It is well known that orchids are shade-loving plants and you should not let them be exposed to too much sunlight. The damage to an orchid is enormous when exposed directly under the intense sun in the hot summer. Orchids thrive with 6 to 8 hours of bright indirect sunlight per day. They will work best if placed in an east or west facing window, depending on the orchid variety, where the sunlight is not too bright or direct.
Grow lights can be very useful for providing consistent lighting conditions, without the harmful heat of direct sunlight. To thrive, Phalaenopsis orchids need a lot of bright, but indirect light. Overexposure to direct sunlight can damage the delicate leaves of orchids, causing dehydration and sunburn that can lead to premature fall in bloom. During the summer, a sheer curtain creates enough cushioning to prevent damage from the sun; but these hardy orchids will also thrive if displayed inside a bright room or under the bright artificial light common in most office environments.
So what kind of light is strong light? It's bright, in bright sunlight; however, orchids don't like heat very much, so avoid areas that get direct afternoon sun (think that all windows in your house that shine brighter at lunchtime are bad for orchids). At a minimum, you'll want your orchid to receive five to six hours of sunlight a day, but you can still avoid placing it directly on window sills so that bright light can't burn the leaves. The amount of sunlight your orchid receives is crucial for it to bloom and bloom year after year, and here are three ways to determine it. Since orchids have adapted to life under the forest canopy, they are not used to receiving much, if any, direct sunlight.
If you want to display your Phalaenopsis orchid on a windowsill, windows facing north and west are best, as they provide the least direct sun exposure. Some of the most light-tolerant orchids, such as Vanda, Cattleya or Dendrobium, are able to acclimate to direct sunlight, as long as the foliage doesn't get too hot. The intensity of the light your orchid receives will depend on its proximity to a window and the direction in which the window faces. In general, they won't work well in direct sunlight, however, the amount of light needed for an orchid to bloom will vary by gender.
When provided with bright, indirect sunlight from a window facing east or west, orchids can be a wonderful and eye-catching, but low-maintenance indoor plant. There are some orchids that can acclimate to higher light conditions, however, direct sunlight, which is intense for long periods of time, would still be a problem. Trees generally protect them from direct sunlight, so they are used to receiving indirect filtered light. Increased sunlight can initially lead to more prolific flowering and even to re-bloom of the same flower spike.
Unfortunately, placing an orchid across the room from a window, or in a room facing north, is unlikely to provide enough sunlight. If a plant doesn't get enough light or too much direct sunlight, there are telltale signs to look out for. Therefore, in winter, you may need to bring the orchid closer to the windows because the days are shortened so that they get more sunlight. Place the orchid on a small table or in a nearby plant stand instead of directly in the window to avoid potentially sunburned leaves.