Tuesday, August 30, 2011

So Long and Thanx for all The Fish!

Well, it's about that time, time to close down this blog and admit defeat. I had a look at my stats today and I've got around 7000 page views for all history. The blog has been running for about 3 years, so that is a pretty poor showing. And people rarely submit comments. According to The Lovely Wife, to get page views and comments, you need to go to other people's blogs and comment there. I've done that with a few, listed in the blog roll, but I've not had much success in attracting a readership. There are also not many blogs out there that generate the kind of content I've been trying to generate, which I suppose is no surprise, given the lack of readership  I've had. I suppose another factor is my tendency to become technical and include math. Most people would rather get a root canal than try to understand math.

I suppose I could rant here about all the attention (and investment) given to infotainment devices and various other IT toys, but I will decline. Since I understand why. It is far more interesting to talk about the latest Apple toy than about some energy efficiency improvement. I bought an iPad for my mother this spring and boy was it slick! Oh well.

As a practical matter, I don't have anything in the pipeline to report on. The system remodel we did was one of those relationship-threatening jobs that people talk about. Now I know they really exist. The results actually look pretty good, though we did miss a couple things. But I am not about to put them in. I have sunk enough money in this house and irritated The Lovely Wife too much. I have a few small items:
  • Reinsulate the solar thermal tank with aerogel.
  • Insulate the HRV system because the architect screwed up and put them in uninsulated space. Probably I'll do some temperature measurements first to make sure more insulation is required.
  • Maybe put in some quieter exhaust fans in the bathroom and laundry room with humidity sensors.
  • Maybe put in a 220V timer on the hot tub, so I don't have to manually turn it off and on.
  • Maybe put in a solar thermal energy monitoring system,  so I can get data on how much energy the solar thermal system is generating.
In retrospect, this is a healthy list of stuff. But since nobody seems to care about it, there is no point in continuing the blog.

So...in the immortal words of Douglas Adams:

Tuesday, August 23, 2011

Nissan Leaf

I was out of town for July and most of August, so I did not have an opportunity to post. But just before I left, at the end of June, our Nissan Leaf arrived. They originally told me that it would come in July, and I told them I would rather have Sept. but then they bumped it up to June so they could accrue the revenue in Q2.

The purchase experience was one big ripoff. Nissan assigned me Nissan of Sunnyvale as my dealer. I arrived in pouring rain, and the sales guy ran me through the features of the car, then we took a test drive. The Leaf accelerates really nicely, it is very peppy and drives like a sports car. That sporty feel will make it popular with young drivers, and it comes at a price that is less than half of the Tesla. Back at the dealership, they took me to the finance guy. And he sort of worked me over, managed to extract a whole bunch of extra money for "scheduled maintenance". Electric cars really have no need for that, but somehow, after a long and difficult day at work, I let myself get duped. I had heard vague rumors that Nissan of Sunnyvale ripped people off, but it didn't sink in.

Above is a picture of the car. It's a hatchback,  but there seems to be enough leg room in the back seat. I took 3 colleagues out to lunch, and the car behaved respectably. Enough acceleration, even with four engineers in it.

Below is a picture of the instrument display:
The car has three display areas,  one immediately behind the steering wheel, one in the driver's  line of vision with the speedometer, and a LCD where the nav system shows maps, in the middle of the dashboard. This display is behind the steering wheel and is showing that the car has 117 miles range, the parking brake is on, and it has 526 miles on it already. When you start the car, it plays a little Japanese themed tune, and fans the two colored displays on both sides,  like a Japanese fan. Cute, but after a while it may get old. Fortunately, they have a collection  of tunes  you  can have the car play, so it's possible to change. Maybe an aftermarket opportunity here, like cellphone ring tones 8 years ago?

Our charger comes from the EVProject, which is run by Blink. Above is a picture of the charger. We obtained the charger for free, as reported here. Sprig Electric from San Jose installed the charger while I was out of town. The charger is supposed to connect to the network via wireless LAN and report data from the car to the EVProject web site. My access point is protected with WEP2 and my wife didn't know where the WEP key was, so the charger remained unused. She used the 120V charger that comes with the car and, surprisingly, it mostly worked fine. If the battery is about half depleted, the car can recharge in 6 hours on the 120V charger.

Yesterday, I attempted to configure the network connection and ran into some problems. The unit found the DHCP server OK, got a DNS server address, and was able to obtain an IP address, but it still failed to make a connection. I called up Blink and they said that I had to bring down the firewall on my router and bring it up again. Fortunately, most computers these days have individual firewalls, so I had  no problem  with this. I would never, ever put my computer on the Internet without a firewall, it would be infected with malware in 5 minutes.  After I did that,  the connection was established and I could bring up the firewall again.

But yesterday evening, my wife told me that she was being thrown out of the network around every 15 minutes, which is exactly the reporting interval for the Blink. So something still isn't right. I called again today,  and the customer service rep told me that the Blink had stopped reporting as of 12 midnight, and, after checking my wireless router's model number, that they would probably need to provide me with another access point. I suggested they might want to use Google's WiFi network, but they said no. Google runs a city wide WiFi network in Mountain View. Anyway, I have no objection if they want to give me another  access point, so long as they don't insist on tuning it to the same channel. That would result in interference.  Also, I want it protected with WEP2 at  minimum and possibly even EAP/802.1x. We'll see.

All in all, I'm pretty happy with this car, despite the ripoff purchase experience. And my wife is even happier. I suspect that she may in the end be the main driver, though it is a much better fit for my commute. She has a 120V plug in at her work, whereas I don't, so it seems to make much more sense for her to use the plug-in Prius. But she thinks it is too big, and she likes the Leaf because it reminds her of the Fiat 500 she had when she was at the university, size-wise that is. It's a far stretch otherwise. The Fiat 500 had lousy acceleration, cheesy interior fixtures, and a primitive instrument panel. The Leaf is a class act, really nicely outfitted, with much more than  anyone could need. 

Monday, August 22, 2011

Retrospective on System Remodel

This post is a retrospective on what I think I've learned by the system remodel we did on our house over the last year. First a brief review. Our goals were to reduce the carbon footprint of the house as much as possible, hopefully to net zero energy, primarily by somehow reducing gas usage for space heating and hot water. We started out with a solar thermal hot water system that completely removed gas usage for heating in summer but required gas for an old tank-based gas heater in winter. We succeeded in completely eliminating gas usage for hot water though an on-demand electric hot water heater as backup, offset by solar PV. We did not succeed for space heating, however. Our original plan was to install a geothermal heat pump and also offset as much as possible of the geothermal heat pump with solar PV. As it turned out, we abandoned the geothermal heat pump for reasons discussed below. We did not have enough solar resource on our roof to offset the electricity usage anyway, or, at least, we could either offset an electric car or the geothermal heat pump but not both. We are able to offset the on-demand electric hot water heater, but, in the end I estimate that we will still draw around 1000 kwh from the grid with an electric car and use around 250 therms of gas for space heating and cooking (cooking only amounts to around 1 therm a month).

Of course, whether we really succeeded in reducing our carbon footprint so much remains to be seen, I'll be measuring our energy usage over the next year (including some new measurements on exactly how much solar electricity we are generating thanks to the new Tigo MPP balancing system and monitoring tool). But I think we did learn some important lessons about the process of green remodeling and the technology available today. Below, I've listed some lessons I think we learned from our system remodel.

Geothermal heating and cooling systems are a ripoff in Northern California
We paid $9K to get a design for our geothermal system before pulling the plug. Cost was one reason we decided not to do it. The entire system was originally spec'ed at $60K and it surely would have grown by at least 20%. Recently I spoke with a couple who moved into our neighborhood from upstate New York. A good friend of theirs runs a geothermal contractor there and they said that $9K was how much one would pay on average for an installed system, and the geothermal contractor didn't need any expensive design. Why is geothermal so expensive in northern California? Hear are some speculations:
  • There are only three geothermal design firms in northern California, one in Santa Rosa, one in Sacramento, and another one I know not where. With that little competition, they can charge as much as they want.
  • Given the more complex geology of California, the state needs to regulate it more and drilling is more complicated than in New York. But 10X more complicated?
  • Geothermal HVAC systems are priced as a premium product, for $5M houses in Woodside and not for your average - but still quite pricey by standards of the rest of the country - house.
It seems like there is a real market opportunity for operators in the rest of the country to expand into northern California and start taking some business.With a 10x price differential, a contractor could move in and undercut the competition. Even better, a nationwide contractor (if such a thing could ever exist) could get economies of scale and achieve even lower prices (but see below for caution).

Geothermal technology today is designed for cold climates and is not well integrated with newer HVAC technologies like HRV
The system they were proposing to put into our house had a huge 80 gallon buffer tank connected directly up to the ground loop. The system was designed so that the heat pump would run flat out, cooling or heating the buffer tank until the temperature was uniform, then shut down. Though they never really told me why the buffer tank was needed (despite my asking), I suspect it was because the pump could not withstand intermittent operation. If there were no buffer tank, in our mild climate, the pump would end up going off and on frequently. Since it would have had to start pulling 3 x 300 ft. columns of fluid every time it started, the pump would probably have worn out sooner.

On top of that, we would have needed a whole second air handling system and ducting, parallel to the HRV ducting we were installing, for the air conditioning (we have hydronic radiant for heating). I asked why the second ducting system was necessary and they just shrugged. Our house is designed in such a way that it would have been impossible to fit in a second ducting system. Fitting the HRV ducting was a challenge in and of itself. The original forced air heating had ducting under the house, but that was removed when we had radiant installed. It simply isn't possible to find an integrated HRV/geothermal air handler.

But recently I ran across an article on ductless air conditioning systems. The article was written with air source heat pumps in mind, but it could equally well apply to ground source heat pumps. The basic idea is to run the refrigerant lines from the heat pump to small air handlers (basically fans) in each room. Since the refrigerant lines are much smaller, this would have worked well in our case. We could have run two lines to the two HRV systems on opposite  sides of the house, and installed heat exchangers there. Except the HRV systems aren't designed with outside assistance for heat exchange...Oh well.

Embedded Global Warming Potential (GWP, Climate Change Potential, CWP?) does count
When I started the project,  I wasn't convinced the embedded GWP was such a big issue. By this I mean the carbon equivalent embedded in the products or processes used to do the work. My focus was reducing the carbon footprint of the building over the long term, since I figured that the building would  be around much longer than I will, and reducing the carbon footprint over that long a time period would result in big gains. What I missed was that some treatments with excellent carbon footprint reduction potential have such large GWP themselves that they can equal or exceed the carbon footprint of the carbon-based energy use they eliminate. Closed cell foam is an example. While I probably would put closed cell foam in anyway if I were doing the job again, I think I might have put in less (just the ceiling for example) and done the rest in open cell foam which has far lower GWP potential (but see below).

Architects, even those claiming expertise in green building, are by and large mostly interested in aesthetics and not particularly concerned with the detailed engineering and fact-checking necessary to achieve really energy-efficient buildings
We originally selected our architect because one employee of the firm was involved with me in a local city-wide sustainability initiative, and also because I had seen a house designed and built by the architect's firm that had a very high Green Point rating. This employee left the company around a month after we started the design process, and the owner of the firm, who we continued working with, exhibited less than diligent attention to our remodel. He tried to convince us of dubious enhancements such as a solar hot air heater. When we need heat here in northern California, it is usually raining and cloudy. Such technology is more appropriate for climates like in Boulder, Colorado, where they have very cold but sunny days in winter. He also routed our HRV ducting through uninsulated attic space, which very likely will substantially reduce the amount of heat recovery we will get. From a practical standpoint, this was probably the only way to get the ducts routed, but he could at least have then recommended we insulate the ducts with additional insulation afterward. As it was, I didn't realize the error until the end of the job, by which time, we were so fed up that I decided wait and install it myself later if heat loss from the ducting becomes an issue. I had to spend a substantial amount of time researching energy efficiency technologies myself on the Internet, because the architect simply disappeared after drawing the initial plans. After that, the project manager (aka general contractor) and his assistant took over, and they were even less knowledgeable and interested than the architect. On the other hand, I think if we had been building a 3000 sq. ft./$5M house from scratch in Los Altos Hills, the architect would have been all over it, with passive solar, etc., and we would have been extremely satisfied with the result.

So I have the impression there is a kind of market hole here of professionals who are both knowledgeable about how to do plans for extensive remodeling construction and interested and engaged enough in the technology of energy efficiency and  renewable energy that they are willing to do the detailed fact checking necessary to ensure that a project accomplishes its energy reduction goals. I would have appreciated some discussion of choices, with some detailed analysis of what they could accomplish for my home. I got none of that, except as I calculated it myself. There is now software for doing these kinds of calculations but so far as I can determine, the architect we worked with didn't have access to it, or, if he did, had little interest in using it on our job.

Construction "professionals" are not interested in green technology and energy efficiency, even when told that energy efficiency is the top priority, since they have been so ingrained to simply look at cost.
We constantly ran up against this problem with our project manager. He was always looking for the lowest bid came from a subcontractor that knew little or nothing about green building. For example, I specifically told him that I wanted a 7 kw system with MPP balancing. His assistant came back to us with a collection of bids from small contractors for systems sized at around 5 kw, and none of them had MPP balancing. The best I could get was one guy who proposed a 6 kw system using microinverters (I've discussed the problems I see with microinverters here).  At least, this guy was a professional. One of the bids was from a nonprofit who sends "volunteers" up on the roof. Considering that we had a roofing professional fall from our roof and injure himself, I wanted nothing to do with that one. The reason they came back with these systems was because they were trying to hit a cost objective rather than the energy generation specifications I set out for the project. I finally had to tell the assistant to call Tigo and ask them for recommendations about solar contractors. That's how I got connected with REC and they did a fantastic job.

Neither the project manager nor his assistant kept a close eye on the subcontractors. They never visited the job except to let the subcontractors in and lock up at night. Of course, I know that contractors are usually managing 3 or 4 jobs at once but there were a couple times when we had a specific green technology installation, like with the HRV or the thermal bridging treatment, where serious problems could have been avoided if the project manager had shown more interest and diligence in actually checking up on what the subcontractors were doing during the job rather than leaving it up the the manager of the company doing the subcontracting.

Most construction technicians know nothing about green building techniques and care even less.
After all, they are getting paid by the hour, and, unlike professionals, they don't take much pride in their work. It is just a job (note that this was not always the case, people in building trades used to take much more pride in their work 50 years ago). A friend in construction told me that a survey showed something like 60% of most people working in construction today have had a substance abuse problem,  and that the overwhelming majority did the work because they didn't think they could do or couldn't do any other. And, to a large extent, I believe it is not the fault of the people in construction, I'm sure they would in the end rather feel good about the work they do. Construction technicians have no incentive to upgrade their training, so many are operating on knowledge obtained years ago, which doesn't reflect the latest results of building science. There is nobody paying them to take classes in the latest technology, and, because they really  don't have much interest in their jobs except to earn money,  they're not about to spend any time or money trying to upgrade their skills on their own. I believe this is because, in the last 40 years, the increasing right-wing tilt to the American political and social scene has devalued the contribution and importance of skilled labor at the expensive of massively overcompensated executives. Even though many construction technicians earn good salaries, they don't take much pride in their work because society doesn't really value it.

In my opinion, this point is the most serious problem for politicians who propose government programs to increase energy efficiency in the existing housing stock (commercial buildings are different, there a clear bottom line case for efficiency and people being paid to oversee the process with the interests of the building owner at heart causes better results). Even if the money were there, the knowledge simply isn't. I checked the curriculum at our local community college and there are only three programs for people in the trades to upgrade their skills, with only three or four courses per program. There are no programs in solar PV or solar thermal installation, proper building insulation, or HRV installation. If you want to learn about solar PV installation, you need to drive to Hopland and take courses at the Solar Living Institute. The Solar Living Institute has some excellent programs, but I don't understand why the knowledge for green building isn't being taught more widely. If we really want to achieve an 80% reduction in carbon footprint of our society by 2050, we have to work with the housing stock we have.

So there you have it.

Wednesday, June 22, 2011

Heat Control

The last few days here in Silicon Valley we have had temperatures in the upper 90'sF. Today, it cooled off substantially, but the heat gave me an opportunity to see how our newly re-insulated house performs in hot weather.

What I did was open all the windows up at night and let the house cool down. After the first night, the downstairs cooled down to around 70F, the upstairs to around 72F. After the second night, the downstairs cooled down to around 72F and the upstairs to around 74F. It seems that the thermal mass of the house didn't shed much heat during the night without some moving air (like with exhaust fans) to encourage it.

During the day, I closed all the windows with the exception of the skylight window. The house was not uncomfortable. The upstairs was at 82F the first day and 84F the second. I can say that this performance is much better than we would have seen without having done the reinsulation. The upstairs would have been into the upper 80's.

Today, I tried closing all the windows and  running the HRV all day, but it did not help much. The inside of the house was in the 80's, up to 81 upstairs, though the outside temperatures were way down, in the mid to lower 70's. I wonder if that had to do with the fact that the ducting for the HRV's runs through uninsulated attic, which could be expected to heat up substantially?

I hope to find out in the fall, when I am planning to install some wireless sensors to see. If it turns out to be so, I'll look into heavily insulating the HRV ducting.

Thursday, June 2, 2011

Plastic Packaging

Well, it seems retailers are finally doing something about plastic packaging. If you recall from this post, my purchase of new LED and CFL lights for our new light fixtures caused a mound of plastic packaging to materialize on the Buddha room floor by the time I had finished installing them.

As it turns out, the increasing price of oil makes the plastic clamshells that are ubiquitous in retail more expensive. So retailers are working with manufacturers to reduce the clamshells and use more paper, which is cheaper, renewable, and recyclable. This article in the New York Times (possibly behind a paywall) has more.

And it is about time too. Some of these clamshells are so thick that you need a pliers to open them.

Thursday, May 26, 2011


Well, after 11 months, our system remodel has drawn to a fitful conclusion. The contractor spent the last month going through the "punch list" of items like cracks along tile/wall joins that needed fixing. In the end, I simply left a couple of small items involving paint finishing because it was time to call it done. They still need to send the final bill with my contingency returned. Now comes the interesting part, measuring how well the improvements we made work.

I have one data point already. Usually for the month of April our electricity bill showed something like minus 6 to plus 12 kwh usage, depending on the amount of sun. This year, we had a whopping  minus 500+ kwh, the impact of our new, more-than-twice-as-large solar PV system. Since we don't yet have our Nissan Leaf, the power is simply going back into the grid. We've just about eliminated the big bill from Feb. when we had to turn the electric floor heating on in the sunroom and upstairs bathroom over a weekend to reduce the amount of moisture from wet drywall mud and we had no solar panels. Unfortunately, the Leaf won't show up until July so we will have a couple more months of large surpluses before we start balancing out.

Naturally, the solar thermal hot water system is cranking too. I turned the temperature down on the tank to 130F to avoid damage to the Stiebel-Eltron electric on demand hot water heater. The company claims it is rated up to 131F. I am wondering if I can instead simply turn the electric hot water heater off for the summer and keep the solar thermal tank at 180F, or if that temperature will damage the electric heater when it is off, but I probably won't try it because the Stiebel-Eltron was expensive. Not that it matters for the water we use. The mixing value brings the temperature down to 120F anyway, but keeping the tank extra hot reduces the overheating strain on the heat transfer fluid, and reduces the probability that a couple days of cloudy weather will reduce the tank temperature below 120F where the electric on-demand heater will cut in. I still need to reinsulate the tank, since the plumber destroyed the fiberglass batt blanket I had installed. I am planning on using aerogel insulation. Should be interesting, aerogel is a new material with some promise, but still pretty expensive. Fortunately, I don't need much for the tank.

In a few weeks, I want to write a retrospective about the job, and also do a piece about reinsulating the solar tank with some pictures I'll probably also have something to say when our Leaf arrives. However, inevitably, the frequency of my postings will be reduced now that I don't have much to blog about. Thanx to all my loyal readers who have pushed my page views up from single digits to low double digits.

Sunday, May 1, 2011

New LED Lights

One of my very first posts (here, published in November, 2009) was on a new LED light bulb. Though it was advertised as a 60 watt equivalent, it is 40 watts at best. These bulbs being what they are (namely, that they last 50 years) I still have both bulbs in light fixtures in areas that don't require much light.

Last weekend, I was busy collecting track light fixtures and bulbs for our new track lights at Home Depot and I ran across new LED bulbs that are also rated at 60 watt equivalent, in a indoor spotlight form factor.  These bulbs are, like the ones I bought 2 years ago, not cheap: $50 apiece, but they are supposed to last 50 years, for $1/year of light. Contrast that with CFLs, which run around $10 and are supposed to last for 5-8 years, for around $1.25-$2/year, and the LED lights seem a relative bargain. But, having been once burned, I was twice shy so I took the plunge on three: two large spots and one small one.

The large spots are Ecosmart brand, marketed by Phillips but manufactured by Cree:
 Unlike the Pharonx bulbs, these have a large plastic fitting around them, maybe a heat radiator?:
Here you can see it installed in one of the track light heads:
The bulbs might be ecosmart, but the way they are delivered was ecostupid. Here's the trash that was left over from one bulb:
I also bought a small spot, equivalent to a halogen bulb, for a pendant lamp for the upstairs front bedroom. Here you can see it next to the halogen bulb it replaces:
The halogen bulb is rated at 50 watts while the LED is rated at 5, for the same amount of light.

For the rest of the track heads, I bought a discount box of CFLs:

Strangely enough, I have to say I like the CFLs better. Contrary to what most people say, the light they give off is softly diffused and slightly yellowish, while the LED light is white and glaring, like normal halogen or incandescent spots. Since we use  spots through out the house, not having them glare into your eyes when you happen look their way is important. CFLs don't seem to glare as much.

When I was done with my task of separating the bulbs from their packaging material and installing them, I was left with a big pile of trash:
That's three subpiles: film plastic,  thicker plastic bubble wrap, and cardboard.  Theoretically, it is all recyclable and we have good recycling in our town, but did they have to include so much?