said by cowboyro:If I were to do it I'd put the 5-ton unit. Yes some will disagree, but if you have a variable speed blower the humidity issue will be taken care of.
You'd probably save more from being able to use setbacks than from being super-efficient and having all the savings wiped by just one very cold day. Not to mention that having a system blowing warm air is nice.
During a very cold day I use over 100kWh of electricity in addition to 7gal of oil.
My oil heat cost is $4/gal and 7 gal make 780k BTU, so 28000BTU/$ give or take.
Heat pump would give me 45000BTU/$ even with a lousy COP of 2
For the difference in cost of 1 day ($10 cheaper if I could produce the heat with the heat pump) I can run a dehumidifier for over 5 days (not that I would need, the system takes care of the humidity).
You have a fixation on the variable speed blower. I have a variable speed blower so what. Most all newer systems utilize that technology now. Your posts contradict all accepted HVAC design and operation.
At zero the other day My 3 ton with heat strips used 160 kWh. About $16. Removing the cost of the strips the 3 ton HP itself would be about 75 kWh or $7.50. There is no way 2 more tons (5 tons) would be enough at zero degrees.
Do your own math...