroom lamp, a watt is a watt and it all adds up.

author: Siwastaja
author_rank: Super Contributor
timestamp: June 20, 2021, 07:32:08 am
content: Quote from: Benta on June 19, 2021, 04:25:08 pmDon't shake too much,think.The cooking range will not burn 10+ kW continuously, if it did you couldn't live in the same house. This is just peak power. Average power during cooking can be very low for example during simmering or letting the food cool for serving on the stove.I can see many cases where the lights above are turned on for significantly longer; maybe even when you are not cooking to give some general lighting in the kitchen near the stove.So really the rationale to choose those bulbs should be defined by the duty cycle of these bulbs; if theyreallyare only on during 10kW cooking, that's a good reason to ignore their consumption, but not because of the 10kW stove, but because of the short time they are on. Whether there is a stove nearby is irrelevant, high energy comsumption somewhere does not magically nullify savings elsewhere regardless of whether the distance is half a meter or 1000 kilometers.