We have a very small property in Wellington which our asthmatic daughter, her partner and our wee baby grandson rent from us. It's tiny at 60m2 all up with an open plan lounge and kitchen, with the bathroom and both bedrooms off the lounge. It is the end unit of a set of concrete block units, and has ceiling insulation.
They currently have a wall mounted heat pump which we have been told at 3.2kw is far too small to heat the home.
We really need to put a ventilation system in to help with condensation and our daughter's asthma and the fact that there is a baby in the house who has been very congested over winter. We've read a lot of forums on here regarding various ventilation systems and it seems we'd need to get something a little more expensive than the basic HRV type, so we can have a proper heat recovery unit.
* (The forum posters here sure are right re HRV, they tried to tell us their system could on a good day increase the home temperature by up to 5 degrees! )
So we're looking for some advice as to how we should go about this. We don't want to spend heaps of $ on a system that we won't be able to recover on selling it when the 'kids' move on in a few years.
Can someone please advise on the following:
* Would a heat transfer unit help by moving heat from the closed off lounge/kitchen to the bedrooms, even though the heat pump is too small for the whole house? Perhaps a heat recovery/exchanger unit within a ventilation system help with this?
* Would anyone know if it might be worthwhile (economically) to move the small heat pump to the baby's room then put a (new) larger system in the main area?
* Has anyone heard of opportunities to purchase ex-showroom models of heat pumps at a good price?
* Are there any systems which will both heat the house and ventilate (albeit at different times of the day)? I understand some of the wall units do this but of course they don't offer the heat exchange properties.
We've done a lot of research and it's all rather confusing as to what would be our best options, so would really appreciate advice.
Many thanks :-)