Should we have them put in supply,  exhaust  or both in the basement?  The HRV unit itself, and  ducting for upstairs will also be sitting in the basement, probably suspended from ceiling.  It's a 8 ft wall basement about 6.5 ft  underground. The HRV is standalone - not connected to a furnace or to the Panasonic bathroom exhaust fans.

We have R15 on the floor and walls - no wall covering for right now.  The Heat pump hot water heater should dehumidify so I don't expect it to be overly humid  but   I would due to the nature of it being a basement we'd want to get rid of some of the stale air in there.  I see this as being a play place for kids-   I'm thinking bare minimum an exhaust  but maybe both  on opposite sides of basement?

We currently have an even number of supplies and exhausts upstairs so might be easiest to keep that even for balancing?

Exhaust only in a basement.

It looks like he installed a small supply and exhaust. Is this OK? The issue I could think of with supply in the basement is that somehow it would push basement air upstairs.  I could have him block the supply and re-balance.
 

It depends on the basement and your climate. In humid weather an HRV will crank up the rH and cooling is easy in basements. One can and should always balance ventilation so the supply may be adjusted if need be.

IMO, every closed door space should have a supply and return. And be checked for any pressure imbalance with respect to the outside. I believe that adequate mixing will occur even without putting them on opposite sides of the room.

IMO, you may be right depending on the velocity of the system. I found few basement/first floors barriers to be air tight and even so most will have a loose door at the top of the stair, if any.

My only hesitation in running ventilation air to a wet climate basement is the unwanted moisture associated with it.

patonbike
verify that your blower door contractor can measure flow at the HRV outlets. And buy outlets/intakes* that can be opened or closed to change the flow; that way you can be sure that you have correct flows to & from every space, whether there are the same number of intakes/exhausts or not. *EFI.org carries the adjustable outlets - part #5540.01 for the 4".

patonbike
verify that your blower door contractor can measure flow at the HRV outlets. And buy outlets/intakes* that can be opened or closed to change the flow; that way you can be sure that you have correct flows to & from every space, whether there are the same number of intakes/exhausts or not. *EFI.org carries the adjustable outlets - part #5540.01 for the 4".

Ok thanks. It seems like we will be OK.

Technically we have a door on the basement but it's not sealed to the living area above.

We will have an heat pump HWH down there, so I hope it would stay pretty dry either way. I guess we can always remove the supply later if we find that it's getting too humid.

We do have the adjustable grills.
We used the new 80 gallon GE heat pump and the E15 ECM Venmar HRV.  Not running it yet because of all of the construction dust.