VanEE exchanger duct install

[Tailee]

I am replacing an old VanEE 90 H model 1601606 with  NEW  VanEE V160H75RS HRV
Want to make the connections right.
There are two ducts headed outside - connect them to 2 and 4 on the diagram.

One duct was a 4' duct headed to the cold air return and it is sucking air.
The other duct disappears into the ceiling and I can't tell if it is hot/cold and cannot tell if it is blowing or sucking.

Where would I hook up 1 and 3?

[Admin]

What ports were the indoor ducts connected to on the old HRV?  They should be labelled Fresh Air to Building and Stale Air from Building.  You should connect them to the same ports on the new HRV.

Is this a dedicated installation with vents in the bathrooms using separate timers?

In the V160H75 manual Vanee specifies a T1, T2, T3, T4 and T5 installation, but in Ontario our building Code does not allow HRV connections to the supply duct so we can't use T3 or T5.  If you don't have vents or timers in the bathrooms you are likely using a T4 installation.  Both indoor HRV ducts should be connected to the return air.  I posted the manual for reference.  See page 7.

The indoor HRV duct installed closest to the furnace should be the Fresh Air to Building, Port 3.  Likely the other HRV indoor duct is installed in the return duct at least 3' from the other HRV indoor duct.  It would be the Stale Air from Building, Port 1.  When you disconnect it from the HRV it should also be sucking when the furnace fan is running.  It's hard to say if it's actually connected without seeing it.  Framers sometimes pinch the duct when they are finishing the basement.  It wouldn't be sucking as hard as the duct closest to the furnace.  Especially if you have the other duct disconnected from the HRV.

Keep in mind, if you are using a control upstairs the new Vanee HRV and control will require 4 wires.  The 90H control only used 3 wires.  A T4 installation also requires that you interlock (synchronize) the HRV with the furnace fan, so that the furnace fan runs anytime the HRV starts.

[Tailee]

Thank you. The old one is 2005 and thanks for the great info on Ontario code.
The old one had was using only the green and black wire to the controller of the 4 wires. I am replacing it with vanEE Advanced Touchscreen Control Part No. 41303 to my Armstrong Utra V Model G1D91BU100D16C-1A which is on a Nest. There is also a Venmar Hepa 3.2 connected. Should this also be synced to the furnace fan?

[Admin]

Yes, you can use 4 wires to interlock the furnace, or 6 wires if you want to synchronize the heating and cooling.  This will make it more efficient.

The Virtuo technology allows synchronizing the unit operation with the furnace/AHU operating time. It prevents unnecessary AHU operating time while providing a better air distribution.