Hello All I have just recently signed up to GBT and love all of the insite and information I have gotten so far. I am planning on building a 30x 54 single story SIP home on a radiant heated slab foundation in NH. The house will have truss roof system, triple pane windows,wall hung instant propane fired hot water heater and low voc paints and finishes.I would like to eventually install solar hot water so I will be planning on running the provisions for that. I have been reading up on how tight SIP homes are and need HRV's or Erv's. I guess the question I have is...Are they critical to have in every room/ bed room? or can I get away with just installing a simple one for the whole floor in a central location? Also looking for some layouts or diagrams on best practices for the install and running the duct work and such. The house is a simple rectangle split down the center with bedrooms and bathrooms on one side and living and kitchen on the other.I have done my best to design the house with some cross ventilation using east and west windows. Any input would be greatly appreciated.

In general, you want to supply air into the bedrooms and maybe a main living space (particularly a media room or where people gather) and exhaust air from bathrooms, kitchen, laundry room, etc. However, code can dictate. Hope that fits with your cross-ventilation plan.

Try to have a minimum amount of ducting and use smooth ducting. Typical units have 6" connections, but you will want to use 8" for the main trunks.
Try to design an access chase so that ducting is in conditioned space. Less insulation that way.

Try not to position a supply register where it will blow air on anyone. It tends to be cooler air.

I added a hot water coil to the supply ducting in an attempt to relieve that issue. I'm going to supply the coil from my radiant heating system, but I may end up supplying it from domestic hot water.

In NH, you might want to investigate the need to preheat the incoming air during extremely cold periods as well.

As an option, a house that size can be easily heated with an electric minisplit air conditioners running on a couple of grid tied PV panels. Or, if you do radiant, you could use extra solar thermal panels. (Check out RadiantTec in Vt) Make sure your slab is completely thermally decoupled from the ground and foundation, and that the R value of your SIPS (and floor, and roof) is sufficient. The biggest issue with wall SIPS is thermal bridging so pay attention to that. Strap the exterior of the walls ("rainscreen") so that any water penetrations don't affect the integrity of the panels. I assume you are using raised heel trusses to get the necessary R values.(?) You can use one HRV ducted to the outlets with 4" "sewer & drain" PVC pipe ( use the solid type you can glue together - hard to find but available in our area.) Simple straight layout is best with the unit in a central (heated!!!) location. You can put the unit in a closet & run the ducts in the "attic" in a small conditioned space you'll build under the insulation.

Thanks for the input guys. I just talked to the local inspector and was told that the frost protected shallow foundation i was planning on building with is not going to fly in my town. Kind of a bummer because the alternative is 4ft frost wall slab on grade which costs a bit more... I may have to re think my floor plan to get a smaller foot print. I will most likely do a slab on grade with attic trusses and sip walls. Kind of curious what the return on investment would be form a r28 wall compared to an r 38 wall...I am way off topic for this post, I know...Bob I see you are a Passive house consultant. I am very interested in your opinon on this... I am on a very tight budget to build a house so I can start a family and so on. I am interested in building an energy efficient home that will be comfortable and inexpensive to heat/ maintain. Are there any " stock" house plans that include a heat loss/ gain calc so I could kind of get an idea of what to expect or any services that can look over my plans and let me know what the expect for heating and cooling??

Gusto421: Since you asked - the least expensive way to build that house will be double (2x4) stud walls with 10" - 12" of dense pack cellulose (R35-R42), and raised heel trusses. Any HERS rater as well as some builders can do computer simulations of the house to estimate heat loss. (I use REM design.) I'm in central NH; write to me if I can help.
Bob

Thanks Bob I will be contacting you soon!