Monday, July 29, 2013

Since I last entered anything on this blog I had twin girls and my baby is now almost four years old.  How time flies!

Today I plugged in the Grundfos pump and after a few minutes felt the return pipe get very hot.  It was a cloudy day here in SF, so I took that to be a good sign.  Shortly after the pipe heated up, the flow dropped to zero even as the pump worked hard to move the water.   At this point I had only added five gallons of tap water.  The drainback tank is 7.5 gallons, the heat exchange loop in my SunEarth tank is 2.2 gallons and the balance of piping is maybe another 0.5 gallons.  That makes around 10 gallons of water to fully fill the drainback tank, which is above the height of the heat exchanger, pump and balance of piping.  After adding another ~5 gallons, the water flowed once more and the bubbles began to get smaller, then mostly disappear.

I used tap water to simply flush the system of flux and 'funk' before adding distilled water.

I found that I needed to run the pump awhile to fully charge the system.  I suspect air gets trapped here and there, and needs a good push to get evicted.

All the plumbing is finished.  I now need to:

1. Insulate the the inside piping.
2. Solder the temperature probe on the roof to the bell wire that I've run up to the panels and run that to the array outlet.
3. Find a source for outdoor grade pipe insulation and install.
4. Add Reflectix insulation to exposed parts of the drainback tank and add a layer of it to the storage tank.
5. Test the Steca controller and then choose settings for it.


Thursday, September 6, 2012

Panels Racked

 Two weekends ago Jeff (background) and Ron (foreground) from GRID Alternatives installed the panels on the racking system.  I helped out, but mostly just tried to stay out of their way.  Although I toyed with doing this myself with the help of a friend, it went so fast and smoothly employing Ron and Jeff.  They are the real deal!   Here they're surveying the roof for rack layout.  They discovered that my east-west running roof rafters had a few bends in them, resulting in a couple extra holes in the roof.  I wasn't worried as I knew the flashing and added roll roofing would plug them. Their tape is oriented 15 degrees east of due south. 

 Both chalk lines are snapped (fluorescent orange).  The bottom and top rails will anchor to the FastJacks that dot these lines.  There are a total of six them.  The sealent under the jacks is a Geocel roof caulking product (GeoGreen 4500?).  Stainless steel lag bolts hold the jacks to the roof.  Final tightening of the bolts is done manually with a ratcheting socket wrench. 
 Bottom end panels will be anchored at the above three jacks. 
Ron starts applying APOC 133 roof sealant around jack.   Behind him you can see the Oatey flashing that have been sprayed with the sealant primer - a sticky black coating on both sides. 
 Oatey solar roof flashings come next.   The above flashing didn't have the sticky spray applied to it, so we had to remove it and try again.  Over the APOC 133 we placed strips of fiberglass tape (not shown)  to help strengthen the sealant layer.

 Ron is using an inclinometer to make sure that the back rail will accomodate a 45 degree panel tilt.

The Oatey flashing and the area around it is covered in APOC 133, then the roll roofing material is laid over.  Each piece is 2'x2'.

The stainless "self-tapping" screws that came with the SunEarth RexRack did not want to penetrate the rails.  They're tough rails!  So were were forced to predrill the rails first.  We broke a total of three bits doing this.  Ron remarked that he'd not worked with such recalcitrant rail before.

 Ron checks the tilt on the lower rail, making sure that it was set properly to 45 degrees.
The back rail is fully installed.  

 The two 4'x8' panels are up and mounted.  The headers on these panels have not been coupled, they're just clamped to the rails.  Now it's up to me to sweat two couplers on the middle heaters to attach panel to panel.  On the outside headers I need to cap one on the top and one on the bottom.  The other two outside headers need 1" to 3/4" reducing fittings installed and elbows to point back to the supply pipes.  I need to determine if this system requires pressure relief valve or not given that it's a drainback design. 

Thursday, August 30, 2012

Goop on the Roof

 The roof penetrations for the plumbing are flashed and sealed.  The process involved:

1. Wire brushing the existing gravel surface of my rolled roofing. 
2. Applying a 3-5 mm layer of the APOC 133 roof sealant. 

3. Back buttering the Oatey `Solar' flashings with APOC 133 and sticking them on the roof.
4. Forgetting to pull the sensor wire through the flashing.  (DOH!)
5. Overlapping the flashing and threading them down the plumbing pipes. 

6. Covering the flashing with more APOC 133.  
7. Cutting a square of bitumen rool roofing to cover the goo.
8.  Peeling backing off roll roofing and laying it over the good.  

9. Rolling and patting down the rool roofing so that it makes a good bubble-free bond with the existing roof. 

I have some thin sheet aluminum that I'm going to use to make `parasols' for the rubber boots on these flashings.  Maybe instead of getting 10 years out of the rubber, I'll get 30.  As a result of forgetting to pull the sensor wire, I'll have to lift the edge of one of the boots and probably use a stiff wire to pull the bell cord sensor wire. woO.

Wednesday, August 8, 2012

Solar Roof Flashings

Yesterday I fitted up the flashings that I'll be using for the 3/4" supply pipes that go to and from the collectors.  As the pipes are quite close, the top flashing required some trimming with my yellow handled Wiss snips.  The cutout I made allowed for flush layup of the flashings.  My friend Ron at GRID Alternatives recommends that I seal these flashings with APOC 133 caulk as it's usually what they use on this type of roofing (aggregate on bitumen), over which I'll adhere a layer of bitumen.  Tomorrow I'll be going to Western Gravel and Roofing Supply to get tubes of this stuff.  Ron has agreed to come over to help racking the panels on August 26th.  There's some small chance that I'll make time to finish this project myself, but I'll probably wait for Ron as I haven't enough experience in racking panels, flashing, and finding roof joists under built up roof membranes.  More soon!

Tuesday, July 31, 2012


I'm not finding much time in the week to work on this, but I've made good progress nonetheless.  Most of the downstairs plumbing is completed.  The plumbing that is hooked into the house water supply is all sweated together and in operation.   The solar storage tank is now passing unheated water to the water heater.  All it needs now is have the solar heat exchange fluid (distilled water) pumped through it's heat exchanger.

The combination of short work windows and the need for hot water in the house made for some stressful times. I created a few leaks that were hard to put right.  Calling my friend Colin the Plumber was the right thing to do.  It was expensive, but I learned a lot watching him work.

Here's a incomplete list of mistakes I made:

  1. I sweated in two swing check valves.  They sweated into the system no problem.  Every time the washing machine demanded hot water with it's solenoid actuated valves it caused the swing valves to bang really loudly.  I would never suggest to anyone to use this type of valve.  Colin replaced them with valves that close quietly.
  2. I failed to read the instructions for plumbing in the Watts tempering valve.  On the cold inlet side you HAVE to have 8" to 12" of pipe coming up vertically into the valve body for it to work.  If you don't do that you only get cold water.  None of the hot supply is passed.  This is probably a good way to fail as passing solar heated 175 deg. water would be really bad.  However, it caused me to call in a plumber in the night to put in a ball valve on the cold supply side of tempering valve, until time could be found to plumb it correctly.  This was an expensive, stupid mistake.
  3. You should always use PTFE tape on pipe threads WITH pipe compound.  Tape first, then apply a generous amount of pipe compound.  I'll never go back to using only PTFE tape...
  4. I did not use two unions on the top of the SunEarth tank.  To begin with, I used none.  Because I had a leak on the pipe nipple on the inlet side (See mistake #3), I fixed that and put in a union.  The other side is not leaking and had no union, so when it comes to time replace the tank, it will need to be cut out.  At that time a union should be installed.
  5. I used a pressure relief valve that I had laying around on the solar storage tank, not the 210F PRV that was supplied by Solartrope.  That probably won't be a problem, but we will see....
Whew!  This phase of the project was Trial by Leaks!  I always want the second or third iteration of whatever it is I'm making, so I expected mistakes...

Solar Storage, Pump, Drainback Tank
The solar collector loop is still unattached on the roof.  It's sweated together in the garage and presumably I could test it by pumping water up to the rooftop.  It wouldn't be a full pressure test, but it would be interesting to see if the pump is capable of lifting the water up there.  I'll be pretty grumpy if it's not.

There's lots left to do, but the hardest bits are done.  The biggest deal is racking the panels.  That I hope to do in the next couple weeks.  If all the plumbing leaks are over and done with (big if), then most of the rest of the work is insulating pipes, hooking up the controller, and lots of little things. Little is good =)

Hot Water Heater, Tempering and Other Valves

Friday, June 8, 2012

Check Valve

Today I worked for an hour or so adding a swing check valve upstream of the three way valve.  The top of my storage tank has a nice spattering of solder.  It relies on gravity to stay closed when water is not flowing in from the cold supply.  Like the double wall on the heat exchanger, this is another system component that  ensures that water will never work backward into the city water supply.  The unsoldered 90 between the labelled ball valve and check valve will actually be a couple 45's which will clear a the upper vent pipe in the background without resorting to 180 degrees of bends.  The less pressure drop around this system, the better!

Wednesday, June 6, 2012

Valve Manifold

Last night I started plumbing in valves and pipe on the top of the SunEarth 80 gallon storage tank.  I took it slow as making a mistake here would be messy and slow to undo.  I cut and pieced together all the fittings, sliding the tank back against the wall to make sure that the manifold cleared the 4" vent pipe that it needs to fit beneath.  Then I trebly checked the valve arrangement against the system schematic.  This was made slow and somewhat confusing because the component placement and orientation of my schematic differs from how the system is actually coming together.  Below is the manifold all sweated together.
With any great luck all the sweated fittings are water tight.  Going copper to copper is easy for me.  Going from copper to chunky brass and bronze valves has caused problems for me in the past.  I've had ball valves `pop' apart into two pieces hitting them with too much heat.  They've leaked horribly when not heated enough.  So, I made sure to first diligently clean them with a tubing brush, flux, then I hit them pretty hard with heat and used plenty of solder.  To keep the PTFE valve liners from melting, I used a wet towel to bring the valve bodies down below 100 C immediately after sweating on the fittings.  Only putting this all under city water pressure will I be sure that I did a proper job.

In the back, upper left gloomy portion of that picture I added a ball valve above the drainback tank.

A couple week ago, I sweated and secured the piping in the attic.  I've not yet flashed it in and the panels are still just sitting on the roof propped up on bricks. I hope to bring in a buddy from GRID Alternatives to help me rack the panels "real soon now".
 Here's a pic of the secured pipes in the attic.  The `From Collector' pipe looks like it has a section of it that is not sloped enough to allow drain back.  It actually is, but the picture would have you believe otherwise.  Until I've run water through these pipes, I'm not going to insulate them.  Getting around this cramped attic, with it's live knob and tube wiring and itchy piles of fiberglass is no fun, but with any luck, I'll only have to visit it one more time.

Next move is to cut into the existing cold water supply line, drain the line, add a ball valve and enough tubing to `stub out' the run to the 3-way valve in the above photo.  I'll not hook this up until I'm ready to put the storage tank in place against the wall.  When this will happen is unknown because I have to wait for my wife and child to `step out' for a bit before I can turn off the house supply.  All for now.