As doctors we are trying to frame some domestic-level recommendations to simulate medium intensity daylight indoors for patients in bed without proper access to actual sunlight. This is also an important need for us personally since our house lacks natural light during many parts of the day and almost everyone agrees that sunlight is the best light. I am currently using an 85w CFL and find it lacks the proper color sense of sunlight, since such bulbs with 6500k color temperature emphasise the 'blue' end of the spectrum. This creates a 'cold' ambiance which is rather disturbing. I would appreciate a more natural and balanced color scheme, but 'warm white' bulbs are far too yellow to serve that purpose, so I am considering a combination of white CFL and warm white incandescent bulbs in a 80:20 proportion of light intensity to supply the 'red' end of the spectrum that is lacking with just the CFL.
In order to provide both ends of the visual spectrum as also uv rays and infrared, I was thinking of installing one 85 watt spiral CFL side by side with one 100 watt incandescent bulb in a pair of simple open fixtures controlled by a single switch. The color temperature of the CFL is 6500k and it is supposed to output 5000 lumens of light, while the incandescent bulb is 2700k and outputs 1500lm. Voltage = 220v and current = 5amp. Are there any technical or electrical factors that counsel against this arrangement? If anybody has tried something similar, I would like your inputs. All suggested improvements on this setup are most welcome.
Since regular intermittent exposure to real or simulated sunlight is beneficial for various health purposes including sleep rhythm, mood and vitamin D3 synthesis, our aim is to design a composite artificial light that is near as possible to daylight in visual effect, as also electromagnetic content such as visible spectrum, infrared and uv rays, without possessing the extreme intensity of powerful sunlight or the technological complexity of professional arena/street/stage lighting.
Commonly available domestic lightbulbs including fluorescent tubes, incandescent lamps, CFL and LED would be used in appropriate combinations for this purpose.
Although a color temperature around 5000k is said to be in the 'natural daylight' range, such lights are not readily obtained here in India, where the commonly available options are 3000k ('warm white', an outright yellow light) 4000k (labelled 'neutral white', but really a less-yellow shade of gold) and 6500k ('cool daylight', which appears very artificial and very white). In my personal experience, each of these color temperatures has its own distinctive 'color cast' and each by itself doesn't really simulate the visual effect of a neutral sunlight which has no color cast and basically contains all color temperatures in a graded proportion - a full spectrum lighting.
Although complex machines can indeed simulate sunlight, they are beyond the scope of our project. However, each type of ordinary domestic lamp does represent some important characteristic of an ideal sunlight. For example, compact fluorescent lights produce ultraviolet rays and regular incandescent bulbs provide infrared (heat), while LED can give a strong semi-directional glare: moreover, at least 3 color temperature variants are commonly available. In fact such lamps are actually being combined in multiple ways to stimulate and support plant growth indoors in the form of full-spectrum grow lights.
That's what leads me to seek the advice of the home improvement experts here: what is the best way to combine various household bulbs in appropriate proportions of color temperature and light output to create an accurate simulation of medium intensity neutral daylight?