Yeah, central vac is not going to do what you need for heating/cooling unless you want your HVAC to sound like a server room/leaf blower. There's a reason ducting is normally big in houses -- its so the air can move slowly (quiet and power-efficient) but because of the large cross section, you can still move a lot of air.
There's an additional problem where it all joins up to the vac in that, the vac is only designed to achieve that level of suck at a single vent and isn't likely going to a wider pipe as multiple vents join to the vac tubing. Open multiple and turn it on and you'll probably quickly discover you have no real air motion anywhere.
I was not describing it well. The Central Vac was put in long after the house was built. It is in the centre of the house. With a line to the main floor and a separate one to the top floor.
I want to remove all the plastic vacuum stuff. And make the holes in the floor and walls slightly bigger. Basically using them as metal ducts. Except it would just be ducts open to the basement and other floors. Using metal duct work like you do for moving air from furnaces.
But it would not have much air movement without a fan inside the duct work.
I want to ise it to exchange air. Remove all the vacuum parts. Is there a point though? How much air will get moved? It would not cost a lot of material to do it.
The whole using water was probably not a needed part of the question, just longer term, solar panels and a cistern and using water is just a dream.
But every time I see the central vac or the lines... I keep thinking that this no longer used central vac lines through an older house could be useful, as a right of way to move air... or later water.
I did ask the question in a weird open ended way, because perhaps there is a better way to use the space and holes already created. And maybe someone here has done it or heard of a way to do ot, I have not thought of yet.
