The high volume air flow thru the heat pump condenser and evaporator is just the normal way those units work...reduce the air flow characteristics and your unit by putting it in a shed, or plumbing ductwork to it...could become less efficient at cooling the house. I would rather improve ventilating the attic with turbines, additional soffet vents, or perhaps a separate exhaust fan for the attic only, than sending/plumbing cold air conditioning to cool the attic.
You might try dehydrating food,
roots, leaves, perhaps even
firewood using the excessive air flow from the outdoor unit...just don't degrade the air flow thru the heat pump unit. For example: if your firewood was air stacked (for high air flow) and some sort of pole barn were surrounding the firewood (to keep the rain off of it & somewhat direct the excess heat pump air thru the firewood), you might be able to air dry said firewood even during the rainy season...could become a potential fire hazard if located closer than 50' to the house.
Same example for food, roots, leaves, various wire racks within a shed (heat pump within the shed) and blow all the moisture off of those items, especially on rainy days it
should work better than normal air drying. You would just have to be careful about the actual temperature of food...generally 110F is about the max. for drying roots & bark, higher temps will discolor the product. Sometimes when I collect fresh produce, the normal weather (excessive rain like this year) is just too damp to air dry for 3-5 days...if I had a heat pump, I could see how that could dry the produce much faster, maybe before it rains again.
This is just a funny suggestion...I've never tried it.
james beam