There is not really much mentioned about PTHP and very well insulated buildings. Every publication out there dealing with well insulated structures seems to be all mini split ductless or small duct high velocity hvac systems. Are PTHPs worth considering in place of the other just mentioned options? Below is a potential list of advantages and disadvantages that I came up with for considering a PTHP system, it seems to have some pretty good advantages. Why are we not seeing more of these in well insulated building projects, am I missing something, sans the larger whole in the wall I would think these units would work well where a mini split wall unit would go?
more reasonable pricing than ductless split systems
Usually offer inlet fresh air vent, that could be worked into a low cost fresh air vent with a exhaust vent wired into the fan thermostat circuit.
Ususally offer standard 24VAC thermostat control, perfect for smart home integration.
Reasonably efficient depending on which models selected with a range of 10-13 EER.
Usually has back up electrical resistance heat as a 2nd stage heat option for colder climates
Available in under 1 TON sizes as small as 7000 BTUs
Potential an issue since it will require a large about 43" x 16" hole to be placed in the wall, not sure if this would be a massive air / thermal transfer leak surface area even if a air tight seal is accomplished around the unit
Usually do not have a dedicated de-humidification / dry mode like many mini ductless systems do
Is not a efficient as mini ductless systems