led lighting for brunnhilde

Good things come to those who waited. Sometime very small things make me happy and this modest investment and minor elbow grease is one.

By a large part, I refraint from jumping onto the early LED lighting bandwagon. For me it is not so much about the expense but the timing of the technology progression. In architecture and interior design, lighting is one of the least recognized aspects, at least in the non-participants. There is a lot more than what first meets the eyes in lighting design. Color temperature, light spectrum, direction, diffused verse direct, shadows, ambient versus task - to name a few. In fact lighting will give you the biggest bang for the buck in improving an interior through careful chosen product and installation, and placements. Lighting alone is one special profession in movie making and it continues to amazed me how often a movie or TV series is short changed by poor lighting not because of budget limitation, but simply the failure to harness the right professional.

In Brunnhilde's living cabin there are 4 halogen light fixtures. From the factory they are 20W each. While 20W is not exactly power slug by incandescent 's power efficiency, it is considerable when you  are camping and relying on the battery bank to power them. Upon my taken ownership I immediately swapped in 10W bulbs to cut the power consumption in half. The drop in illumination from 20W to 10W to human eyes is far less perceptible than what the wattage difference suggest because of the logarithmic response of (most) human sensory.

the four LED light fixtures in Brunnhilde

Why not switch to LED right away? That was 2 1/2 years ago and there were a few reasons to wait. At the time the choices of G4 drop-in LED bulbs were quite limited. The purveyors of these products were generally not reliable on what they claimed, or often the specifications were less than adequate for making an informed choice. Other concerns are reliability, cost, dimensional accuracy, and most important the light spectrum.

At the time the only viable bulb type for the hockey plug - like halogen fixtures is a disc type bulb. The disc diameter and depth is fabricated with the assumption it will fit inside most hockey plug -like fixtures. Problem is there is no standards that describe this bulb form factor. Very often the vendor failed to disclose the bulky components on the back side which make installation into most fixtures out of the question. One major drawback with the disc type design is the very narrow light spread inherent in LEDs. All the SMT LEDs are arrange to point perpendicular to the plane of the disc. This results in a narrow beam column. The design intend of the metallic reflector of the light fixture is defeated.

disc type G4 halogen replacement

an example of bulky electronic components on the back side - these are switching voltage regulator parts

Circa about 2 1/2 years ago the deal breaker for me is the light spectrum. Most early LED lights tends to be very cold (high color temperature). Even with the odd chance of finding one that claims warm white, the light spectrum is less than desirable for me. For interior lighting, I like the warm light spectrum of halogen lamps. Very often lighting vendors would at best provide a single number in color temperature to describe the color temperature. The problem is, for most light sources, it take a lot more than a single number to describe the light spectrum. Even by showing a spectrum spread with a single axis graph is sorely inadequate, unless it is qualified by the the degree of shading to signify the power intensity of each frequencies.

Fast forward to today. I decided to test my luck after carefully studying many alternatives on Amazon. They are so cheap now that I don't mind  a bit of gambling with informed decision. I selected this new kind of LED bulbs. They are very close to the dimensions of the halogen G4 they are designed to replace. I order a package of 6 (1.5W ones that replaces 10W halogen) which gives me 2 spares. Perfect! To keep things simple, I order the DC version.

$15 investment

the G4 hockey plug light fixture in Brunnhilde

i pulled out the fixture to make the installation easier - but it turned out only one of the fixture can be detached at the connector

the LED replacement is a few mm longer than the halogen bulb but fits nicely

The advantage of choosing this LED bulb type over the disc type is diffusion. These bulbs throw light in 360 degree directions so it does not defeat the purpose of the reflector of the fixture. These bulbs are very well built despite their low cost. They are enclosed in a soft silicon-like transparent casing that feels like gummy bears in your hand.

The proof of the pudding is the tasting. They did not disappoint. The light intensity is very close to my 10W halogen bulb. I am very happy that I waited. With these new bulb type I do not have to sacrafice on the diffused and well spread light pattern of the fixture design. The color spectrum is very close too to the halogen, though it has a bit more of the green tint (due to higher energy bias in the green frequencies) which is exactly what I am expecting.

I am a stickler on the light spectrum when it comes to lighting selection. I may seems odd at first glance. With this LED bulbs that are intended to replace the G4 halogen bulbs. Even the slight green tint bothers me. Why? I think it has a lot to human's built-in biologic clock. For most indoor lighting, with exception of intense working task lights, we prefers the warm spectrum (of course the spectrum constantly shifts form cold to warm as the sun descents over the horizon) of the setting sun. Hence we tend to prefer warm light spectrum for most indoor lighting. The green tint creates a sensory dissonance. I think in time one may adjust to it and find it less objectionable.

Since I brought up this subject, I hope I am not the few that found people using daylight bulbs in fixtures in front of their house ugly. To me they stand out like a sore thumb.

My next step after the installation is to conduct a short term reliability test. I left them on for a few days in case any die from poor infant mortality.  So far none fail.