Heat Recovery Sizing for an Aquatic Center Air Handler

Max -

First things first.

17,000 CFM of outside ventilation air is sufficient to meet the IMC requirement for a 34,000 Square Foot pool and deck area.

Is your facility really this big? If not, your first order of business is to fix the massive energy drain caused by improper mechanical design of this system that is resulting in zero recirculation of air and 100% outside air.

A 100% Outside Air design is fine if desired, but then the supply air = OSA = Code requirement of 0.5 cfm/sf. No more, no less, and THEN you pretreat that 100% OSA by running it through a poly Heat Recovery core section (counter/cross flow) or place a coil in both the exhaust and the return air ducts to do the same.

If it is too late to reconfigure this to stop this massive waste of energy, and you are just doing retro- work, I would still recommend putting a VFD on the supply fan.

Once you have your airflows corrected, then have a discussion with a refrigerant-based coil supplier engineering rep.
You may well have a great opportunity here to do energy recovery with a lower pressure drop by using a mechanical refrigerant system to vapor/condense more efficiently than a "pumped" system, by which I presume you mean hydronic:water+antifreeze.

A refrigerant heat recovery 2-coil system would be sized by the supplier for you based on the physical size of your exhaust/return duct with the airflows involved. You may or may not need to place a compressor, accumulator, TXV, etc. inline as a powered mechanical system, since it is possible, depending on the temperatures involved, that you may get away with a passive evaporation-based system if this is a unitary packaged equipment installation.

Thank you for the wake-up. I must have had a brain block. I'll get started on the air flow correction right away. Thank you again