Design help sought

[Gone_Fishin]

Hi this is my first posting, 

My wife and I are trying to design an earth sheltered house for off-grid use.  We are looking to buy a site  & build in NW Ontario on a lakeshore.  The winters are even colder there than here in MN (I've heard as low as -60' F at times!!!)  My question is about plumbing.

The hurdle for me is how do we provide ourselves a bathtub with hot water?  My dear has had several back surgeries and really enjoys a daily soak--we think the back problem is solved and will not bother her much again...   Is there an energy efficient way to deal with this?  Indoor hot tub, and sitz baths and wash your hair the sink (actually I don't have much hair left at my age).  Or an outdoor heavily-insulated wood-fired hot tub?  Or indoor bathtub / conventional-like, with water filled and dumped daily?  Can we pull lakewater up daily using a solar RV type pump through heated lines or will they freeze in that kind of temp?  Would we have to create a massive (indoor) reservoir?  Wouldn't an outdoor reservoir of water on stilts just freeze solid?  The amount of space an indoor reservoir would take seems ludicrous.

Any advice would be appreciated

John

[considerations]

Maybe an insulated propane source and an on-demand water heater?

On demand water heaters don't require a water tank and since they heat the water as it passes through them.  They also do not take up any space to speak of.

They are a better deal per BTU if run on propane instead of electric. 

When propane gets cold enough, the pressure in the tank goes down. 

So, you would have to figure out that part.

As for water at 60 below, whew.....I have never had to deal with that.

[ScottA]

How do you plan to heat the house? Lets start there.

[glenn kangiser]

...also - off grid - how much power will you have available --

Wood heat?

Lot of water for a hot tub if dumped daily plus a lt of wasted heat. I would think maybe semi-permanent water - saltwater with a saltwater chlorinator to save on chemicals - it doesn't use a lot of power and is cheap - the chorinator is about $129 at Costco.About 120 watts for a hour or two per day probably. 

Will you have enough solar for this kind of stuff?  Hydro is out if rivers are frozen - Wind power?  Generator backup.  It gets expensive.

[Gone_Fishin]

How to stay warm (and clean)...

The general plan is to use an indoor wood stove to heat, with a propane backup wall heater, propane refrigerator and stove, and have a gasoline generator available if solar isn't enough to power the toys...  How big a generator...I haven't done any calc's yet.  We'd like to find a south facing site and shelter the structure with a meter of earth on 3 sides and the top.

I know folks in MN and WI will use heated coils around/in their water lines for drawing lake water in the winter, but I don't know if that would work in Ontario.  And how much energy that would use--I have no idea? 

Hot water on demand sounds like a good idea.  That's propane fired isn't it?  A little trickle sort of shower would be finefor cleanup; for her back maybe a very small covered & insulated hot tub.  I know lots of people like saunas, but somehow neither of us take to them--they seem to burn out our respiratory tracts and then we get colds. 

John

[ScottA]

I'd suggest a submersable pump in the lake rigged to drain back when the pump shuts off. You'll need an indoor water storage tank maybe in the attic. You'll need to run the pump off the generator when the water gets low in the tank. You could heat water on the wood stove and pour it into the tub. If you want standard plumbing you'll need heat trace cables and insulation on your  water lines outside and since your line will be going to the lake I'd say steam trace would be your best best. We had to do this on some houses we built in colorado up on the contenintal divide due to permafrost over 7' down. For that you'll need a boiler. If you go that route you could build a wood fired boiler and use it to heat the house as well.

[Gone_Fishin]

Thanks Scott,

Good ideas, I will make notes of this.

John

[akdreamin]

Wood fired boilers have become very popular here in Fairbanks.  I have helped a couple of friends install them.  It would allow you to have a standard hot water storage used with oil or natural gas fired boiler.  They are heavy, so if you are building off the road system, logistics could be a problem.  A friend had one flown to his cabin on a twin otter.  This is the brand I am most familiar with:  http://www.centralboiler.com/home.html