You'd need to track down some options for materials, and think through accessibility (where in the ductwork can you install this thing, and get electrical to it. 

Unfortunately the coil is inside the ductwork and hard to see without taking stuff apart, but if you see ice or frost on the outside of the coil, or on the copper Freon lines at the furnace, that may be what's happening. 

We went with a forced air propane system and since there was electric baseboard heat in the unit prior there will need to be new ductwork installed also. 

As far as hvac, since you don't have the duct work, I'd expect it to be in a 5-digit price range. 

-Clean Dryer Exhaust Ductwork-Clean Refrigerator Coils-Clean Dishwasher-Clean Shower Heads-Inspect Sink & Toilet Fixtures for Leaks-Replace Air Filter-Re-Caulk Tub/Shower & Bathroom Floor-Flush Water Heater-Lubricate Garage Door Bearings-Replace Batteries in Thermostat & Smoke Detectors-Inspect slab for signs of termites; trench ground with Termidor every 5 years

I need to start putting the ductwork together.

Purchase price: $135,000 Cash invested: $50,000 Sale price: $293,000 This was not expected living flip in progress during first 4 years working full time job.What was done:- full kitchen remodel- replaced all plumbing- new duct work with insulation- relocate and redesign fireplace- full 1st bath remodel- add 2nd full luxury bath (double shower, bidet, radiant heat)- convert sun room to 4th bedroom with radiant heat flooring- replaced all windows- upscale woodwork inside- repaint whole house inside and outside First 4 years forced equity and another 4 years market bring us another surprise with icing on the cake (market going up).This year 2019 decided to cash out hard work and moved out from IL to another state TN.Planning to fully enter real estate game here in Knoxville/Maryville TN area.Currently looking for my primary residence here using cash out from IL.

Purchase price: $135,000 Cash invested: $50,000 Sale price: $293,000 Living flip working full time job-full kitchen remodel-replaced all plumbing-new duct work with insulation-relocate and redesign fireplace-full 1st bath remodel-add 2nd full luxury bath (double shower, bidet, radiant heat)-convert sun room to 4th bedroom with radiant heat flooring-replaced all windows-upscale woodwork inside-repaint whole house inside and outside First 4 years forced equity and another 4 years market bring us another surprise with icing on the cake (market going up).

Purchase price: $135,000 Cash invested: $50,000 Sale price: $293,000 Living flip working full time job-full kitchen remodel-replaced all plumbing-new duct work with insulation-relocate and redesign fireplace-full 1st bath remodel-add 2nd full luxury bath (double shower, bidet, radiant heat)-convert sun room to 4th bedroom with radiant heat flooring-replaced all windows-upscale woodwork inside-repaint whole house inside and outside First 4 years forced equity and another 4 years market bring us another surprise with icing on the cake (market going up) Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Purchase price: $135,000 Cash invested: $50,000 Sale price: $293,000Living flip working full time jobfull kitchen remodelreplaced all plumbingnew duct work with insulationrelocate and redesign fireplacefull 1st bath remodeladd 2nd full luxury bath (double shower, bidet, radiant heat)convert sun room to 4th bedroom with radiant heat flooringreplaced all windowsupscale woodwork insiderepaint whole house inside and outside First 4 years forced equity and another 4 years market bring us another surprise with icing on the cake (market going up)Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?