I wonder if I can use the following bulbs to light varios areas of my
home where I like to have a lot of light:
400 watt BT37 Mogul Base Coated Horizontal Burn +/- 15 degrees High
Output Position Oriented Metal Halide Sylvania Light Bulb
(Sylvania MS400/3K/HOR 64498)
Our Part #: SL64498
Manufacturer Code: MS400/3K/HOR
Price: $93.99 Each
Case Size: 6 ($563.94/Case)
Light Output: 33,500 lumens
Energy Used: 400 watts
Average Lifetime: 20,000 hours
Bulb Type: BT37
Base Type: Position Oriented Mogul
Length: 11.5 inches
Well, the joke was great, but I am not planning to grow
weeds. Although I do have some house plants that could benefit from
some good light in winter.
I was hoping to be able to use them in my garage. I often work in it
and would like to have very bright lighting there, somewhat
approaching daylight. It makes things pleasant. I have some
fluorescent lights there, but would like even more light. Hence my
Essentially, I would not mind a visit from the cops all that much, I
have nothing serious to hide. I cannot see, though, why they would
decide to visit, but that's all beside the point.
The questions are, essentially, are they suitable for garage
lighting. Do they emit harmful UV and is their light pleasant for
I have no experience with MH lights.
There have been a couple of incidents around here (Portland / Lake Oswego,
OR) recently where Halide lights in school gymnasiums (ok gymnasia to the
Latin /reek scholars) had cracked outer coatings. The lights emitted
a_LOT_ of bad UV stuff; several students and teachers apparently suffered
serious and permanent eye damage. The exposure was over a several month
period, AIUI, and there was no obvious indicator that the bulb outer
coatings were cracked.
Me, I'd stay away from them in the home / garage / workshop setting.
And I say that living in an area where from about now to mid April where our
"daylight" is usually a cold wet grey cloudy dim mess. I like "bright",
but won't take unnecessary risks.
On Mon, 28 Nov 2005 09:36:14 -0800, Jim McLaughlin <jim.mclaughlin> wrote:
Thanks. You raised a great issue and I would not want to take any eye
damage risk. Would it make any sense to enclose them into some
appropriate (rated for heat input) glass diffusers of any sort? Glass
is a UV filter, right?
It looks as though going with more regular fluorescents may be more
I have no idea what, if anything, filters (or absorbs?) UV output from the
halide lights. More you filter it though, seems to me the more you cut down
the lumens / sq. ft. on your work surfaces. If you filter the Halide output
enough, you might as well be using regular fluorescents. The captal cost
on the fluorescents has got to be lower than the halides plus additional
filters. And the fluorescents adhere to th KISS principle.
I'd recommend the fluorescents for several reasons entirely aside from
potential UV emission.
- MH bulbs are _hot_. In a smallish area (a garage would qualify),
the directed heat will occasionally be uncomfortable.
- MH systems are expensive.
- Used as overall lighting in a relatively low-ceiling space, MHs
will have intense hard-to-miss super bright spots, which will have
you stumbling around with purple spots in your eyes.
- I'd rather not have MH bulbs in a workshop, where accidentally
hitting one will let stuff out that you don't want...
- MHs are somewhat more efficient than ordinary incandescents, but
not nearly as good as fluorescents, and as such, going with a lot
of MHs to get a lot of light is going to cost a fair bit to operate.
Your best bet is to use fluorescents as overall lighting, and use
floods or spot lamps in work areas where you need it.
I've built my shop with several 8' fluorescent fixtures for
overall lighting, and used a variety of quartz halogen fixtures
mounted on the ceiling for task lighting. In order to keep costs down,
I've used a few 150W and 300W rectangular QH flood lamp fixtures (long
skinny QH bulbs) - they're quite cheap. Even cheaper are simple
flood lamp holders with PAR30 QH bulbs (45-60W), tho you can up 'em
to PAR50s (up to 300W, but I'd stay below 100W because of heating
issues) if you wish.
Note that these fixtures are not normally indoor ceiling mounted,
and you need to be aware of the fact that they do produce a lot
of heat. The ceiling of my shop is drywalled... The inspector
didn't question them either.
Note also that I have to be careful not to run into them with
large pieces of lumber. Pot fixtures would be nicer, but they're
not as flexible. In 10 years or so, I've not broken one yet....
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
Chris, just what is involved in having a "MH system"?
The lightbulbs seem to just need light sockets. I would suppose tat
they need robust switches, maybe 0 crossing solid state relays. What
else is involved, especially with indirect lighting?
Yes. If I go ahead with them (doubtful at this point), I would use
them for INdirect lighting.
Thanks. My problem with fluorescents, is that there "never seems to be
enough". I already have 4 fixtures with 8 4 foot bulbs, and that is
barely adequate. I want to be able to feel great about the amoun tof
light that I have.
They need a ballast (big transformer), and a capacitor. They take
thousands of volts to ignite, and thus require special HV socket and
wiring from ballast to socket. The ballast will require cooling (fan of)
A fixture designed for indoor use should have a UV filter option, this
is generally a piece of heat tempered glass.
They will generate more UV than standard lights, so more fabric fading
It would be far easier to do it with 250 watt/U bulbs, since they are
more common, and work in any position.
For indirect lighting, you can get an outdoor fixture from a box store,
in the smaller sizes, that should work. At least enough to try it out.
My 400W MH fixtures don't have fans for cooling, just the back of the
ballast exposed to air. A lot of warehouse and parking-lot lights
use 400W MH without cooling fans.
A good fixture will include tempered glass that absorbs UV, I never
had a problem with fading with my MH living room light, and my
photographic light meter indicated less UV than daylight of the same
intensity. (That's still more UV than you'd get from a fluorescent,
but not a dangerous level.)
firstname.lastname@example.org is Joshua Putnam
Thanks, that's very interesting.
In your living room, which I hope is comparable with my 20x17 ft
garage, just how bright does it become with a 400 W MH light? Are you
somewhat satisfied, fully satisfied, is it bright like a day, etc?
I no longer have that living room, the MH lights I have now are
garage shop lights.
The living room was about 12x24, light intensity wasn't up to summer
daylight but was brighter than mid-winter daylight. (The room
occasionally doubled as a small photo studio, B&W only so I didn't
have to worry about color temperature.)
email@example.com is Joshua Putnam
The point I'm trying to make is that heat is a problem that needs to be
addressed, and that it will be a problem if you try and build fixtures
in, and not leave them out in the free air.
A small muffin fan is an easy DIY to do cooling, when one doesn't have
ability to design and test a better enclosure.
I have a dozen of 110v muffin fans, all highest quality stuff from
military equipment. Here's how I used one of them:
Using one sounds like a good idea!
What do you guys think about this fixture:
About that part about the especially high voltage:
MH fixtures include the ballast, socket and wiring in between -
Also, the high voltage starting is for the "pulse start" types, which
most 175 and 400 watt MH are not.
Pulse start has an advantage - it allows an arc tube lacking a starting
probe, and a "simpler cleaner" arc tube makes those are slightly more
efficient and have slightly better lumen maintenance - maybe a little
Ones with ceramic arc tubes have better color rendering and those are
pulse start - but I believe are mainly lower wattages.
- Don Klipstein ( firstname.lastname@example.org)
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