Thanks again to everyone.
Based upon the input here and discussions with my wife, I have figured out the plan below. Im still up in the air about alot of this, but I need to order stuff by Thursday so I'll be making a decision one way or another very soon.
I agree completel with the sentiment that poorly designed lighting is annoying. So I'm trying to do my best to avoide having it. I would appreciate any questions on the proposal below.
The room is 21 by 11 feet with a 7.5 foot ceiling, so light won't spread as far as with higher ceilings. 18 fixtures arranged in 3 rows of 6 fixtures per row. The first row is 2 feet from the back wall, and the next two rows are spaced 4 feet apart (but the spacing along the 21 foot dimension is 3.5 feet). This makes the fixtures look even. The baffles will all be black stepped, to try to reduce glare (I hate glare). The room has two pocket doorways into it, one at the front end and the other near the middle. The TV is going between them, so it’s off center. It’s a Samsung plasma, which is 4 feet wide (I forget the official screen width – 50 something).
Five of these fixtures will have low voltage MR16, 74W lamps with a 36 deg beam spread. These are designed for reading when people are sitting on the couches that are right below the fixtures. The beam spread will cause light to appear across the entire length of the couches, although the fixtures are spread too far apart to have the light even across the entire span. These 5 will share a 1,000W Vizia RF dimmer and probably not be used except when task lighting below the couches is needed.
The remaining 13 fixtures will contain 50W PAR20 lamps with a beam spread of 42 degrees. At 7.5 feet, that puts the half power light at a little over 2.5 foot radius. With the fixtures spaced 4 feet part, that will cause the light to overlap as it weakens and, I think, should provide relatively even lighting across the entire floor. If I use ICE PAR bulbs that should help more, I hope.
Since the room is so long and narrow, the three lights at the extreme end away from the front will have their own dimmer and probably not be used too often.
That leaves 10 fixtures. I am trying to decide how to be able to have a little lighting for TV watching without having glare on the TV. My idea was to split these remaining 10 lamps into two zones. The six in the middle could be their own zone, while the two in the very back of the room and the two in the very front but about 3.5 feet from each edge of the TV another zone. I am hoping that these, because of their angles and distance from the TV, when dimmed won’t produce a glare in the TV screen.
I am worried about the lamps that are on glaring on the TV, even though they will have the stepped baffles and a beam spread that should keep them away. Any ideas on how to prevent glare?
I expect that the PAR50 lamps will provide enough light, although they do poorly in my kitchen. Then again, those are R50, not PAR50 so the PAR lamps should produce more light. The numbers say it should be more than enough light, but I’ll be adding fixtures to my kitchen during this project in an attempt to brighten it up a bit, since it is just too dark. With these housings, 50W in a PAR20 is the max I can go. I expect you’ll all say it’s plenty of light, or too much light. Please let me know your thoughts on that.
The PAR20 bulbs will be fairly warm from a color temperature standpoint, creating a reddish effect similar to incandescent. That should be okay, as this room is already brighter than the kitchen, which has a very dark floor and countertops.
The PAR20 lamps make quite a bit of heat and they are not recommended for ceilings less than 8 feet high. We have R20 50W lamps in my kitchen and we have not noticed an objectionable amount of heat from them. Still, these are PAR lamps, not R lamps. Does anyone think there will be a big difference heat wise?
The MR16 lamps should produce a much whiter light suitable for reading and such, and much more light per watt. But the uneven nature of how it’s laid out on the couch is a bit of a concern.
Good quality MR16 lamps should send 85% of their heat up, not down with the light. Of course, I live in a two-story house, so I am essentially sending the light up into the ceiling, which is the floor of the second story. The housings will be non-air tight, although I have not looked into air tight housings to see if I should use them yet. Comments on this?
Finally, I am thinking of just using 75W MR16 bulbs everywhere. They can be dimmed most of the time to whatever level everyone likes and there would be no question of there not being enough light (like a blinding amount). The heat would go up, not down (which is either a bug or a feature – I don’t know which). The whiter light color would make the colors in the room look more natural without shifting them to the reddish end of the spectrum. It’s a bit more expensive. This adds about $230 to the lighting project.
Maybe instead of 50W PAR lamps I could use 50W Low Voltage MR16 lamps. This would be less light and whiter color.
So may options…