Awesome, did more digging and it turns out it’s an HRV and likely not something I need to be running during the summer months as I don’t need more warm air circulating and we keep windows open often enough to naturally exchange the air.

Unfortunately with the house layout there isn’t a good spot to put a fan at the top of the stairs as it will block the narrow hallway that exists between the bedrooms as well can’t put it on the stairs because they are spiral.

Yeah not the most handy person and electrical freaks me out so expecting the higher cost of having a professional do it but luckily where i live (Canada) there are federal programs that offer rebates on things like this if the options we choose are eco friendly so, might be expensive but we should get money back providing we follow the regulations.

Yeah I think the split isn’t enough for the house, not sure how they withstood the humid temperatures through the summer, especially the kids rooms. Can’t see how many BTU’s the current system is but probably going to need to upgrade that unit and add more wall units. Unsure what to do about the kids rooms at night though with there doors closed there is no way the cold air will get in and a fan will only push the hot air around. We have a portable AC that looks like a mini-fridge, but my concern is leaving that in room with the toddler as I want to avoid an accident of it falling onto her.

Ah good point, I didn’t think of the consequences of mixing the different air temperatures through the ducts. Ideally I would like to avoid blowing mold all throughout my children’s bedrooms.