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Waste heat from track lighting

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  • Waste heat from track lighting

    In a family restaurant that I eat at about once a week, they have a back room that's about 20 x 50 with a 10 foot ceiling height. Along one of the 50 foot walls are large windows. During the daytime there is loads of sunlight coming in, but the owners insist that the track lighting must be on at all times they are open. There are 4 tracks and each has 6 lamp heads with a 50 Watt halogen lamp (bulb) in each of them. This would mean a total of 1200 Watts of power is used for them. In the summer and on a busy day or early evening that room is uncomfortable warm. The AC unit runs non-stop but just can't remove all the heat. Sure there's lots of heat from the windows and from customers, but I want to get some good numbers on the amount of heat that the track lights add. My reason is that I would just love to have those nasty eye blasters turned off and left off other than after it gets dark in there. Once when I was one of very few customers, I was able to talk the head waitress (She knows the owners very well and NO way would they dream of firing her) to try turning off the power to the track lights. After about 20 minutes we both noticed the room was cooler and I heard the AC cycle off for a few minutes. Does anyone know a good way I can figure the BTU of heat coming off the track lights? I do know most of the electrical energy is waste heat and under 20% is useful light, but I would like some real numbers. Thanks

  • #2
    Re: Waste heat from track lighting

    I had actually looked into this some time ago but for the life of me can't find some really great links with this info I had found. Basically you are correct. Halogen lamps are basically incandescent bulbs which means about 90% of their energy consumption is turned into heat. When it comes to the amount of heat generated 50 watts is 50 watts. The percieved heat generated from halogen bulbs comes from the fact that the light is focused giving the sense they run much hotter than a traditional incandescent bulb. Their filament needs to be much shorter and thicker in order to generate the heat necessary for the halogen gas to have its effect on the filament while drawing the same power or not burn out. Basically all the heat needs to be concentrated in a very small space about the size of a peanut instead of a full bulb. They run extremely hot but in a much smaller space by comparison. That said even if those were conventional incandescent lamps, they would probably still generate about the same amount of heat, which for that many lamps is quite a lot. What I'm guessing might be making those halogens really unpleasant is that are effectively focusing all that heat directly down onto the customers in that restaurant. I for one make sure to reflect all the halogens at home against walls or the ceiling and not directly anywhere people will be. I also dim them down some or use smaller bulbs to make them more tolerable.

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    • #3
      Re: Waste heat from track lighting

      So true about aiming them correctly. For what this is worth in resistive electric heating 1000 Watts would produce 3413 BTU/hour of heat. In this case if we figured a 1200 Watt heating element that would give us 4095BTU/hour of heat. This is a good bit of heat that their air conditioning system has to deal with in that room. If they were off during the daytime when there's loads of sunlight coming into the room that would help them save some on their electric bill and more important there would be less waste heat in that room to deal with.

      I think I'm going to just beg the owners to leave them off during the day during the summer and find out if anyone actually asks that they be turned on. My bet is none of the customers or staff will miss them.

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      • #4
        Re: Waste heat from track lighting

        Are these standard MR-16 bulbs?
        If so, I've seen replacement LED bulbs that are supposed to be as bright as 35W halogens...

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        • #5
          Re: Waste heat from track lighting

          Newman

          These are some "A$$-O-Terrik" reflector with a bi-pin socket and little super blaster pee shooter halogen bulbs. Their system runs on 24 Volts AC. I keep telling to just get rid of them and replace with something more sane but they won't because to them it's all about MAKKA THE MONEY and not spending a cent on upgrading the place. I don't eat there anymore. ***** them greedy fools.
          Last edited by Woussko; 08-05-2007, 08:26 PM.

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          • #6
            Re: Waste heat from track lighting

            Wo, they do make LED replacement bulbs for those fixtures. I've seen them, I know the fixtures you're talking about, they do produce a lot of heat. I have 13 of those fixtures in my office. They are small furnaces. I've been considering swapping the bulbs for the LED's.

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            • #7
              Re: Waste heat from track lighting

              Thom

              I like the LEDs myself. The problem is that the restaurant owner's won't spend a cent on fixing things. What they don't think about is that the waste heat makes their AC have to work harder. Oh well....

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              • #8
                Re: Waste heat from track lighting

                thats true they don't see what it cost to run the ac that long but they see the $ amount it would cost to change it . little that they know if they change the lights and get a removable window film he would be saving $$$$$$$$
                Charlie

                My seek the peek fundraiser page
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                new work pictures 12/09
                http://public.fotki.com/hvachawk/

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                • #9
                  Re: Waste heat from track lighting

                  H H

                  To make this even worse they run the track lights when totally not needed. They are in a room with lots of windows and the sun lights up the place very well. The only times they need them on are early mornings and at night. Master (owner) demands they stay on full at all times when the place is open and NO one but Master dare change it. I think that Master is totally LOCO.

                  I did talk to one of the managers I know. There are 24 heads and each of the bi-pin halogen bulbs is rated at 50 Watts. That's 1200 Watts that's mostly heat. If I remember a resistance heater of 1000 Watts puts out 3412 BTU/Hr. of heat.

                  It's their palce and I don't go there much. My real point is that I hate track lighting alltogether for general room lighting.
                  Last edited by Woussko; 09-03-2007, 10:33 PM.

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                  • #10
                    Re: Waste heat from track lighting

                    about 12 years ago I was doing a job for a guy who had expensive tropical fish. A LOT of Fish. A lot of hot florescent lighting. Hot ballasts at least.

                    2 @ 240gal tanks each with 6@ 4' single bulb fixtures
                    9 @ 120gal tanks each with 4 @ 4' single bulb fixtures
                    12 @ 70 gal tanks each with 2 @ 4' single bulb fixtures
                    8 @ 50 gal tanks each with 2 @ 4' single bulb fixtures

                    ...and the water in the tanks was to hot. He wanted me to re-wire the place so he could add chillers to each tank. I did some load calcs on the fixtures, bought one high efficiency ballast and one high efficiency bulb and amp'd them. I did temp tests on the fixtures to show the difference in heat output.

                    I made him a proposal. I charged him the cost of the high efficiency ballast and bulb plus $60 labor each to swap on 88 fixtures. The energy savings would pay for the cost of the swap in 12 months and he didn't need to pay to rewire the place, buy chillers, and pay for the power of the chillers. My son (a college student) did all the work in one day ($5,280. for a days labor).

                    The point is how you present it. You can give him some real numbers. You can multiply the current power consumption X the number of fixtures, subtract the led power consumption X the number of fixtures then calculate the $ savings in electricity. I'm sure you could find the heat output of those halogen bulbs, do a rough calculation of the cost of removing that heat with hvac per month times a 6 month cooling season, add this to the electricity savings from the led's and you will have a real number to work with. You can show him how much the additional cost of the led's will save him. Then you have hard #'s without the inclusion of fuzzy things like comfort and the number of customers he might be losing.

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                    • #11
                      Re: Waste heat from track lighting

                      Thom

                      True and good work with the upgrade work.

                      I did a "for fun" thing where I made a $20 bet with the general manager (Owners were not there at the time). I got him to shut off the track lights from when I was seated until I left. The bet was that the servers and customers would all love it. If not, they got the $20 bill, but if the servers and manager could really tell the difference in just comfort and that the AC didn't have to really work so hard then I would take it back and have a nice free meal.

                      I won that bet big time.

                      By the way they (darn track lights) are in the second dining room which has always been the non smoking area. Anymore laws ban smoking in about all buildings anymore here. The main dining room and kitchen have better lighting but I bet you could save them good money and add to comfort easy. I did find that the place may get sold at the end of the year. Time will tell.

                      This was on a hot and muggy afternoon when the place was slow. With sunlight very few people even noticed the track lights were off.

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