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So I have a job that I am installing heat and a/c via an Acadia heat pump.
So today, I get called in by the owner and wants to know how the solar system works with a Rinnai. I did not install the solar system. But it did make me question a few things and now I need help with answers.
The solar company has a 16 array of Sundra tubes on the roof, (2) 40 gallon electric water heaters, a flat plate heat exchanger, and 30 feet of baseboard in the crawl space as a dump zone. The home is energy star rated, so it is extremely tight, has the concrete in the crawl space completely encapsulated with 4" of foam and spray foam in the sill plates. The crawl space floor is dirt. This system is piped through a Rinnai tankless water heater. The house will be empty more than not.It is a british rental house.
My questions are:
A) I say that the dump zone baseboard will affect my cooling loads. The solar guys say that it wont, they say the earth will absorb the energy produced from the dump zone. That dump zone will be working all of the time as the tanks will heat up and remain unused.
B) The solar guys claim that the Rinnai will work seamless in conjunction with the solar system. I believe that there are going to be short cycling issues with the Rinnai. I believe that because if the solar can only heat the tanks to 110 and the Rinnai is set at 125 degrees, when the water flows through the Rinnai and turns it on, it will heat up to 125 too quick and shut down. This will cause water temp fluctuations. I say that there needs to be a buffer on the outlet of the heater.
So please help me. I will be talking with the solar guys next week.