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Zero-warmup florescent fixtures do exist, but I've never seen them installed in a home. They work by continuously running a small current through the filaments
by thescriptkiddie 10y ago
Zero-warmup florescent fixtures do exist, but I've never seen them installed in a home. They work by continuously running a small current through the filaments to keep the bulbs warm, which requires a separate always-on power feed in addition to switched power. Normal (instant-start) florescents start producing light instantly, and in sufficiently hot weather don't need to warm up, but if it's below freezing expect less than half of rated brightness for the first five or ten minutes. It's worse for CFL bulbs than for straight tubes, and worse still for CFL bulbs installed upside-down because the mercury settles.
- kazinator 10y agoSo it's like the "stand by" mode of a tube amplifier, which keeps the filaments on. Even though fluorescent lamps are called cold cathodes, "[a] cold cathode does not necessarily operate at a low temperature: it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas." (Wikipedia, Cold Cathode). Obviously, the tech you're referring to requires a special circuit, since an ordinary light socket goes comletely open circuit when switched off. (I.e. anyone who claims to have these zero-warmup CFL's in ordinary light fixtures is confused.) I find that the slow warm-up time of regular CFL's is excellent for bathrooms. When you have to "go" at wee hours in the morning, you don't want the full glare in your sleepy eyes. Your notes about the ambient temperature effect on warm-up time are spot on. People who are not seeing the effect with CFL's may be living in a warm climate or well heated home.