This week ended with two inspections scheduled for Tuesday, 09/07/10:  PG&E will perform the ‘mandrel inspection‘ and the City of Monte Sereno will inspect our mounting system and rough electrical for our solar photovoltaic panels.  We scheduled these inspections because we installed our 400 amp combined service entry device (400 amp electric panel) and all of the conduit and electric cables for the solar photovoltaic panels were run through to the appropriate points on the roof.

Bryan was confident that the weekly project review meeting tonight would go reasonably well.  Especially since he put two (2) bottles of Rombauer Chardonnay (Carneros 2008) in the fridge to cool …

Completing the Geothermal Ground Loop

The two-person team from 88HVAC, Justin and Michael, completed the test of our ground loop today.  Of the 25 concrete piers that go 30 feet into the ground with two U-tubes in each pier, we had one U-tube that failed (low water flow).  We could not solve the problem so we abandoned this U-tube and continued to connect all of the other U-tubes.

Bryan spent some time with Justin reviewing his recommendations for the valve configuration for our geothermal ground loops.  Justin presented several alternatives and they discussed each one.  The conclusion is that we will have copper pipe inside the house going to the underground concrete box in the North West corner of the house.  From this box, there will be HDPE pipes going to the four sets of concrete piers on the East and West sides of the house.

Although the copper materials have a higher cost, the labor cost will be the same or less to install the copper fittings.  Given the valves to isolate and control the water flow, copper fittings will have a smaller ‘footprint’ inside the flush mount concrete box.  The copper fittings will have a cleaner and simple layout and finish.

Background on Our 400 Amp Electric Service

We will have a 400 amp underground electric service.  Some people have asked, ‘with such an energy efficient house, why do you need a 400 amp service?’  The short answer is that there are code requirements that are a function of the size of the building footprint that determine the minimum amount of current that a house requires.  Since we do not have any natural gas coming into the house, we have electric cooktops and electric clothes dryers.  Although the calculated current is just under 300 amps, we will have a 400 amp service. Problems occur with too little electrical current, not more electrical current.

Mungo Hardwicke-Brown, who introduced Jo-Anne and Bryan in June 1991 when Jo-Anne was an Associate with Blake, Cassels & Graydon (now Blakes) in Toronto and Bryan was a Principal with Ernst & Young Canada, spoke with Bryan several times regarding our electric service requirements.  Currently, Mungo is completing a major renovation of his family’s home in Calgary, Canada.  Although he has a 200 amp electric service, he very much covets our 400 amp service.

The underground electric service enters our house through a 3-inch conduit.  This conduit goes through our concrete foundation wall and enters the bottom of our combined service entry device.  A ‘combined service entry device’ is the technical term for an electric panel that has an electric meter on one side and circuit breakers on the other side.  The side with the electric meter is only accessible to the electric utility and the circuit breakers on the other side are accessible to everyone else.  While we would have preferred separate components due to space constraints, the SU3040D400CN model from Square D (a division of Schneider Electric) is only 28-1/4 inches wide and costs less than a separate meter housing and distribution panel.

We will have four distribution panels, two of which will be in the East Mechanical room and two in the West Mechanical room.  One of the two panels in each mechanical room will house the circuits that will be connected to the transfer switch for our auxiliary backup natural gas powered generator.

Scott Andersen (from Toronto, Canada)  designed the electrical system so we could have two distribution panels in two different physical locations (one in the East Mechanical room and one in the West Mechanical room) that would work as one ‘virtual’ panel.  Scott, who has designed and built several unique lofts and homes in Toronto, completed the conceptual design for our house.  He is a partner with Burman & Fellows, which is an integrated commercial electrical contractor that focuses on grocery stores in the U.S. and Canada.  Scott designed the electrical distribution system to allow the auxiliary backup generator to provide power to circuits on each side of the house, the benefit of which would be reducing the amount of wire that needed to be run to the prioritized electrical circuits throughout the house.

Our electrical layout, as designed by Scott Andersen. Note the two auxiliary backup generator provides power to two distributions panels, which are joined and act as a 100 amp single panel.

Installing Our 400 Amp Combined Service Entry Device

Doug and Josh, the two-person team from Certified Electric, arrived on schedule to our project site at 9:00 am to install our combined service entry device.  They cleared their work area and reviewed the plans with Bryan.  Together, they went through PG&E’s electric and natural gas service requirements, which specify the electric meter and natural gas meter location requirements and the layout of the East and West Mechanical rooms.

Also, they discussed where and how the combined service entry device and other distribution panels would be grounded.  The Building Official for the City of Monte Sereno, Howard Bell, advised us that we could use the two of the 30 ft long #7 rebar to ground our electric service provided that the two pieces of rebar were more than six feet apart.  We had identified the pieces of rebar previously and Izzy had removed the concrete from these two pieces of rebar.

With a solid understanding of the site, PG&E’s ‘Green Book’ requirements, and our requirements, Doug and Josh set to  work laying out the conduit and then cutting the wood studs and exterior plywood/sheathing for the electric panel. 

The bottom edge of the new electric panel will be at the identical height as the original 125 amp panel, which was installed in 1969.  Given the larger size of the 400 amp panel, the top and sides needed to be cut. 

Nothing that a new sawzall blade can’t make happen …

Josh measures and lays out where the 3-inch conduit will go into the bottom of the combined service entry device.

Doug, using a new sawzall blade, cuts the plywood for the 400 amp combined service entry device. Note the location of the new panel is exactly where the original 125 amp panel was located on the East wall of the garage.

The completed hole ready for the new 400 amp combined service entry device. The plywood will support the panel until the framing is completed at a later date.

The back of our new 400 amp combined service entry device. The disconnect for our solar photovoltaic panels will be on the left side of the combined service entry device.

Our new 400 amp combined service delivery panel, as viewed from the exterior of the house.

Note the #7 reinforcing steel (rebar) that is exposed in the concrete pier. This is one of two locations where our electric service will be grounded to the rebar that goes 30 feet into the earth.

A completed concrete pier with our geothermal ground loop. Note the connection at the bottom of the photo, which connects the two U-tubes in the pier. Also, note the supply going into the first U-tube and the return coming out of the second U-tube.

The adjacent concrete pier, showing the connection between the two U-tubes and the supply and return connections.

The only concrete pier with a blocked U-tube. We are using the good U-tube in this concrete pier and have abandoned the defective U-tube. 49 of the 50 U-tubes in our 25 concrete piers were tested successfully for flow and pressure.

The East wall in the East Mechanical room. The seven wires in the box on the left will carry the current from the solar photovoltaic panels on our roof. The panel on the right is connected by 2-inch conduit embedded in the concrete to the opening in the Garage and to the West Mechanical room.

We are considering locating two electric distribution panels on the North wall in the East Mechanical room.

We have a lot going on … connecting our geothermal ground loop, completing all of our underground drainage from the roof to our cistern and setting up the infrastructure for our photovoltaic solar panels.  The last thing we needed was someone to place a SAM storage unit by our property on Winchester Boulevard.

Importantly, the two-person team from 88HVAC, Justin and Mike, worked diligently to connect our ground loop between each of the 25 concrete piers.

Governor Schwartenegger Signed AB 1500 Yesterday!

Yesterday, the Governor of the (Great) State of California, Arnold Schwarzenegger, signed Assembly Bill 1500, that extends the use of High Occupancy Vehicle in carpool lanes until January 2015.  The existing yellow stickers that were scheduled to expire on January 1, 2011 are extended and will now expire on July 1, 2011.  The new white stickers will expire on January 1, 2015.

On July 31, we put down a deposit on a Nissan LEAF so we’re looking forward to being able to drive in the carpool (diamond) lanes.

A Dangerous Situation

The SAM storage unit on Winchester creates a dangerous situation in two aspects.  First, the SAM storage unit blocks visibility for vehicles turning left or right from Via Sereno onto Winchester Boulevard.  Second, the SAM storage unit blocks the 25 mph sign on Winchester, exacerbating the problem.  Essentially, vehicles travelling Southbound on Winchester can’t see the 25 mph sign and vehicles leaving VIa Sereno can’t see them coming.  And, the vehicles are approaching faster.

There are 16 houses on Via Sereno, of which we are one, leaving 15 others.  A neighbor up the  street called us last night and mentioned that they thought our new SAM storage unit was blocking visibility on Via Sereno.  We corrected them promptly, explaining that the SAM storage unit was not ours.  Then, they asked if it belonged to one of the workers or sub-contractors that we were using.  No, it was not. 

If one neighbor called to ask us about the SAM storage unit, we could only imagine that the other 14 neighbors were thinking the same thing but didn’t want to call us, yet. 

Bryan took down the SAM storage unit number (420-200338) and called 1-800-GET-ASAM to advise the company that the person renting the SAM storage unit was violating an local ordinance.  They took the information and then called back within 10 minutes to say the person renting the SAM storage unit would move it by 12:00 noon tomorrow (09/02/10).

Let’s see what happens tomorrow …

Welding Our HDPE for the Geothermal Ground Loop

As part of our lower level (basement), we had to excavate 13 feet of dirt under our existing house.  Since we wanted to use geothermal heat exchange through a ground source heat pump, the shoring required for the excavation had tremendous synergies with the geothermal.

Since we needed a ‘ground loop’ for our ground source heat pump, we placed our HDPE (High Density Polyethelene tubing) inside the concrete shoring piers.  Each of these piers went 30 feet into the earth.

At this point, we needed to connect the HDPE in each of the 25 concrete piers so we could extract the energy from the ground (or put energy from the house into the ground).

First, the two-person team from 88HVAC connected the two U-tubes in each of the 25 concrete piers together.  Now, they had to connect each of the 25 piers together into four individual ground loops (two on the East side and two on the West side).

The process was very interesting to watch:

1. Measure and cut the HPDE to the appropriate length.
2. Chamfer and clean the end of the HDPE so the melting/welding would be consistent and uniform.
3. Attach the cold pipe (special tool) to the HDPE with the chamfer tool in place.  The chamfer tool ensures the pipe length is measured accurately.
4. Using the special heating tool, heat both the male and female ends of the HDPE tubing and slip fitting.
5. Remove the heating tool, and connect and hold the two pieces of HDPE for at least 10 seconds.

Easy-peasy, right? 

Sort of.

After making the connections, the system is tested to 100 pounds per square inch (PSI).  It must hold 100 PSI and not have any leaks.

Each of the steps in the procedure described above must be done perfectly, otherwise there will be leaks.

Leaks can occur wherever the welds (molten HDPE) are not complete.  If there are areas where the welds are weak then failures may occur in those places over time.  Again, each step in the procedure has to be done perfectly to minimize the probability of incomplete welds.  For example, the HDPE must be at the correct length otherwise it will be difficult to hold the heating tool for the correct amount of time.  If the heating tool does not melt the HDPE sufficiently then there will be a weak area or the weld will not be complete.

The team from 88HVAC took the time and paid attention to detail such that the welds were done correctly.

Measuring the HDPE to identify where to make the connection between the two concrete piers.

Cutting the HDPE to the correct length.

Chamfer tool, which removes the correct amount of HDPE from the corners of the pipe and allows the cold ring to be locked into the correct position that will provide sufficient surface area for the heating tool (weld).

Cleaning the HDPE where the weld will be made.

Clamping the cold ring onto the HDPE in the correct location.

Using the heating tool to melt both parts of the connection at the same time. Each step in the procedure must be done perfectly to weld each of the two pieces of HDPE together. This is a critical step.

After the heating tool creates molten HDPE, the heating tool is removed and the two pieces of HDPE are connected quickly.

The completed connection must be held in place for at least 10 seconds so the HDPE cools to create a complete weld.

Completed connection. This connection, done correctly, will last for the life of the HDPE, which is more than 100 years.

Looking North on Winchester Boulevard, the view of oncoming (Southbound) traffic is impaired, which results in a dangerous situation.

The 25 mph sign is blocked by the SAM storage unit on Winchester Boulevard.

Vehicles Southbound on Winchester Boulevard cannot see the 25 mph sign (behind the SAM storage unit).

Not seeing the speed limit, vehicles tend to speed up, exacerbating the situation for vehicles turing left (or right) from Via Sereno. This is dangerous.

The number of the SAM storage unit, which was placed in a dangerous location on Wichester Boulevard without a permit issued by the Town of Los Gatos.

To keep ahead of Izzy, who was trenching and putting our underground water drainage sytem in place, Bryan made three (3) trips to RV Cloud (which is only a couple miles North on Winchester Boulevard).

Two 'sticks' of 20 ft long, 3 inch ABS pipe for Izzy (this will take water to our 3,677 gallon underground cistern). Good thing we have a truck with an overhead rack!

The seven (7) electrical wires coming from the solar panels on the roof to the storage space under the pantry. These cables will be run to the solar inverter in the East Mechanical room.

During our remodel project, if you are driving along Winchester Boulevard and you see our U.S. flag flying, it signifies that we are on site and can host your visit.  Please drop by!

Our Visitors

Matt Jung, from 88HVAC is working on a project in Saratoga, CA and came by the project site to discuss our geothermal and radiant heat design.  He liked the hollow core concrete panels!

Matt Jung of 88HVAC checking in to see our progress. Note the two conveyors behind Matt.

Later, Trixi Menhardt and her mother came to see the status of our project.  They approved!

Trixi Menhardt (right) and her mother saw our U.S. flag flying and stopped by to see our new hollow core concrete panels.

We completed the west window bay of the temporary site office today. After returning today with the 6 ft. level and finding that, yes, the framing was square, we completed the window.

Ready for windows.

As well, the final 4×8 sheet of plywood was tucked into the south-east corner of the decking and screwed down. I convinced Paul Fulton to drop by the site and give me a hand positioning the plywood (more problems with the the tongue and groove. The deck is now complete (and the pipe is even painted florescent orange for safely).

Completed deck.

Just as I was about to leave the site, Matt Jung of 88HVAC returned my call.  We discussed the visit to Hi-Velocity Systems in Edmonton and how I was impressed with their product line.  Matt asked about the final radiant design and then asked me to visit a job site in Hillsborough on Monday.  He said that it would help to understand the alternatives that we are considering so we can finalize the design.

Monday will be a busy day.

Matt Jung of 88HVAC arranged for me to meet with Sean Provost of Hi-Velocity Systems during our trip to Edmonton, Alberta.

I met Sean at their offices on 124 Street and 127 Avenue and he took me on a complete tour of their operations. First, we reviewed a hard copy of our plans and discussed our requirements for air circulation in the basement. After reviewing the plans, Sean walked me through the relevant parts of their product line and showed me their demonstration models.

Following the product review, Sean took me on a tour of their facilities. Of particular interest was their training room and their test lab. Building a distribution network requires qualified installers so they have a set training schedule and dedicated training facilities.

Matt had mentioned that he attended a training session, which is how he got to know Sean.

I was impressed with the Hi-Velocity and, after leaving a complete set of house plans, left with a complete hard copy and electronic copy (CD) of their product documentation.

Next steps – Hi-Velocity will review the floor plans and recommend how to design and structure the ducting and return lines, including the outside air supply as well as the fan units.

Very cool …