Where to begin?

We are planning to build a passive solar cabin/house using SIPs in northern Minnesota. Pretty small, about 900 sq ft (24'x40'), single level, shed style roof with 8' walls on one end and 12' or so walls on the other. 2 small bedrooms, big living/kitchen area, simple shower/toilet and mud room. Completely off grid.

Weekend retreat for now and eventually we'd like to move there. Camping and using an outhouse is only so much fun and we can't improve the property without a better structure and shelter for tools etc. For now we "just" want to put up the house with siding/roof/interior walls and a composting toilet etc. Then we will be able to finish off the bathroom/kitchen etc. and we will be able to improve the property overall. We will provision the house for water and waste hook up but for now we won't hook up a well nor hook up to a drain field due to cost. We may get a well for some water but we were told that hooking it up to the house triggers some county requirements.

We had some ideas of what we wanted and a contact at one of the SIP manufacturers put us in touch with a design/drafter guy they use a for a lot of their customer's designs who put our sketches and ideas to proper paper.

The SIP manufacturer said they would do the math using the design to show it was passive solar and tell us if we needed to adjust the window sizes up/down and the thickness of the concrete slab etc. Well..... what we got was some standard report which showed how much energy we were used and saved etc. Unfortunately nothing about passive solar stuff. We contacted a passive house designer/licensed architect to contract with them to do the proper math and assist with ensuring the right design/SIP/passive solar/window types/ventilation etc. etc. is achieved. Learn from my mistake is assuming the sales guy knew what I wanted and I understood what he was meaning when he spoke.

Here is the hurdle we have to clear. The PH designer/architect said they had never seen a SIP passive solar house off grid and that the problem is to ensure we meet the correct volume of fresh air circulation thru the building. They were nice enough to let us know they did not want to take on the project if they would not be able to truly be effective. Pretty cool and honest of them!
In my mind I wanted to "just" hook up some sort fan on one end of the house to a small solar panel to have it suck air thru some sort of opening on the other end of the house. Yes, I am simplifying the system but you get the idea. I was hoping the architect would be able to help with these system's details but that won't work.

We don't have much time before the 2016 construction season is over with and we would like to have it build before the fall. It would be really great if anyone here could provide some leads or solutions as to how we could go about this system.

Some questions:
Anyone ever hear of an off grid passive solar SIP house?
Anyone know a good size fan-system we could install?
What volume do we need to move (designer did not want to speculate unfortunately)?
Any other hints and tips which could help us button this up?

With this data I hope to do some research to electrical power requirement to search out the solar panel and probably battery system. The tricky part also of course is the PV system and the fact we aren't going to be there every weekend (we are about 2 hours away). I could ask the one neighbor who lives down the road year round if he could check the PV system every week or so and let me know if something is out of wack. He's also off grid with a big PV system so a lot of knowledge there and I have no proble giving him some cash for his time and knowledge.

Any hints, tips, advice, criticism, links, key words will be greatly appreciated.

A question I have is why does the Passive House designer not know what to do with SIPs? Is it the construction method that they aren't familiar with, or is it that they have never designed off-grid?

Of course they know SIPs, they just never had an off grid SIPs house. This makes the mechanical ventilation system something new to them

To me the off-grid passive solar SIPs house must be something which was done before we came along so there must be someone with experience out there.

Ok then can we deduce that they've never designed *any* off-grid mechanical ventilation system? What I'm trying to get at is the SIPs part of it is really beside the point isn't it. Surely they are familiar with mechanical ventilation.

Yep, apparently no one ever asked them for an off-grid mechanical ventilation system....

SIPs are kinda part of it though. In MN if it is an airtight structure like a SIP house you must provide a mechanical vent system, at least that is what I have been told by them. Had we planned to build a traditional leaky house it would not be that much of an issue I guess.

I am starting to wonder if I should find other engineers.

Take a look at the Panasonic FV-04VE1 HRV. No need to run it when you aren't there.

I would build the entire place so that it can, after some pipe blowing, safely freeze.

First, lets not confuse active photovoltaic (PV) power with passive solar heating. Here’s an excerpt from our website:

“Your building's roof, windows, walls, and floors can be designed to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. This is called passive solar heating or climatic solar heating and this is really the first step toward environmentally friendly construction and reducing your utility expenses. Passive solar heating can provide between 30 to 98% of your annual heating needs depending on your building's available south window area, construction materials/methods, location (i.e., latitude, orientation, and climate), and the overall integrated heating system design approach. A hydronic radiant floor heating system design that is fully integrated with the passive solar heating design is typically required to provide passive solar heating which exceeds about 50% of a building's annual heating needs in order to provide the necessary heat storage/rejection capability to address periods without sun and to ensure never overheating the building.”

Here’s an example of a professional passive solar heating analysis:

Borst Sample Passive Solar Analysis

Here’s a suite of free passive solar heating design software to accomplish a DIY passive solar analysis:

Borst Passive Solar Altitude Angle Software

Borst Passive Solar Roof Overhang Design Software

Borst Passive Solar Fenestration Exposure Software

Borst Passive Solar Heat Gain Software

Borst Passive Solar Thermal Mass Performance Software

SIPs is just one method of constructing a building envelope. 2x4/6 and ICF would be other methods and their only relationship with passive solar heating is their effect on the building effective insulation R value and on the building air infiltration rate (i.e., the building heat loss analysis results) which needs to be accomplished in conjunction with the passive solar heating analysis to enable proper sizing the solar fenestration (i.e., doors/windows on south wall), and proper sizing of the thermal mass. You don’t need to significantly move air around in a successful passive solar building design. A standard HRV system is all that is recommended and needed.

And Happy Summer Solstice and Honey Moon to all!

Posted By sailawayrb on 21 Jun 2016 05:26 PM
...

And Happy Summer Solstice and Honey Moon to all! ...

Wait, I thought it was a strawberry moon!?

Yes, in the States it is more commonly known as a Strawberry Moon. In Europe it is more commonly known as a Honey Moon...because of the golden-orange hue given off by this low-suspended moon. It is also sometimes called a Hot Moon, Long Night Moon, Rose Moon or Mead Moon. The last time it occurred was 1967 and it won’t occur again until 2062...so a somewhat rare event.

Strawberry Moon

I built an on-grid SIP cabin last year nearly the same size as yours and have been living in it since December. One thing I did was to align the door and kitchen window to the southwest (the prevailing direction of winds up here on a ridge) so that wind would come through the cabin and exit out through the back porch door. Being on top of a ridge we do experience some good winds quite often but at least by our needs, it works quite well.

I also installed three HotSpot hybrid mini-splits (http://www.hotspotenergy.com/solar-air-conditioner/) and couldn't be happier. I do plan to hook panels up to them next year and get most of our day heating and cooling out of solar.