Downlighting

Discussion in 'Landscape Lighting' started by Alan B, Mar 22, 2010.

  1. Alan B

    Alan B Sponsor
    Posts: 406

    What lamp wattage and beam spread do you prefer for downlighting?

    Assume that the fixture is mounted 25'+.

    If there are variables such as I prefer X wattage and Y degrees for a natural moonlighting look, but A wattage and B degrees if the purpose is to illuminate and area for safety/security. Or if the purpose is to illuminate the tree the fixture is mounted in I use this, but if the purpose is to illuminate a larger area on the ground I use this ...please include that info.

    Thanks!

    Alan
     
  2. emby

    emby LawnSite Senior Member
    from Ontario
    Posts: 380

    Alan,
    I would prefer to use a mixture of 20-35 watt 60 degree lamps to illuminate a larger area on the ground. If you are illuminating a path then maybe up the lamp wattage to a 35.
    If I were to design it so that the fixture is on an outer branch pointing towards and illuminating the lower tree trunk I would use a 20 watt 24-36degree spread.
    This all depends on ambient light as well. If there is lots then 35 watters for sure. If there is no ambient light then all 20 watters except on the paths for safety.

    My 2 cents.

    Ken
     
  3. Alan B

    Alan B Sponsor
    Posts: 406

    Ken,

    Thanks for feedback.

    I was recommending 35w 36 degree as the bread an butter for most applications (I would like to suggest a 60 degree but felt the long shroud of most downlights would prevent the spread and eat up much of the lumens). I wanted to make sure I was giving good advice and that my own experience was correct.

    I have never used a 50w, but didn't know if others did. Also didn't know if most used the 36 degree (due to glare guard) or if they used 60 degree.

    Thanks for the input and look forward to some more perspectives.

    Sincerely,

    Alan
     
  4. RLDesign

    RLDesign LawnSite Member
    Posts: 145

    Hello,

    I have design with anything from 20-50 W, and a variety of beam and lenses. The 50 W has only come into play when I am trying to provide a zone of light for entertaining, and I usually am at an elevation of 30ft or higher. I overlap the circles of light and sometimes throw the frosted/spread lense in the mix to reduce the output and soften the edges. I almost always have those on a dimmer to allow for the correct adjustment to fit the mood. In tree downlights, mostly I have been installing 20-35W.

    I hope this helps.

    Tanek
    Reynolds Lighting
     
  5. Alan B

    Alan B Sponsor
    Posts: 406

    Tanek,

    Thanks for the info.

    Cheers,

    Alan
     
  6. The Lighting Geek

    The Lighting Geek LawnSite Senior Member
    Posts: 875

    Most of the time I use 20watt BAB 38 degree, sometimes a 60 degree. If I am using a 35watt it is to compensate for a fixture mounted higher in the tree so the intensity remains even on the ground. I generally use a frosted lens as well.
     
  7. Lite4

    Lite4 LawnSite Gold Member
    Posts: 3,109

    Generally from 25' or higher I will use a 35 watt FMW, and lower will use a 20 watt BAB. Just depends on what is on the ground that I am highlighting and ambient light levels. I always knock out the front glass on the fixture (if it has any) and silicone in a honeycomb louver to allow any moisture to pass out of the fixture freely. .02
     
  8. Alan B

    Alan B Sponsor
    Posts: 406

    Tim,

    Great tip about the knocking out lens and adding honeycomb louver.

    We are re-designing the Top Dog fixture for downlight specific applications-- possibly we'll use your advice and make the fixtures with no lens and a honeycomb louver instead. When i think about it .. it's a great idea. I don't see why the lens is needed when it will be aimed down, it will keep all condensation,moisture out and possibly help LED retrofits dissipate heat by not keeping the heat trapped inside a sealed fixture.

    We already silicon seal where the wires leave the fixture but it's still possible for water to seep thru the knuckle and into the fixture over time. Accordingly we were going to also silicon seal the inside of the body where the lead wires enter the body-- but I like Tim's idea better--guarantees no water inside the fixture, plus adds the benefit of louvers.

    Anyone see an issue buying a downlight specific fixture this way --no lens and instead have open louvers? What are your thoughts?

    Tim, thank you for the advice.:clapping:

    Sincerely,

    Alan
     
  9. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Posts: 4,102

    I will go out on a limb here (pun intended) and suggest that I have more tree mounted downlights installed than any other contractor who participates on this forum.

    I have tried so many fixtures for this application it would make your head spin. For the most part they ALL have failed for one reason or another. The CAST Treelight CCTL1C is the best product I have found yet.

    Alan, I would strongly recommend you do not remove the lens from your planned tree light. Around these parts we cannot use an open fixture as we get all sorts of bugs, esp. catapillars, moths, and other cocoon type insects that love to establish themselves in the fixture / shroud if they can. Also, if someone wants to use LED MR16 lamps in the fixtures they really need to be kept as dry as possible. An open fixture will allow rain / snow that is whipped up by the wind to contact the lamps. (this will also shorten the life of Halogens)

    As for lamps, I have only used 35W FMW on a couple of occasions when the ambient light dictated the need for a brighter effect. 20W BAB and 3000K45 Deg LED MR16s are my lamp of choice for over 95% of my installed fixtures.

    Remember guys... "the higher the light the closer to God" I try to stay above 30 feet always.

    If you would like to pick my brain on your new fixture, give me a call when I get back to my office.
     
  10. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933


    All of our down lights are buiilt that way for that reason. Heavy snow drifts can blow snow up the shroud but the lamp tends to melt it away. We rarely see any issues with our down light fixtures.
     

Share This Page