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Archive for September, 2009

iRobot Looj First Mission

Monday, September 7th, 2009

I just completed my first use of the iRobot Looj™125. The bottom line is, it was better than I expected.

When iRobot first announced the Looj, my reaction was along the line of “what were they thinking?” I couldn’t imagine that there was enough market in home gutter cleaning robots to warrant the R&D cost. But then we had new landscaping installed, and found a section being damaged by water overflowing the corner of one of our gutters. Candace said she’d fix that section of the flower bed, but not until I cleaned the gutters.

The Looj had reached its second generation by then, and they’re not that expensive, so I ordered one. Due to too many hands on my time, I only managed to deploy it this weekend.

Guess what? It works pretty well. It was not perfect, but it sure beat having to move the ladder every few feet. It plowed through the real debris with gusto. It was great for tree matter, etc. It was not quite as good with the several years build up of fine silt–it got most of that but left quite a bit behind.

This model is rated for 150 linear feet of gutter. I didn’t measure my gutters, but it handled the whole house on one charge. Now, it’s not a big house, and most of the gutters on the south side were mysteriously clean.

The unit had plenty of power. It would occasionally hang on something and flip itself over–but this model can run just fine upside-down. The only significant downside was that a lot of the spacer rods in my gutters were angled down too far, and blocked the Looj from its duties. I don’t blame the Looj for this; it was typically shoddy work on the builder’s part. On the other hand, if the Looj was made a little thinner, it would have fit under most of them.

Some other minor issues:

I don’t think the handle-remote was the best idea. It becomes difficult to remove and reinstall once the unit gets dust and grime on the handle rails. This is complicated by the need to hold onto the ladder while messing with it. The battery cover on the remote comes off too easily–I had to climb down the ladder to find my batteries more than once.

It sprays dirt all over the place–but I don’t see much way around that short of a built in shop-vac. You will need eye protection and a hat with a brim.

The NiCad battery needs too much babying–I thought we were past the days of having to pull the battery off the charger to avoid overcharging, and having to guess when the battery was fully charged instead of having an indicator.

But overall, it was a clear win over doing it by hand. I’m still not sure about the market for home gutter-cleaning robots, as I imagine I would use it once a year at the most. But I expect a single visit from a professional gutter cleaner would cost me more than the entire unit.

Incandescent Lights: What EISA Really Means

Friday, September 4th, 2009

There’s been a lot of press coverage recently of the incandescent lighting provisions of the Energy Independence and Security Act of 2007, and it’s largely been of the form “The US Government is banning incandescent light bulbs.”

While this makes for good prime-time newsvertainment, it’s not really true.

The tungsten light bulb was invented in 1905 as a fairly radical improvement on the earlier carbon filament bulbs, which would generally last less than a week before burning out. The humble incandescent light bulb was pretty constantly improved — both in terms of lifetime and efficiency — until about 1964. At that point in time, a bulb that used 100 watts could put out between 1,300 and 1,700 lumens. And that’s where we are now. The most commonly used incandescent bulbs have seen no real improvements in the past 45 years.

Now, let’s look at what EISA actually says about incandescent bulbs. A careful reading shows that it doesn’t eliminate incandescent bulbs. Far from it. All it does is set minimum efficiency standards for them. The relevant information comes from Pub.L. 110-140, Subtitle B, Section 321 (a)(3)(A)(ii)(I)(cc); the important columns from the table are:

Lumens Maximum
1490 – 2600
1050 – 1489
750 – 1049
310 – 749

The four lines in the table correspond roughly to modern 100, 75, 60, and 40 watt bulbs respectively. So, those are certainly aggressive compared to the ’60′s technology that we’re using today. But it’s not a “ban on incandescent bulbs” any more than recent automobile efficiency regulations are a “ban on internal combustion engines.”

In fact, you can already buy, right now in 2009, a number of bulbs that meet these standards. Sure, they’re a bit pricey right now, but so were 13 SEER air conditioners five years ago. When regulations force minimum efficiency standards, economies of scale almost always kick in and drop the prices to be very close to those of the older, less efficient technologies.

On top of this, we’ve seen some extremely promising advances in incandescent technologies, including laser treatment of filaments and coatings that turn waste heat into visible light. Either of these alone would completely blow the EISA standards out of the water, beating them by a margin of more than 30%. And there’s no reason to believe that they can’t be combined with each other for additional efficiencies.

So, before you start writing your eulogies for the humble incandescent bulb, I’d give the industry some time to show us what they can do when given a challenge.

Edit: there are additional EISA provisions that kick in January 1st, 2020; these require an efficiency of 45 lumens per watt or better. This will be more difficult, but the kinds of advances I talk about above are already close to this standard — the laser technique gets you to 35 lumens per watt — so even that isn’t likely to be incandescent’s death knell.