Saturday, February 17, 2007

Fluorescent Recessed Lighting Spec Q&A

We were able to find someone who sells fluorescent lights w/ electronic ballasts, but they can accommodate only 18Watt.
Will that be enough for our kitchen?
What wattage do you normally recommend (13, 18, 26)?
Supposedly the store also sells cans that accommodate 13w lights.

I don't usually specify specific fixtures or wattage, leaving that up to the electrician, contractor and owner to decide.
The reason is that lighting is a very fast moving target these days, and most of my clients are not willing to pay me to research the issue.
It is MUCH more cost effective to hire a lighting designer than to pay me to learn enough to be able to advise you.
A lighting designer does this every day and, by definition, is an expert in the field and up to date.
I recommend Randall Whitehead, who inspired me to learn as much about lighting as I know.
He is in San Francisco and his web site is
Randall's philosophy on lighting mirrors mine:
He really believes in fluorescent lighting and knows how to make it beautiful.
He is expensive hourly, but very cost-effective when you already have a lighting plan and just need specifications...Far less than I would cost you to do it as well.
You can contact him and email your electrical/lighting plan and he can give you a price for doing the spec.

Now, to tell you what I do know (some of it based on a seminar a couple of weeks ago):
You should be able to find/order fluorescent recessed fixtures in 13, 18, and 26 watt bulb (lamp) sizes.
Electronic ballasts are not available in 13 watt (to my knowledge).
If you are going with electronic ballast (and you should because the older magnetic ballasts will soon be phased out), the 26 watt lamps and fixtures will give you a wider variability than lamps which are not as bright.

You should be able to install fewer fixtures if they are brighter AND have an appropriately wider beam spread to spread the light beam widest at 36" from the floor.
This is a function of the fixture, reflector and lamp all working together to achieve the desired objective.

If the 26 watt fixtures and reflectors are really designed for higher commercial ceilings, they won't do you any good because your ceilings are 8'.
This MAY be why you are having trouble finding them.
I do not know the answer to that question.
You need to ask it of a fixture manufacturer or lighting designer.

Imagine hanging a bunch of flashlights from the ceiling.
Each one projects a cone of light.
You want the widest part of the cone to fall at 36" from the floor (counter height).
You also want the light cones to intersect so that there are no dark spots in the kitchen.
Doing this effectively with an 8' ceiling is the most difficult way to light a kitchen.
The problem's answer will give you general illumination PLUS task lighting in a kitchen in all the areas exposed to such a lighting scheme.
It will also give you how much space between the fixtures, and thus how many fixtures you need.

Hope this helps a little.
Unfortunately I can not give you an easy answer to your problem.
So much depends on variables: fixture, lamp, wattage, reflector, beam spread, ceiling height, etc., etc., etc.
Remember, this is all supposed to be fun!