In search of... digital displays

Bored with a perfectly running system, we've been twiddling with the controller dials, changing the max & min temperature settings for the two pumps (roof-to-heat exchanger and heat exchanger-to-storage tank).

Most solar hot water systems maintain a steady temperature with a standby electric system. Wanting to believe in the Sun, and to live with more awareness of Gaia's moods and seasons, we opted to leave the standby electric system disconnected. This had us wanting to know, specifically, how hot the fluids were at various times and in various weather conditions.

Reading the manual for our Goldline GL-10 controller, we learnt of the TD-GL, a digital temperature display. We printed and studied the manual off the web, and asked our installer, Mark, to order us one. Mark reported that this hasn't been manufactured for years, nor could he find us a used one!

What Mark could find, and we look forward to, is a controller by Steca. This should give us the digital data to better log our experience.

Waiting for rain

On Thursday, I ran into David K at Art & Truth on the Roof (organized by Cat N of WEAN) who asked: what happened to this blog? It seemed to have just stopped, in mid-stream.

Well, days and days of cloudless skies makes for a very successful (and boring) solar installation. Yes, we have hot water. And yes, as much as we may want. We await thunder showers to make this story interesting.

the Saturday scrap metal run

Saturday morning found us raring to go. After days, the sun was out. This meant not only a great day to make hay but also to heat water and hang laundry on the line!

Showered, we cleared the basement of the construction debris, and sorted various metals for our local scrap yard: Geppert Scrap Metals on Wayne Ave in Germantown. They're open most days till 2p, but call 215 842 0122 to check. Today's rate was $1 per pound of copper, $0.50ea per lound of brass, and $0.40 per pound of aluminum. We returned from the scrap run with an additional $30 in our pockets.

Up & running...

Friday 9 am - Mark arrived early, installed the sight glass, hooked up the electrical controls, and made a 50/50 blend of anti-freeze & water.

We used gravity to siphon the blend into the heat exchanger. Eight gallons later, the sight glass showed that the exchanger was full. Turns out only about 1.6 gallons of this is actually inside the collector on our roof.

We turned on the water, and miracle of miracles... there was NO leak in the plumbing work done by Afshin in the basement or by Mark along the outside and on the roof!






So, while the tanks were filling up, Mark & Afshin installed the new strut to hold up the collector, insulated all pipes from the roof down to the basement.

By noon, Mark was done.

Here's our well-insulated system in the basement. The small white barrel on the left is the heat exchanger, with the grey-colored 80 gallon storage tank to it's right. There are 2 pumps in front. One circulates the antifreeze between the collector plate on the roof and the heat exchanger in the basement while the other pump circulates the water between the heat exchanger and the storage tank. Note the dangling wire over the storage tank. This is for the backup electric system, which we've refrained from installing. We want to believe that the sun itself will be adequate for our needs.

Our old hot water system has been turned off, and is NOT feeding into our hot water line. Although we expect no problems with the new system, for now we've left it so that it's only a flick of a valve and re-igniting the pilot to pull it back into service.

5 pm - Afshin, ready for his first shower, was curious how warm the water was. So, using a kitchen thermometer, we learnt that the water had heated from 50 degrees F to 94 degrees F. Note that the afternoon had been partly cloudy.

Washing dishes later in the evening, Meenal found the water adequately warm.

The next morning, we checked the temp again before showering. It had dropped to 90 degrees F, but the shower still felt envigorating. Note that it was still partly cloudy and in the 80s.

All systems go... on Friday morning

The broken & missing parts arrived today. I now know that the broken piece of glass is called the 'sight glass', used to monitor the anti-freeze level.

The missing piece was the strut, used to mount the collector onto our rooftop. Here's the collector, propped up on lumber while Mark ensures it's at the optimum angle...














And then a closeup of the left strut (all aluminum) and the right strut, that we fabricated out of old black pipes from Afshin's salvage piles, until the missing piece arrives.

Lesson learnt: leave old system on standby

As we neared the final test, Afshin began disconnecting the old water heater, cutting old pipes off and having new pipes and fittings ready.

Discovering that the new system couldn't be tested, we realized we were in hot water... that is.. had no hot water system at all... Aargh!! As Marshall & Afshin began cutting new pipes to hook up the old system, Meenal began dreaming of a lever that would've allowed her to switch between the two systems.

After several hours, well into Friday evening, Meenal & Afshin had it: the old system functioning as before, with additional valves so when we test the new system next week, the old one would be ready and on standby. We should've known this from our IT days, migrating between software systems.

Lesson learnt: leave old system on standby, there's no hurry to dismantle & cart it away.

lesson learnt: inspect & have all components ready

One of the last pieces of the assembly was a cylindrical piece of glass, reminescent of a turkey baster. Unpacking it around 3p on Friday afternoon, Mark discovered it had arrived broken.

A replacement was ordered and testing the new system was postponed till next week.

Lesson learnt: unpack, inspect & have all components before beginning assembly.

The Diderot Effect in Reverse!

I just posted a piece about the new solar water heater, and how it came to be installed.
Diderot noticed that when he procured an elegant robe, his whole boudoir looked so shabby it needed to be redecorated. Hence the robe had many hidden costs.
Meenal and Afshin became distressed about how much energy their conventional water heater consumed when they cut back on all their other electrical appliance consumption!

...and onto the roof!

Finally, on Thurday afternoon, our solar collector arrived. Here's Mark & Marshall hauling it off the truck with Afshin looking on.

And here's Marshall, after pushing the collector from our first floor roof onto our second floor roof!

Friday morning begins with Mark on the roof, positioning the collector. And to the left, the collector's eye view of our garden, with Marshall waving.

water usage

Reviewing past water bills, we discovered that we used about 3800 cf each year. From an old issue of Eco-Structure magazine, Meenal learnt that architects design for 2300 cf of water used each year per occupant. Our two-adult household, at 1900 cf per occupant per year, is lower than the norm, but not outrageously so.

We also began asking... so what is 3800cf? When we buy a new toilet, we've looked for a low-flow one, around 1.6 gallons per flush. When we change shower heads, we've looked for low-flow heads, rated to use about 2 gallons per minute. Digging thru some literature from the water department, we discovered that 100cf equals 750 gallons. So each year, we use 28,500 gallons. And each month, we use 2,175 gallons. And each day we use 72 gallons.

Note that this is all the water used: both hot and cold. For drinking & flushing, bathing & cleaning. We estimate about a third of this to be hot water, or about 24 gallons a day.

What's your water consumption?

reincarnation thru reuse

Thu afternoon - Mark & Marshall have been outside, anchoring the pipes. Afshin refining the plumbing in the basement. Meenal learning about blogs with a little help from Betsy & Miranda.
A desk leaf Afshin had rescued from the curb will be used as a panel to mount all the electrical components of this project. Meenal couldn't resist drenching that old wood in linseed oil, giving it a final treat before the desk leaf became part of the house and this adventure.

Between the basement and the roof...

Mark deciding on how to secure the pipes enclosed in insulation plus downspout. And later, reviewing the job. Above right, see a closeup of the pipes as they reach for the roofline.Here's the other end of the pipes, entering the basement, thru the same window frame as our DSL line!

Federal tax credit

We've been asked about the rebate we got. It's technically a federal tax credit and we haven't received it yet. We hope to apply it towards our 2007 taxes this coming April. More about the tax credit can be found on the Energy Star website, which states "Tax credits are available for qualified solar water heating and photovoltaic systems. The credits are available for systems “placed in service” from January 1, 2006 through December 31, 2008. The tax credit is for 30 percent of the cost of the system, up to $2,000. This credit is not limited to the $500 home improvement cap."

plug for our installer

Sandy, also of the Weavers Way Environment Committee, asked who's doing our installation. So it's time for a plug for Mark Bortman, just starting out as Exact Solar. I met Mark on a cold February night, at a town meeting on Clean Renewable Energy Incentives at the George School in Newtown (way out in Bucks County) organized by Candido Rodriguez. Mark has apprenticed for a year installing systems in Costa Rica and is now gearing up for the rooftops of Southeastern PA.

solar hot water in... Cyprus

Turgut, a fellow member of the Weavers Way Environment Committee, wrote in from Cyprus, where he's visiting family right now. Solar hot water is very commonplace in Cyprus. According to some stats he shared from here, at the beginning of 1999:

• Approximately 92% of the households and 50% of the hotels in Cyprus had solar water heating systems.
  
• Cyprus is one of the leading countries in terms of installed solar collectors per capita, with 0.86 square meters (9.25 sf) of solar collectors per capita. Just for comparison, we're installing 40sf this week.
  
• The estimated current area of installed solar collectors in Cyprus is 600 square meters (6400 sf), and the solar thermal-energy production is 336,000 MW/year.

The assembly begins

On the left, the new storage tank, uncrated. It'll store 80 gallons of hot water, which, given our consumption, should last us 3 sun-less days.

As I understand, the water on the roof has antifreeze in it (much needed for our climate) and so this isn't the water we'd use to wash & bathe with! The solar-heated water therefore needs to give up its heat to the clean water in the storage tank, thus the need for a heat exchanger - the small white container between Afshin & Mark, who are discussing plumbing design with Marshall listening in.Jason is filming and all the while, asking great questions of Meenal & Mark. Jason wants to replace the aging boiler in their home with a solar space heating solution.Outside, Mark has been bending the flexible copper tubing to follow our roofline contour. The black casing is the insulating material. The solar collector plates haven't arrived yet, so we break for the day at 2. Afshin continues laying out the pipes and fittings in the cool basement.

Our old system

Our old hot water tank, swathed in it's shiny blanket for just one winter, will soon to be disconnected. Beneath the blanket was a yellow sticker stating this heater would consume about 250ccf of gas each year.

A solar water heating Bee

It's open house at Meenal and Afshin's as they take another step forward as eco-techno-pioneers. They are truly early adopters - the rest of us watch and once they figure out the bugs, then we start thinking of following suit.
Today the piping for their solar water heater is going in place. The holy grail - water heated at no cost (once the payback of 8 years or so passes) with no CO2 emissions from the electrical generation or gas fuel to heat the water - will be achieved.

Day One - Hour One

Today is going to be a warm day, I am sitting in the living room under the fan. Weather forecast for today is: Mostly sunny. Highs in the lower 90s. Southwest winds 10 to 15 mph.

We have a slow start, Mark cannot locate the solar collectors which got delivered to Allentown so he is running late. Marshal is here, we call Jason (he is going to record this installation)