Paul and Lily’s Home
When we started our business, we knew it would be paramount to have a great looking and high performance system in our home. Although we are only two people in the house, and consequently our hot water consumption was not as great as that of families with children, we decided to install a two collector system, in order to achieve the maximum value of our home for resale consideration.
One of the considerations raised by a lot of municipalities when asking about permitting is for there to be a structural engineers report signing off on the added load to the roofs truss system. This can be an added cost to the system and is thought by most people (structural engineers excepted) as being rather ridiculous because the weight of the panels is only about 115 lbs each (less than the weight of a man standing on your roof and which is spread over at least three of the rafters wide by eight feet or so long). The reasoning, we are told, is that the collectors have the ability to provide lift in wind conditions and extra loading in snow conditions. To our limited knowledge though, these reports usually do not suggest additional reinforcement and are therefore just an added cost without benefit.
Mounting the Viessmann 200-F collectors is usually straight forward. For our install, we used j-bolts to secure to the rafters (so as to avoid weakening the truss by drilling and lagging into them). The holes for the j-bolts are covered using flatjacks (next photo). The flatjacks provide a platform to which we attached a couple Unistrut members. The collectors are then clamped to the Unistrut making a very stable mount. The line set penetrations are each done with a roof boot and the exposed copper lines are first insulated and then covered with pvc cladding to protect the insulation from ultraviolet degradation. The sensor wire is likewise shielded from bird and rodent attention under the pvc cladding. This makes for a neat attractive addition to your roof. The cladding can be painted flat back if desired to further enhance the esthetic appearance of the installation.
Many manufacturers propose to lag directly through the roof cladding, leaving an exposed penetration with only roofers sealant as the means to prevent water ingress. This is not an unreasonable assumption, if you lag directly into the center of the rafter, and fill the hole with a good quality roofing sealant however the system is meant to last at least the life of the roofing material – will the sealant last that long? Although this seems to be a standard in the industry (and even with some roofers), Sun Bright Solar in speaking with the RCABC (Roofing Contractors Association of BC) and determined to offer the highest quality installations, goes a step further by covering this roof penetration using the Flatjack flashing. In this diagram, the threaded end of the j-bolt is drawn through the covered hole in the base plate. The “mounting block” in the lower diagram is actually a Unistrut channel which we would mount to the top of the flatjack spacer block.
The finished look of the flatjack footing. The base plate of the flatjack is liberally covered with roofers sealant for even further protection against water ingress. At present, we feel this is the best we can offer although there are plans to manufacture an even more secure penetration system in the future.
The next step in the installation is to run the copper pipes to the utility room. In our case, this was accomplished by drilling through the ceiling of the master bedroom closet (into the attic where the line-set comes from the collectors), then drilling into the ceiling of the utility room, creating a chase alongside the hot water heater chimney well. We liked this unobtrusive look although it is possible to run the lines through the eaves, down the exterior of the home and then into the utility room with a wall penetration. The exterior lines could be then covered by false downspouts. In this photo you can see we enclosed the chase with a wooden box beside the chimney although we chose the wrong color paint – not an big deal because it is nearly all hidden by clothes.
Next, we join the copper line set to the pumping station (top left of photo). An expansion tank is added to the system to allow for expansion of the heat transfer fluid during peak heating hours. In this photo you can also see the controller (above the expansion tank, RH) as well as some of the safety valves, backflow prevention valve, sight-glass, filling ports and air trap. These components allow for safe automated operation with very little attention required by the homeowner.
This is the heat exchanger (lower rectangular box) where accumulated heat from the collectors is passed to the domestic hot water in the solar storage tank. In our case, here in BC, the local regulations require that it be a “double-wall heat exchanger with visible leak detection”. This requirement is a bone of contention with many manufacturers and installers because it is not required throughout most of the rest of the world. There is considerable worry on the part of the regulatory bodies about installing solar here in BC that manifests itself in their requirement for expensive permits and professional letters of approval. In some municipalities, the local inspectors also require a backflow prevention valve be installed because there is some chance (1 in a few hundred million) that the double walls of the heat exchanger could fail simultaneously while they were putting out a fire in the neighborhood nearby causing a negative pressure in the cold main line into our home and thereby allowing for the possibility that the non-toxic component of the heat exchange fluid could enter into the city mains. Why only in BC?
Next we connect the solar storage tank via a bypass, to the homes hot water heater. This allows the homeowner to provide service to system should the need arise, without loosing the backup system. Note: Your conventional hot water heating becomes the backup in a properly sized solar hot water system because solar will provide in excess of 60 % of your homes hot water needs annually. You will notice these pipes are not painted purple (as were the solar lines). This is because they carry only potable water.
All the lines are covered in insulation to preserve the maximum heat gained from solar. You will also note that all the lines carrying the heat transfer fluid are marked as non-potable, should the event arise where you might be tempted to take a drink from one of them.
Although every home is unique, we will always endeavor to create a nice neat compact installation as shown here. We feel that if you have taken the first step forward to enjoy this free natural resource, we will make the rest of the journey as pleasant and rewarding as possible. We don’t tell you the installation process is without some inconvenience, because it does take up space, but we do promise to be as unobtrusive as possible. Enjoy your system and your decision to go solar.
Coming soon …data logging of energy savings from this system.