Solar Shop Heating
I would like to begin a discussion on Solar shop heating. My situation is this. I have built a new shop(34′ x 14′) and I was able to orient it so I have the long section of the roof facing directly south. Since the site was in the shade during the leafy months and in sun for most of the day during the winter, I began thinking and reading about what it would take to capitalize on the solar gain during the cold months(in NC, probably Dec. thru March). I have taken the first steps of insulating the slab(2″extruded foam) and placing pex in the floor before the pour. These first steps were quite reasonable price wise and required only minimal extra labor. I am now at the point where I am looking at the big ticket items such as vacuum tube solar collectors , sensor systems, valve controllers and pumps to complete the system. Perhaps I should take the long view that I am going to save money over the years on heating costs, but something rubs me about these vaulted expenses and I’m curious what my illustrious “brothers of the blade” have to say. Is there a way to SIMPLY get the heat from the sun into my floor and to safeguard against overheating? My thoughts have led me to building insulated doors that would cover the tubes when not needed and a simple timer placed on the pump to circulate the water during daylight hours. Please give me your thoughts, or experiences you’ve had trying to solar heat a shop.
Many thanks for reading this
Well, the simplest desing would be to just run a radiant floor system to te collector panels an just use 50/50 water/antifreeze. That would be "throttled" with a pump & thermostat of some sort. Using 'standard' WH panels would likely work, too (or would be "simple" at least, as off-the-shelf technology).
That would be simple. Simple does not always work. It might be that having a storage tank/mass would make sense--it might not, too. If you use a storage tank will invite water heating, which gets you out of the single heating fluid simplicity (to prevent DHW contamination).
Now, RFH has some advantages, one is that really high water temps are not always needed. In a shop situation, where we presume clothed and shod use, "we" get a bit more leeway for temps, too.
Now, one thing that does occur though, is that in a shop situation, I'd be very inclined to painting or otherwise permantly making the location of the heating tubes i nthe finished slab--all the better to not put a bolt into the slabe through a tube i nthe future.