HVAC reclaim coil liquid contents

Doing some demolition at a College Campus and came across a heat recovery, reclaim coil that is approximately 4 feet high and eight feet long.
The unit coil is mounted on a pair of pillar box bearings and pivots back and forth like a see-saw in operation.
It is full of a liquid that no one knows.
We are trying to find more information on this system that was installed in 1984, before we dispose of it. We are trying to identify the liquid substances inside that might be hazardous.

It was Manufactured by what I hear Q. or Qdot manufactures that is possibly no longer in business. That is the only lead we have.

Our next resort is to contact a Company known as Clean Harbors that specializes in envioronmental clean-ups.
Identifying the liquid inside would be a tremendous help.

If any HVAC people out there have a clue, it would be appreciated.

There are alot of older Mechanics in the trades out there, and no one has ever seen anything like it. The College has no records of it either.

Help would be appreciated.

Thanks in advance.