And Let the Piping Begin

   Well it had to happen sooner or later, I put to big holes in the side of the house.  But it wasn't as easy as I thought it would be.

   I purchased a type of holesaw called a SwitchBlade.  It is a neat design with replaceable blades.  There were two problems.  First, given the 2 9/16" hole that I was trying to drill, the shank required a 1/2" drill, which I have.  Unfortunately, the switchblade does not just cut the outer edge of the hole, like a traditional holesaw, it removes the inner material as well.  Which brings us to the second problem, the drill didn't have enough torque to drive the bit.  So the bit kept getting stuck.  As can been seen in the pictures, I tried making Swiss cheese our of the middle of the hole with a smaller bit, but this didn't help.  So, a $50 drill bit was set aside and back to home depot I went.

    Starting with a 2 1/2" hole saw that I owned. I managed to drill out the rest of the hole without stalling our the drill.  The important thing here is that a traditional holesaw does not grab.  So you can cut slowly.  Also, energy is only being expended at the outer edges of the hole and the middle is left alone.  This makes drilling more rapid.
   With the 2 1/2" hole drilled, I was a little worried.  I actually needed 2 3/4" hole, but now wasn't sure I could even use a bigger holesaw.  Holesaws work from a center pilot drill bit, but the center of the hole was missing, so no piloting.  But I purchased both a 2 5/8" and 2 3/4" bit and found that I could get them to enter the existing hole and have them self pilot based on the hole edge.  Success and another $50 spent for a total of $100 to make two little holes.
   What made this a little difficult was that I had to drill through the sill which on my house appears to be one solid 4×8.  They don't make them like that anymore.

    Supporting the pipes will be a little bit of a challenge.  Looking on line, I found no less than 12 different types of pipe hangers.  None of them seemed appropriate for supporting an insulated pipe.  Most pipe hangers support the pipe over a very narrow width.  If I did that with the insulated pipes, then the insulation would get crushed.
   So I decided to design some of my own supports out of bent aluminum sheet metal.  The image below shows one bracket that I used on the return pipe.  It cradles the pipe right up next to one piece of Misumi aluminum extrusion.  The support is 8" long and can spread the pipe weight over a long enough area to avoid insulation crushing.

   Then an alternative design was made for the supply pipe.  This is effectively a U-shape which I hung off of a short piece of 40×40 aluminum extrusion.

    The same design was used in a second location to support the supply pipe

    Frustratingly, I still don't have the long radius elbows that I ordered from PexSupply.  First they sent me the wrong parts, then the next order was held up due to some back ordered parts, and when I finally pushed them to ship the 90% of the order that was in stock (including the elbows), they had sold my elbows to someone else and the elbows were out of stock.
      But as it turns out, there was at least one pipe that I could get started on that didn't use the missing elbow: the supply pipe from the solar panels.  The supply pipe from the solar panels serves a could of different functions.  As it happens, this is always the highest point of the system, so it is important to put an air bleed valve there.  However, apparently these valves have a nasty habit of failing.  So just before the air bleed valve, it is recommended that you place a 1/4 turn shut off valve as can been seen in the picture.  Both the air bleed valve and the 1/4 turn valve came from Caleffi and are specially made for solar applications.  Although these items can be purchase from a place like Home Depot, they will not be rated for 275F or outdoor use.  These items were attached to a special elbow sold from Heliodyne.
   Also at this location, the temperature of the solar fluid must be measured.  So Heliodyne makes a special will "well" piece into which a thermistor can be placed..  I have not installed the thermistor yet, but when I do, I hope to run the wires inside the pipe insulation which should make for a very clean install.

 

  The first section of pipe was soldered together and is supported by one of the custom brackets.

 

   Also, the solar hot water thank is on order.  I chose an 80 gallon stainless steel models from Heat-Flo (HF-80).  It is expensive at $1800 (with shipping) but hopefully it will last forever.  I was really torn because A.O. Smith model SUNX-80 looks excellent.  It has less than half the flow resistance of the Heat-Flo.  If I recall correctly, the A.O. Smith model was equivalent to 18 feet of 1" pipe, the Heat-Flo was 60 feet, and the SuperStor was 250 feet.  I was amazed by how much difference in flow resistance exists between the different hot water tanks.   Hopefully I can get the 2.5 gpm flow rate that I need despite the high resistance of the Heat-Flo tank and the Taco Sentry Zone valves.

Hang that Heat Dump

  Initially I was just going to hand the heat dump form a couple of simple pipe hangers until I got concerned that it might pull out of the wall under the weight of the water.  But I might have gone a little to far in the opposite direction.

    Using Misumi 40×40mm extrusions, I constructed a couple of ladder type of supports that cost a total of $200.

   Using a Bosch hammerdrill, I made some 3/16" holes in the concrete and fastened the aluminum extrusions to the wall with tapcon concrete screws.  To get the two supports level. I used my laser level which you can see in the picture as a faint red line.

   The laser line was lined up with the screws of the first support, again with the faint red line.

    With the supports in place, the heat dump could be mounted to the wall.  So the aluminum fins don't get dented, plastic support pieces were placed between the Misumi aluminum extrusions and the radiant heaters.  The plastic pieces come with the radiant heaters and fit well on the 40 mm extrusion. 

   Only gravity is holding the heat dump in place, so thermal expansion should be easily accommodated.  However, the heat dump is fully captured by the aluminum extrusions and cannot fall off the wall.

Painful Shopping Day

   Gave myself a three day weekend to make progress, but I am afraid that all I accomplished was updating my model and shopping.  And boy did I spend a lot of money.

  $200 at Home depot for the 1" L copper tubing.  I know that getting the thicker (L versus M) and the larger diameter (1 versus 3/4") would cost more, but boy.

  $74 for a Caleffi expansion tank.  I already have a new Watts tank and planned on using it.  But the Caleffi pump station is setup for a 3/4" straight fitting and I couldn't figure out how to adapt it to the 3/4" NPT on the tank I have.

  $329 at PexSupply for all the 1" fittings that I need and I am also ordering 2 more Taco Zone valves to put in parallel with the ones I already have.  The taco valves are not "Fully Port" valve and have a great restriction which may kill the flowrate (GPM) in the panels.  On Taco valve is equivalent to adding 45 feet more pipe in the system.  Putting two in parallel should at least cut the resistance in half.  I won't know if this is worth doing until I get the system up and running.  Decisions, decisions, decisions.

   $400 at the Alt-E store,  $200 for the high temperature/UV resistance (armacell Solaflex HT) pipe insulation and $200 more for four gallons of propylene glycol.  So the contents of the pipe are $200, the pipe is $200, and the insulation is $200.  I didn't expect it to be this expensive.

   Getting close to the end.  I would still like to have HT 625 armacell adhesive and most importantly a $2000 hot water tank that I still cannot decide on.  It turns out that some of the good tanks have very high flow resistance through their coils.  Now I need to rethink.

Building the Heat Dump

  Once the hot water tank is full of hot water, one limitation of this type of solar system is that you must contend with unwanted heat.  If the propylene glycol/water mixture is left in the panels, it will overheat.  This can breakdown the propylene glycol and blow open the pressure release valve.  To avoid these problems, I am using a heat dump.

   From some dude on Craig's list, I purchased about 70 feet of baseboard radiators for $120.  These pieces are new and left over from plumbing jobs the gentleman had worked on.  I decided to run the radiators in parallel to reduce the flow restriction.  The heat dump consists of 10 parallel sections each 7 feet long.  This really should be overkill for this job.  But I wanted to make sure that I could shed the energy from a midday summer sun.

    I built the heat dump in two halves.  In the image below, you can see the front half.  The radiators are spaced at 5" from each other.  This plumbing is done with 3/4" copper sweat joints.  I created a wooden fixture to make sure the spacing and angle of the header pieces were just right.  Otherwise I might not have been able to assemble the finished halves together.

   The front and back halves were jointed together at the top with a 3/4"x1"x3/4" tee.  In this way the fluid can flow into a large 1" opening and then split into two 3/4" sections.  This should minimize flow restriction.  In the image below, you can see a "baseboard tee" which is really an elbow with a 1/8" npt female thread at the corner.  I am planning to put an air trap at that location.  There is a similar fitting at the bottom that will be used as a drain.

The completed assembly consists of about 60 solder joints and weighs 40 pounds (dry).  I need to pressure test it and then mount it on the wall.

 

Any guesses on how hot my basement will get when this thing is turned on?

The Panels Are In

   My three Heliodyne Gobi 406 001 solar panels arrived at my work the other day.  It was quite the event.  Work is in downtown Brookline Massachusetts which has very narrow streets.  Fedex Freight showed up to the site with a truck that was too large fit into our loading area (height restrictions) and no liftgate.   Fortunately we had interns.  Lots of interns.  They kindly helped me unload the panels and then reload them into my friend Doug's Ford F-150. 

    Of course I give my friend Doug crap for commuting to work in an F-150.  He drives at least one hour each way and probably only gets about 15 MPG.  Really kind of ridiculous.  But on days like this, I am glad he has the truck and willing to help out.

    The panels were shipped to my work to avoid added shipping fees.  When freight companies ship to a residence, they can tack on a $100 fee for the added difficulty.  They may tack on an additional $100 fee for a liftgate (sort of an elevator on the back of the truck).  To avoid these fees I shipped to a business address.

    One surprise with the panels is they are a full inch thinner than expected.  The panels were supposed to be 3.8" thick but are only 2.8" thick.   Apparently Heliodyne has come out with a thinner product line that is designated with "S".  So technically the panels are 406001S even though I ordered 406001 and the panel label says 406001.  It is frustrating to have that uncertainty in the ordering process, but in this case, it didn't do any harm.  In fact I think the thinner panels look great.

    The panels are so thin, that when Doug saw them on the truck he said there is only one panel, where are the other two?  Well all three panels were strapped to one oversized pallet, but with only 8.4" total thickness, he thought it was a single panel.

    The panels had to sit in my garage for a while, because I had not ordered the appropriate clips from Heliodyne.  Upon trying to order the clips, I found it almost impossible to figure out.  Alt-E (on-line store where I bought the panels) could not really help.  I think if you buy the Heliodyne racking system, they give you the clips.  But if you have made your own rack (like I did from Misumi extrusions) then you are on your own.

     So I decided to design and make my own clips out of stainless steel.  They are a pretty simple parts.  They only clamps down on the edge of the aluminum frame of the panel and have holes in the center for an M8 bolt. 

  To make the part, I milled one long piece of stainless steel on the bridgeport with the appropriate profile.  Then I came back and drilled the hole and cut off the individual parts.  The machining is less than perfect (as seen in the picture)  but it should work just fine.  Total machining time was four hours, which is way too long, but I am still learning my way around a bridgeport.  I was proud to be able to make them myself and the part is very sturdy.

   With the clips in hand, mounting the panels on the frame was quite straight forward.  Unfortunately I don't have a good picture because I immediately covered the panels with cardboard and tarp to avoid them over heating.  But trust me, the panels are under there and look great.

Rocks, Rocks, and More Rocks

   Sometimes I get a little depressed with the slow progress that I make on this project.  But then again, I am still glad to be doing it myself rather than simply writing a big check to a contractor.  Doing things myself provides a level of understanding and a sense of self worth that cannot easily be described.  In any case, I am marching forward.

   The work-site needed some cleaning up.
1) Remove the concrete forms.
2) Lower the dirt grade about 2" so that a rock finish could be added.
3) Put down weed-stopping plastic.
4) Put in plastic edging to define the zone
5) Add river stones
6) On the other side of the sidewalk, restore some top soil, add grass seed and fertilizer.

 The result of this effort, and hopefully you will agree, is a dramatically cleaned up look.  In fact it may be the best looking part of the landscape on the whole property

    On each end of the solar panel area, a small dirt area has been created for planting some greenery.  Hopefully this will offset the very industrial look of the installation.  The plants must not be too tall, however, or they will block the sun from getting to the panels.  I am considering hostas  but I don't know if they will work at this sunny location.

    The forms around each concrete pier have been removed.  I think they look pretty good.

   The site is ready for the panels.  I have even taken the tarp down now to get it out of the way of Hurricane Irene.