this is a direct repost of the message on simplysolar in case anyone else is reading that --
My last update was that the inspector was going to look into the actual code that he had originally rejected based on something he heard at a conference.
Today I got a pile of paper work with the requirements including his checklist.
His check list is
1 - Panels be securely attached to the roof as per manufacturers specs
2 - heat exchanger/back flow prevention to be installed.
- Double wall heat exchanger - with leak path to atmosphere
- single wall exchanger - must meet BCBC 7.2.10.13 (which just says must meet CSA-F379.1) and a minumum of 2 RPBA's for premises isolation and cold water supply to system.
3 - Solar storage tank
- seismic restraint ( 2 straps located top and bottom 1/3 (BCBC 1.1.3.11)
- Tank on drain pan (BCBC 7.6.1.7.(9)(10)
- Temperature and pressure relief valve (BCBC 7.6.1.7.(1)(2)(3))
- relief valve discharge pipe to acceptable drain (BCBC 7.6.1.7.(1)(c))
- Air vacuum breaker(BCBC 7.6.1.7.(8))
4 - Tempering(Mixing) valve on domestic hot water supply CSA F379.1-88(7.3.1)and CSA F383-87-(7.4 & 12.1)
5 - signage and labeling.
- piping or insulation shall be identified by markings that are permanent, distinct and easily recognized (BCBC 7.7.2.1)
6 - Thermal expansion to be installed
- solar system pressure loop (CSA F383-87 (7.6.2))
- Domestic potable water system (BCBC 7.6.1.11.(1))
7 - Solar system piping to be adequately insulated CSA F383-87(10.1)
8 - Solar System requires a presure relief valve (Setting ___ Psi).CSA F383-87(7.3 & 12.2.2)
- Pressure relief valve discharge pipe approved for high temperature
- Discharge pupe to metal holding container labeled 'Non-Potable' CSA 383-87 (7.2.4)
9 - System parts to be certified and approved (BCBC 7.2)
10 - All plumbing connections completed by a qualified plumber(BCBC 7.1.4.1.(1)(a))
11 - Engineer design drawings required (B-1.B-2.C-B) At the discretion of the authority having jurisdiction
At the bottom it lists
System Installation Requirements/Good Practices
Panel Orientation - facing south as directly as possible.
Minimum of 3 shut-off valves to allow for bypass of solar heating system.
Air vent to be provided on Solar Heating System at highest elevation.
Marks and signage - refer to CSA B128.1 for directions
then on a sperate not connected page
CSA F379.1-8 allows the use of both single and double wall heat exchangers:
Drainback and Closed-loop SDHWS using a single wall heat exchanger
- require a non-toxic heat transfer fluid(inclusive of all additive) or potable water in the heat transfer loop at the time of installation. Material Safety Data Sheets (MSDS) for the specific product(s) being used may provide guidance for determining toxicity levels.
- require a heat exchange tube of stainless steel construction
- require the installation of a backflow preventer in accordance with CAN/CSA-B64.3, which is a dual check valve type, with atmospheric Port(DCAP) at the inlet to the solar hot water system
- require other safeguards such as a pressure gauge, pressure relief valve and maximum working pressure as specified in CAN/CSA-F379.1-88
Double wall heat exchanger
- require the use of a heat transfer fluid that is non-toxic, or toxic with a gosselin toxicity rating of 2 or less (inclusive of all additives)
- do not require use of a backflow preventer unless a make-up water connection is provided to the heat transfer loop
- require other safeguards such as a pressure gauge and a visible means of leak detection as specified in CAN/CSA-F379.1-88
BCBC requirements: The current BCBC does not require and additional safeguards for SDHWS beyond those required by the CSA standards, unless a make-up water connection is made directly to the solar heat transfer loop.
If a direct connect is made to provide make-up water to a solar heat transfer loop that contains anything other than potable water, this direct connection should be protected in accordance with Section 7.6.2 of the BCBC
the insector also pointed out that the backflow preventers need to be tested yearly.
So the big difference between this and the 1k system is the stainless heat exchanger requirement. The inspector suggested that the dual check valve back flow preventors are not going to be cheap plus the testing requirement and figured dual wall would be cheaper.
At this point I'm leaning towards a small 10-20 gallon stainless preheat tank with a stainless single wall coil built in it then pump the solar fluid through the coil. That is likely to be easier to get ok'd and cheaper then a giant stainless coil. It will require a second pump or a 3 way valve to turn off the connection to the panels and then just use the orignal pump. That seems finiky in my mind but be the better choice. Really the pc cooling pumps are only $70 so it's probably worth just spending the money on that.
Anyways at this point I'm looking for any advice on which way to go. I know I can order a stainless tank like this online but I can probably get one made locally and at least save the shipping. I'll have to look around and find pricing then ask the inspector.
Bottom line, - Don't accept no for an answer on this stuff. The city didn't do it's initial legwork and I almost walked away from the project because of it.
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