I think 10-12 tons is probably going to be overkill if you intend to improve the building, but how would I know?
Seriously YOU need to take the measurements and run the math and come up with the total heat load number. I won't just keep taking WAGs at the size of windows & walls etc, since it's something that you should be able to measure up in under an hour. I've shown you the methodology- running an I=B=R type load calculation is 5th grade arithmetic, no rocket science required. All you need is the U-factors of the different stackups and the gross area, then it's:
U-factor x square feet x temperature difference= BTU/hr
Typical ducted air source heat pumps can deliver over 10,000 BTU/hr per ton @ +5F outdoor temps, but ductless systems will usually deliver over 13,000 BTU/hr per ton at +5F, but you still need to read the specs with the extended temperature capacity tables/charts to estimate the system capacity at any given temperature.
Those hollow concrete blocks are neither bricks nor cinder-blocks, but rather "concrete masonry units", (CMU). True cinder blocks using coal-cinder-aggregate/portland cement concrete haven't been commonly used in the US since the 1940s. Anything newer is usually a stone-aggregate concrete with better structural characteristics. The U-factor for 8" CMU wall with nothing but paint (no siding, no wallboard) is about 0.9 BTU/hr per degree-F per square foot. Any guess at a wall height is just a guess, but you can measure it subtract out the window & door area, and come up with a number.
Adding 2" of rigid EPS held in place by an overlay of 1x furring 24" o.c. through-screwed to the CMU onto which you hung half-inch wallboard would lower the U-factor of the wall to about U0.09, reducing wall losses by 90%, taking up about an inch less interior depth than a 2x4 studwall insulated with batts that performs about the same.
Aluminum-framed single-pane double hungs are about 1.1 BTU/hr per degree-F per square foot.(Not quite as good as wood-sashed windows due to the higher conductivity of the aluminum compared to wood.) You have 17 windows at about 7.8 square feet, for ~133 total square feet, so the window losses are about 1.1 x 133 x 70F= 1024 BTU/hr
Adding low-E storms would get you to about U0.37, reducing the window losses to 350 BTU/hr (about the heat emittance of one live human).
The roof is about U0.4, as previously assumed.
For the basement, run the numbers on only the portion of the wall that's above grade down to about a foot below grade.
Seriously YOU need to take the measurements and run the math and come up with the total heat load number. I won't just keep taking WAGs at the size of windows & walls etc, since it's something that you should be able to measure up in under an hour. I've shown you the methodology- running an I=B=R type load calculation is 5th grade arithmetic, no rocket science required. All you need is the U-factors of the different stackups and the gross area, then it's:
U-factor x square feet x temperature difference= BTU/hr
Typical ducted air source heat pumps can deliver over 10,000 BTU/hr per ton @ +5F outdoor temps, but ductless systems will usually deliver over 13,000 BTU/hr per ton at +5F, but you still need to read the specs with the extended temperature capacity tables/charts to estimate the system capacity at any given temperature.
Those hollow concrete blocks are neither bricks nor cinder-blocks, but rather "concrete masonry units", (CMU). True cinder blocks using coal-cinder-aggregate/portland cement concrete haven't been commonly used in the US since the 1940s. Anything newer is usually a stone-aggregate concrete with better structural characteristics. The U-factor for 8" CMU wall with nothing but paint (no siding, no wallboard) is about 0.9 BTU/hr per degree-F per square foot. Any guess at a wall height is just a guess, but you can measure it subtract out the window & door area, and come up with a number.
Adding 2" of rigid EPS held in place by an overlay of 1x furring 24" o.c. through-screwed to the CMU onto which you hung half-inch wallboard would lower the U-factor of the wall to about U0.09, reducing wall losses by 90%, taking up about an inch less interior depth than a 2x4 studwall insulated with batts that performs about the same.
Aluminum-framed single-pane double hungs are about 1.1 BTU/hr per degree-F per square foot.(Not quite as good as wood-sashed windows due to the higher conductivity of the aluminum compared to wood.) You have 17 windows at about 7.8 square feet, for ~133 total square feet, so the window losses are about 1.1 x 133 x 70F= 1024 BTU/hr
Adding low-E storms would get you to about U0.37, reducing the window losses to 350 BTU/hr (about the heat emittance of one live human).
The roof is about U0.4, as previously assumed.
For the basement, run the numbers on only the portion of the wall that's above grade down to about a foot below grade.