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Recessed lighting, 20' ceilings

Posted by drtechno (My Page) on
Mon, Jun 1, 09 at 16:09

Hi gang!
I am researching recessed lighting for our upcoming house. One area that should be easy, but is turning out tricky, is the livingroom. Its roughly 24' wide by 25' long and has a 20' ceiling. The problem is with a ceiling that tall, I don't see info on wattage recommendations for the recessed lights. It would seem I would probably want ~125w bulbs incandescent to get any decent lighting. Still not sure how halogen would look, and I can't even imagine changing a halogen bulb if it blows.

Anyway, it seems to cover both the height and the size of the room, I would probably need 3 rows of 3 @ ~125w ? Or will 65w incandescent bulbs provide enough light?


Follow-Up Postings:

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RE: Recessed lighting, 20' ceilings

Curious where you would get a can authorized for 125 watts.
Study the decline in footcandles. Every 2 feet drops the ftcandles by 50%. Go to model homes and see what they are doing.
Bob


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RE: Recessed lighting, 20' ceilings

The only bulb that will do that job, and be used in an insulated ceiling is a 90par/sp halogen lamp.
This would require a 6" recessed housings with clear alzak trims.
You can change these lamps with an telescopic lamp relamping tool, which is available at most big box retail DIY's.
If you any other lamp you are just wasting your money.
You'll need at least 12 of the units.
Keep them away from the wall at least 3', and space them on 4-5' centres


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RE: Recessed lighting, 20' ceilings

Drtechno,
Look at the $32 GE Genura bulb. 1100 lumens initially and it is considered a 15,000 hour bulb. Designed for hard to reach areas. Is there another way to light this room besides recessed lights?
Normclc, What type of recessed can would be authorized for that very hot 90w halogen. The cans I have seen only go up to 75watts. I would like to find a can that is approved for more. To get greater light output and stay under the 75watt limit I am going to CFLs. There are some spirals that get higher lumens and are authorized for recessed lights. If a person can take the look of a par38 -90watt prism spot, I guess they could stand the look of a CFL. That's when the baffle you recommend would be worth it...to get the light out of the can. I still don't see the need for sophicated baffles and trim if a person uses a spot that is flush with the outside of the fixture. IMHO
Bob


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RE: Recessed lighting, 20' ceilings

Thanks for the info Bob. I will look into that bulb. I suppose we can light that room in any fashion, but because of the minimalist/modern design, no hanging lights would be suitable. Track lighting would work but would be a nightmare to change bulbs in (plus it would have to be pretty bright). With the insulated ceiling right above, heat generation looks like its going to be the limiting factor... But wouldn't even a large number of 65w incandescent bulbs provide enough light? It seems like they would.


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RE: Recessed lighting, 20' ceilings

On yahoo, search:

TCP floodlight specifications

Click on the link: Compact Fluorescent Floodlight Specifications

At the bottom of that page you will see what happens to light as you get further from the fixture. EX: a 65 watt
(650 lumens) at 4 ft from the bulb gives 10 footcandles; at 12 feet it drops to 1.1 ftcandles. Go up to 950 lumens (about 85 watts on their chart) and the footcandles double at the same 12 ft height (2.2 fc). The chart does not show 20'.

Like kitchens, recessed lights is the rage. But people have to add undercounter lights to get lights closer to the work surface. I suspect you will have to add wall scounces and/or lamps to get light where you really need it. More light from other sources will reduce the need to have super bright recessed lights, strong enough to get the light you will need to read by.
Another whole concept is to wash the ceiling with lights coming from lights behind trim so the light source is not visible, but the ceiling looks nice. Remember recessed lights will not brighten the dark ceiling. Then use lighting closer to the floor to put light where you need it.

Good Luck,
Bob


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RE: Recessed lighting, 20' ceilings

All major manufacturer's of recessed have a 6" double wall insulated can that is rated for 100 watts.
Most electricians, and all big box house brands only use the cheaper single wall housing rated at 75 watt.
Using the "inverse square"law, you will see that the same light bulb will only produce 10% of the light level on your horizontal plane( 36" off the floor) plane off a 20'ceiling compared to a 8'ceiling.
As a CFL is a linear source , as opposed to a point source,ie incandescent, there is no reflector made that will drive that amount of light down 17' to your vertical plane.
The only bulbs that can do the job are a 90par/spot and a 100parIR/sp.
Hence a6' recessed housing with your choice of these two lamps.
I would also suggest a number of wall brackets with light directed up into the space to negate the "cavern" effect that using only recessd lights will create


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RE: Recessed lighting, 20' ceilings

Normclc, Help!
I am searching for the 100watt can. Please list a name and model number, please. Or please give a link to the can. I will try to order it. I am particularly interested in this because the thermal protection switch built into the can should stand more heat. Even though I will be using a CLF which produces a fraction of the heat I still don't want the switch to trigger, plus I would like a more heat resistant can. Thanks
I did find this government post at www.energy.ca.gov saying that cans will not be greater than 75watts.

From: http://www.energy.ca.gov/title24/2005standards/archive/documents/measures/25/25_2002-03_RECESSED_CEC.PDF

Lighting: Recessed Lighting
Description
This change requires that recessed luminaries located in ceilings be designed to be air tight and rated, so
that insulation can be in direct contact with the housing. The lighting industry produces a class of
luminaire housings called ICAT (insulation contact air tight) that meet this requirement. Furthermore, if
luminaires are incandescent, they must be rated for 75 Watts or less. The following is preliminary language
to be included in 150(k).
150 (k)
Recessed luminaires installed in residences shall meet the following requirements:
1. Shall be rated for "insulated ceiling air tight (ICAT)".
2. If equipped with an Edison or screw base, shall have an aperture not larger than
5" and shall be rated for 75 Watts or less.
This measure would ensure that:
1. Ordinary 6" low cost, incandescent recessed "can" lights, rated up to 150 watts ICAT,
would be eliminated from the marketplace, preventing socket wattage from exceeding 75
Watts. Builders would be encouraged to employ the most energy efficient halogen
PAR20 and PAR30 lamps instead of inefficient R30 and R40 lamps, reducing typical
socket Watts by at least 25 Watts. Or alternatively, the contractor might employ low
voltage lighting, which also employs lamps of 75 Watts or less.
a. Most lighting installed in homes uses R lamps. The 75PAR30 produces as much
effective illumination as a 6" can with a 100-120 Watt R lamp. There will be no need to
add more cans.
b. The low voltage and compact fluorescent options are viable choices for individual
homeowners, architects and designers.
2. For situations demanding more light from recessed "can" lights, usually in kitchens,
builders would be encouraged to employ compact fluorescent "can" lights, which tend to
be more expensive on a unit basis than tungsten luminaires, but competitive to employing
additional 5" tungsten can lights, once labor and wiring costs are considered.
Benefits
This requirement would reduce heat losses through residential ceilings and also reduce lighting energy.
Heat loss reductions would result in lowered heating and cooling energy and may also affect the efficiency
of HVAC ducts. The change will save at least 25 Watts per recessed "can" light in conventional residential
lighting.
Environmental Impact
The environmental impacts of this requirement are positive, including the increased use of fluorescent
lighting in residences, which can increase mercury use. However, local increases of mercury are
outweighed by the benefit of reductions in air-born mercury at power plants.
Type of Change
This change would be implemented as a mandatory measure in 130 (hotel/motels) and 150 (low rise
residential). The Residential and Nonresidential Manuals should be updated to explain the requirement. It
would also be beneficial for the Commission to develop and disseminate a fact sheet to all electrical
manufacturers and distributors, prior to implementing the measure.
Measure Availability and Cost
All major manufacturers of recessed lighting in the U.S. produce, or could easily produce,
products to meet this requirement. Prices, availability, and selection of current products (e.g.
Halo H5 family) are consistent with, and to some degree cost less, than the 6" family equivalents.
Including trim, costs for builder-grade ICAT can lights are presently about $25 per luminaire more
expensive than the non-ICAT lights.
PNNL is presently funding the development of residential-grade, compact fluorescent luminaires that meet
these requirements. It is strongly believed that a reasonably-priced, ICAT dimmable downlight can be
produced using offshore manufacturing to cost within $25 of the current tungsten equivalent (about $75).
Useful Life, Persistence and Maintenance
This requirement will result in lighting systems that will persist, cannot be easily circumvented, provide
reasonable aesthetics and choice, generally enjoy longer lamp life than the base case, and permit dimming.
Performance Verification
There is no need for performance verification for this requirement. Typical plan checking and field
inspection prior to framing will be adequate to verify compliance.
Cost Effectiveness
This requirement is cost effective and calculations will be performed in subsequent tasks to demonstrate
this. For example, consider the following: Assume a home has 500 annual hours of lighting operation at
$0.15 per kWh for electricity. A compact fluorescent luminaire saves at least 65 Watts, as compared to a
100-Watt R or PAR lamp typically used in the 6" can, and produces the same amount of light. The
homeowner saves about $5 per year for each luminaire. If the cost premium is $25/luminaire, the simple
payback is about five years.
Analysis Tools
This requirement would be implemented as a mandatory measure and no analysis tools would be needed
for compliance purposes. For cost effectiveness calculations, a simple "Energy = Power x Time"
relationship will be used, coupled with data on typical lighting hours in residential applications, as well as
power savings between conventional luminaires and those required by this measure. The benefits of
reduced heat loss through the ceiling would be quantified using MICROPAS or CALRES.
Relationship to Other Measures
This measure is related to other high efficacy requirements for residential lighting.
Bibliography and Other Research
PNNL research on recessed compact fluorescent luminaires will be consulted. Apart from this,
manufacturers specification sheets will provide power and cost data.


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RE: my final thought Recessed lighting, 20' ceilings

Drtechno,
Norm is right the par bulbs do get the light down to the floor, fluorescents spread the light. How do I know this? I just walked into a number of stores at a new, cool Town Center outdoor mall in our city. I looked at the lighting in the cafe part of Barnes and Noble. I looked at the wall washes and use of light. I looked at a store that used both fluorescent recessed light and the bright beam par 38 bulbs. I saw how the light from the par38s were like spotlights when the light hit the floor and the fluorescent gu24s gave a soft general lighting effect. How recessed lights without supplemental lighting on the walls can create a cave effect. We ate at a Japenese place that used 65watt(printed on the bulb) recessed in their 10ft ceiling ; the place was dark even though the lights were reasonably close. The one small halogen spot over the fish pond was so bright that you could not look at it.
But that was me. Take a walk into 10-20 modern stores and look what they have done with their ceiling lights. Pick the effect you want and go with that.
Good Luck,
Bob


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RE: Recessed lighting, 20' ceilings

there are two American mfg's model numbers

Juno IC2 and Lightolier 1100IC with the trim of your choice
You should probably contact them.


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RE: Recessed lighting, 20' ceilings

Thanks Norm. I really appreciate the info. I will contact companies who sell these models and inquire about remodel versions. And surprising the prices were not bad.
Thanks again,
Bob


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RE: Recessed lighting, 20' ceilings

Sometimes the most obvious answers are right under our noses. Thanks bugbite! Excellent point. I will take a stroll through the mall here and take a look at the lighting used in some restaurants and bars this coming week. All fantastic ideas. Thanks for the info. I'll also look into the 6" dbl insulated 100w housings. Thanks for that info too.


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RE: Recessed lighting, 20' ceilings

Well I figured out what I need (I ended up at a furniture showroom with the same kind of ceiling height and windows as my house). Basically, to get the power I want, I probably want to do Metal Halide track lighting spotlights. Nothing else can throw that much light down there to get a spot light effect..


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RE: Recessed lighting, 20' ceilings

Glad you found something you like. I was driving past a HHGreg store today. My wife said " Look at those lights; are those Halogen?" We were on the road across the parking lot. I said, No, I believe those were Metal Halide." So it was interesting when I saw your post today. I don't know what Kelvin they come in but if they come in different colors compare them. I personally love the 3100K that TCP (also makes N:vision at Home Depot has in their CFLs.) I have seen different lamp manufactures claim their color was a spefic Kelvin but was way off. Get a single lamp from the company you pick and test it before you order the whole batch. Better still, find out the EXACT bulb the furniture store uses and get that bulb.
Good Luck,
Bob


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RE: Recessed lighting, 20' ceilings

drtechno

MH is usually not going to work out in a residential setting. Some of the issues are that they take a few moments to come up to full brightness and take even longer to cool down and restrike if you turn them off and back on. Pulse start MH lamps are fastest but we're still talking a couple of minutes restrike. They are not dimmable. There are also color quality issues and color variation issues.

Norm's suggestion for Par 38 halogen spot lamps is the tool of choice to light residential spaces with 20' high ceilings. To enhance the look of this I recommend a deeper housing than Norm however. I find the relatively shallow standard housings to not conceal the lamp enough with such high ceilings.

Here is a link that might be useful: Juno Aculux


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RE: Recessed lighting, 20' ceilings

Yea I think dim4fun is right, I use MH lighting in my reef fishtank and know that it takes a while for them to get to a steady state, and you basically can't shut them on and off. Even though they looked great in the store, it would be a pain in the residential setting.

I guess going back to the PAR38 halogen spots is probably the best idea. Probably spaced 6' apart and then wall washers + pendant lights added.

Never knew it would be so difficult to light.


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