An unusual (?) system - Does this system make sense to you?

Tomato

In the 1980s my company designed a system for a small residential building like a motel. (I was not involved in the design, and only learned about it later.) The long axis of the building was east and west which is important as you will see.

This was a new building and the system was supposed to save money, so the design was different from the normal installations at the time. The building was well insulated and made to comply with the new regulations which had resulted from the "oil crisis".

The idea behind the system was to capture heat from the south side during the day in the winter and move it to the north side, and to cool both sides during the summer.

Each housing unit was equipped with fan-coil-units that had little compressors, reversing valves, and Freon-water heat exchangers. The heat exchangers were connected to the single sprinkler (fire suppression) pipe which circulated water to each unit and to an equipment room. There was also a cooling tower, and I think, a boiler.

Now we would likely have some hydronic solar panels for the winter. I wonder if they could be used to radiate heat during the summer nights as well?

EdTheHeaterMan

Now you are using the fire suppression system as Hydronic piping?!? did I read this correctly? Did this pass inspection from both the Fire official and the Plumbing official? And if it did, does the system still work?

As far as using Hydronic Solar panels as heat emitters on summer nights, The idea might have some merit BUT ... heat collectors are enclosed to hold the heat IN... so they are not going to let the heat out very easily. You need to think about how the design will work and do the math.

If math is not in your wheelhouse then you need an engineering student from some college to do the math. I think they call them "Case Studies". Maybe you can write to your congressmen and get a grant. My tax dollars are there waiting for some politician to waste on a new useless study.

Respectfully submitted,
Mr.Ed

hot_rod

Yes solar flat panel panels can work in either direction. Some controllers actual have a night time heat dump or re-radiation function to cool down an over-heated tank. This is a common function used on empty or vacation homes that do not have a daily load. The control allows the tank to pull down to the lowest usable temperature, say 120F, so the next sunny day there can be some tank loading before the collectors go into stagnation.
A couple things about solar thermal heating, you get the most amount of output when you least need it, summertime. Its tough to pull a lot of energy from a cold winter sky as the ambient temperature around the collector steals a good %% of the solar gain.

Well insulated thermal storage becomes the holy grail.

Most all thermal collectors are rated by the SRCC, if you go to that website it will show you expected output under varying conditions and temperatures.
This journal explains how to put that data to actual use for calculating. Even in the sunny southwest heating areas, rarely do the get more than a 30% solar fraction.https://www.caleffi.com/sites/default/files/file/idronics_3_0920.pdf