would rather have 5/8" plywood sheathing totally covered by waterproofing,

I suggest that such waterproofing is usually a 0 perm vapor barrier too. Vapor barrier on the exterior side in a cold climate - avoid it if you can.

The stack effect works to your advantage when using heat recovery ventilators in cold climates.

We licensed "yes licensed" mechanical contractors here in Minneapolis and use "Energy" recovery ventilators here and in our design practice around the country where cold weather usually means dry outside air. The ERV will recover latent heat going in both directions.

We prefer dedicated duct work and generally exhaust bathrooms and drop fresh air into bedrooms on any level. As with our high velocity air conditioning work terminal placement is a matter of proper design matched with positive experience and factory training.

I have a RenewAire EV 130 in my own remodeled home.

Bob:

First off, I meant to say "viewpoints", not "viewpints".

I will be installing the exterior vented range hood, and HRV bath vents are allowed here. I've been thinking of using blown cellulose; the only problem is how do I pack cellulose right up to the peak, with no voids? I guess the short answer is: hire an insulation contractor, and follow his directions. Alternately, I have a good supply of used 3" DOW SM, and, at R5/inch, 10" would give me the roofing insulation minimum of R50. I don't know, at this point, if less SM on the outside can be supplemented by Roxul, for instance, on the underside, but it will be great fun (not!) installing vapor barrier in the attic. My truss supplier is roughing out a sort of a modified scissor attic truss design, so that may make things easier all around. And yes, I will be installing a water barrier over the whole roof.

Jonr:

I mispoke: it's water drainage barrier over the plywood and under the steel roof, and vapor barrier under the roof.

Badger:

We will be using dedicated duct work with an HRV with ECM motors, timers in each bathroom, condensate drain, & electric resistance coils for defrost; the defrost was not a consideration until this miserable winter weather hit us where it hurts. To balance the system, all supply & return ducts will be of equal length, and the HRV itself will be sitting on the attic floor, or very nearly so. Our site is about 1/2 mile from Lake Ontario, so dry air should not be a problem, I hope. It has been written of multi-storey homes that "Dumping cold air on the upper storey of a multi storey home, can increase the thermal stack effect" and it will be "harder to balance the levels. Dumping it in a lower level and allowing it to work its way up slows down thermal stack." Our home is a bungalow with finished basement, so only 2 levels, but it did make me stop & think. I would be interested in how the stack effect will work to my advantage when using a heat recovery ventilator.

On the matter of dumping fresh air into the heating system return duct, the need for running the blower to move the air depends on the default setting of zone dampers when there is no call for heat or cooling. In my three-zone system, the dampers default to "open." When a zone calls for action, the dampers for the other two close.

Yes I agree that supply ducts in a master bedroom is really very cold and also too much of cold is uncomfortable. So, for the master bedroom I think, split window AC maintenance Manhattan will be very helpful. Still, I would say before installing take the advice of the HVAC contractors, they will suggest better.

You may duct fresh air in and out of a central HVAC system duct dedicated fresh air to the return of the central system while drawing air directly from sources of moisture such as bathrooms and kitchen.

In cold, dry climates such as high arid planes or mountains we will use a dedicated ERV controlling IAQ while radiating the floors for perfect comfort and healthy living.

Where the fresh air comes into the space depends on the architecture and the occupants along with air flow patterns.

Each house is unique so the designer must use experience and manufacturers' guidelines to come up with appropriate solutions.

Lbear:
Can you provide a source for the white poly flex duct shown in your picture posted 11 Jan 2015 please?
Thank You
Kirk.

The white poly flex duct is from Zehnder. http://zehnderamerica.com/

Very nice duct system--installers seem to like it a lot after they learn how to use it. Kind of expensive.

The duct itself has safety approvals in Europe but not the US; some building inspectors find that an issue.