Water and space heating

[mbeland]

A lady friend of mine has this nice tourism project of building a vacation resort around a small private lake (beautiful site)in Northern New Brunswick. She would like to build approx 5 cabins and is interested to base the concept on renewable energy. She won't do the work herself and she wants to have the cabins site assembled from prefab parts.

The cabins will be small 1 or 2 bedrooms on concrete post foundation with full service inside each (washroom and kitchen) and will sit close to the lake and surrounded by trees except for a few removed for the view on the lake.

A central laundry shed will be available for users and will be more exposed to sunlight (further away from trees).

I advised her to :

1. - design for passive solar and superinsulation of the cabins
   
2. - find yourself a very collaborative plumber and knowledgeable handyman
   
3. - build the south wall of the laundry shed of solar water collectors like Gary's from www.builditsolar.com, with a large drain back heat storage tank underneath the floor.
   
4. - have a radiant heat floor loop installed in the cabins
   
5. - plan for space heating (just to keep them from freezing) when the cabins are not in use and water heating when in use + small wood stove when cabin in use
   
6. - dig trenches to bring water to the cabins (4 water pipes: 2 for space heating and 2 for cold and hot water lines, 1 sewer pipe)
   
7. - install pumps to pump the sewer up away from the lake to the sceptic tank.
   
7. - bring the grid in and keep the wind mill grid tie for later project
   
8. - forget pv
   
   

She suggested insulating the floors of the cabins with urethane foam to keep the critters out. I told her that could oblige her to put the radiant floor loop above and pour a light slab with tiles on top. That could make for an easy to maintain floor surface and safe for wood stove use.

I think the hardest part will be to find a plumber collaborative enough to do to the plumbing

What do you think of my suggestions?

Am I shooting to high for this lady who is new to all this.

Thanks for your help,

Martin

[ghurd]

Places I go in northern Quebec leave the pipes exposed or only 2" deep.  I was told they WILL freeze no matter what, and they make it easy to replace.  They are drained at the end of season, but some still manage to break every year.

G-

[Airstream]

Also, whether or not the pipes & contents 'freeze' is not the whole story - its the ground freeze & thaw cycle movements that eventually grind rocks and such into the wires/pipes and those shearing forces will always win over time unless there is wide trenches and fine gravel bedding...

If this is to be a commercial enterprise before one shovel of soil is moved or tree is cut get a professional site survey(s) done by RE specialists with good track records!!! The small monies spent up front can make ALL the difference by putting their reputation and real world practical knowledge to use (or keep friends and family on speaking terms later on when 'things' overlooked turn into 'monsters')...

[mbeland]

The thing is supposed to be used year round. I guess trenches will have to be dug deep enough to avoid freezing. At my house the pipe from the well to the house runs 7 feet deep with no problem. I guess the tricky part will be the part that will run from the ground up to the cabin floor. It could have a pipe heater.

Martin

[mbeland]

Very wise suggestions to get an RE company to do a site survey. I guess it would be more realistic that way. I advised as if I did it for myself and don't have time to get involve in the work. When I get time, I will do a system at my place first.

I don't know any such entrepreneurs in the area though. Do any of you know?

Martin

[ghurd]

Could run the vertical pipes inside 4" (6"?) PVC full of insulation.

From deep in the ground to the floor.

I did it at a problem place and it worked great.  Not nearly as cold around here as NB.

G-

[GaryGary]

Hi,

I suppose the passive solar may be difficult if the cabins are in the trees.  Its pretty easy to do the solar site survey yourself with this:

http://www.builditsolar.com/SiteSurvey/site_survey.htm

and find out for sure.

The super insulation and small cabin size should keep the heating demand pretty low.  

Why not put a wood burner in each cabin and heat with that?  Zero net carbon, and it seems like people using a cabin might like the idea of a wood burner?

If it was done carefully, you might heat water with a coil in the wood burner -- this has some steam explosion safety hazards, so the plumbing needs to be done with care.

On the sewage side.

Maybe consider composting toilets?  Again, this might be something people renting cabins might like to try?  No septic tank or septic tank pollution issues.

Some of them don't work well, so its important to do your homework.

We stayed in one set of cabins up at Lake O'Hara in Alberta that had actually installed an air (vacuum) toilet system.  They have a trunk line that runs past each cabin.  The lines are mostly above ground, and I suppose that with this type of toilet, there is no danger of freezing.  The system seemed to work quite well -- gives a very satisfying whooosh every time you flush.  Not sure what the power or cost implications are.

The solar water heating on the central laundry should work well, and a regular carpenter and plumber should be able to build a bigger version of the $1K type system with no problems -- its all very straightforward carpentry and plumbing.

Gary

[SteveCH]

Let me inject here a comment re: compost toilets. Since we have one and have had it since around 1985, I advise people who want to know that compost toilets in cool climes are simply not great. The composting process needs warmth to keep the bacteria and other agents working efficiently; in fact, in cool temp's one cannot tell they are working at all. In a higher-use, commercial situation, it will be a constant source of hassle. Basically, they'll have to be emptied out frequently and it ain't pleasant and you are faced with what to do with the material that was cleaned out....

I suppose it would be possible to keep the toilet chamber heated somehow, as with some of that hot water, but, again, in a commercial situation there will be, trust me, some unhappy "campers." And, the heating system to do so would, in my opinion, add another level of technology, upkeep, and hassle to the system.

There are Incinolets, the electric toilets that burn the stuff, and the propane ones, likewise. Of course, you would need more electricity or propane to do that. I looked into both; the electric ones use far more electricity than one would want to provide with PV or wind [except at the exact time the wind was blowing sufficiently], and there was no way I was gonna buy propane or any other such fuel to run my toilet. If I recall [and it was some years ago that I looked into this], the co. selling propane-fired toilets suggested that for a 2-person cabin, one could probably expect about 30 gal. per month propane useage. I have no experience to tell me whether that is accurate.

Not trying to be discouraging or anything, just realistic.....

[ghurd]

Two things I have witnessed many times with touristy types...

People who like composting toilets are not the type who rent a cabin.

I will sleep in mud and eat things contaminated with whatever, but I don't care for peeing in composting poo, and the splash effect is a phobia.  "Junior" can even get stage fright.

We use the term "Going out to check the propane tanks", which is not completely gender based if you know what I mean... nuf said about that.

Little tiny cabins with wood burners.  People do 100% love it, but the temp choice is an oven or a fridge.  Burning a small pile of kindling is often too much heat at once.  When it goes out, the temp is too low again.

Might be perfect for some kind of small heat reservoir near the stove?

G-

[mbeland]

Thanks Gary for the optimism always found in your postings and for the input on the site survey.

Burning wood would be fine for when people use the cabin but if or when the cabin is not used, the owner will not want to have to feed the stoves. I thought that solar could be used for water heating when cabin is used (complementing space heating with the wood stoves) and for space heating when cabin not in use (and no water usage). This way the overall heat demand would be lower.

I don't think my friend would like to take the risk about the steam explosion safety hazards inherent with heating water with wood stove. Things need to be simple to implement and maintain, reliable.

Even if she could find good composting toilets (which is a hard one), she still would need to manage shower, kitchen and laundry water.

If the solar water heating is envisioned, the hard part for me is the sizing of the collectors, storage tanks, heat exchangers, etc. I suppose we could size it basically for domestic water heating and the space heating would be just baseline heating. Do I just multiply Gary's numbers by roughly 5 assuming the equivalent of one family per cabin (if the site survey shows few obstacles to sun path on the shed)? Half of the trees are deciduous.

 Thanks again,

Martin

[mbeland]

What do you mean by some kind of small heat reservoir near the stove? Do you mean a "poele de masse" or masonry close to the stove to limit temperature swings?

Martin

[ghurd]

I was thinking something super simple,

maybe a couple blue plastic 55 gallon drums of water?

maybe with gravity flow near the stove?

I don't think it would take much to make a pretty big difference in most of the similar places I visited.

My French is mostly limited to "Je prendrai le hamburger deluxe avec fromage", "Lebres le Blue", and "oo ee a'la rue o de plan?"

And I'm from 1 county south of you, if you couldn't tell.  :/

G-

[Simen]

I does not know what standards are used in USA and Canada, but here in Norway where we can have hard winters and hot summers, i think most pipes are buried at least 4-7' deep, and they come up from the ground inside the walls.

And the foundations of the houses are isolated underneath and at least 7 feet outside the walls in the ground (with styrofoam); both to prevent the cold creeping beneath the foundation and into the house, and to prevent ground-freeze damaging the foundations.

I'm no expert, but that is how we built the foundation for my mothers house up at 69deg. 58' north...

[mdntdncr]

It seems like you(non specific) have aversion to using a septic tank.  Is this because of the pollution hazard? or just the cost?  or is it not 'green' enough?  

  My friend build a house whereby they used a septic system.  However, the septic also had agents to breakdown the matter, neutralize it, filter, (transforming it into gray water which was then used in a sprinkler system to irrigate non-edible landscaping.  The septic never got full because it was constantly being emptied as the waste water was degraded and organically treated.

  I'm sorry, I don't know the details; only the overall idea.  I've always planned to use it on the house I'll build out in the country.

[mbeland]

That is also the way we do it in normal houses, However, cabins are sometime built with the aim of reducing costs to a minimum and cutting on the foundations by using concrete posts may have a large impact on construction costs.

[mbeland]

Sorry for the use of French, although within brackets. It's just that I was not sure of the right term to convey my thought. After googling a bit I found that a "poele de masse" is a masonry heater. Now we both have learned something Glad to know where you are from! No I couldn't tell apart from the fact that I assume a large proportion of this forum's members are from the states.

By gravity flow do you mean a convection loop powered by the raising of heated water and piping between the drums? I am not sure I get your point. Why not just siting the 2 drums close to the stove and rely on the convection loop within the drum?

Thanks for your help

[ghurd]

The convection idea was so the barrels could be set in a different pattern or something.  Couple barrels near the stove would be just as good.

I am not sure if any of it is a great idea.  It is mostly just an idea.

I have seen some simple gravity fed systems that move heat from a wood (coal) stove to another area.  Such as under the wash room floor to keep that room a little warmer.

I have also seen heat drawn from the (coal heated) hot water storage tank via air, fed into a wash room air vent to keep it warmer, and it works very well. Which is probably why the idea came to mind.

G-

[GaryGary]

Hi,

One thing that I think is important is that these cabins should be able to go cold without damage to the plumbing.  It seems to me you don't want to have to keep a bunch of cabins that will not be occupied a lot of the time above freezing.

This is fairly easy to do.  I used to be one of the volunteers at a non-commercial, weekend only ski lodge, and we had a simple system to drain the plumbing so that the lodge could go cold when not in use.  There were a couple values down low that 1) shut off the supply, 2) opened a drain line to outside.  Then you went around the lodge and opened up all the faucets, flushed all the toilets, ...

This system had been in use at this lodge since 1920, so I guess its pretty well proven

The only caveat is that all the plumbing runs need to have a slight slope down toward the drain -- this is pretty easy to do.

This lodge was also set up to have not electricity inside the building when not occupied -- buildings in the woods mostly die by burning down, and having no electricity in the buildings took away one major cause of fires.

On the stove, you might Google for "Rocket Stove" -- these are very simple stoves that incorporate thermal mass.  You burn a small charge of wood hot and quickly, which heats up the stove mass and provides heat for a long time.

On the hot water, it would probably be best to try to do as accurate as possible an estimate of hot water use.  I would guess that it would be lower than a families at home.  Given that, you could use the usual guidelines for sizing solar water heating systems to get an idea of collector area and storage size needed.

Gary

[scottsAI]

Martin,

Researched this stuff while designing a Net Zero Energy Home. Not built.

PEX piping is freeze damage resistant and can expand and contract as water freezes and thaws within the tubing. No tubing material is freeze-break proof, however, and PEX should be installed using the same locally-prescribed insulation requirements to prevent freezing of any plumbing system.

http://www.ppfahome.org/pex/faqpex.html

Rain water collection, Skip the well.

http://www.arcsa.org/

http://www.harvesth2o.com/

Gray water - http://www.oasisdesign.net/index.htm

Reduces load on septic system. Not costly to implement.

Aerobic Septic System (ATU) requires air pump. Water can be discharged to surface of land. Once saw a dual system, first stage standard (anaerobic) septic followed by Aerobic Septic System, claimed could discharge water into lake or stream. Many designs available, MUCH researching required to get something your configurable with. Your system requires a pump (up hill), may as well send clean water down hill. Cost is 2x+. Use wind powered air compressor?

Newer ATU have a small anaerobic tank (often called sludge tank), because of its small size requires pumping more frequently than a normal septic system requires.

http://www.inspect-ny.com/septic/altaerobic.htm

Wind induced ventilation. Tightly sealed homes require outside ventilation, use the wind.

Have fun,

Scott.

[frackers]

My place is out of the city and as such we have a septic tank and well water.

Same idea, the waste water is filtered and pumped into a 'drainage field' - 6 years old and it might need emptying in another 3-4 years. The drainage field is an area about 5m by 15m of gravel 1m deep that has a grid of perforated pipes i it. Suitable for the soil we have here because it sits over 5000m of shingle which is a great natural filter.

The main thing is to get it serviced every year - check the condition, clean the filter, make sure the pump is working. Also, no bleach or harsh cleaners - it poisons the bacteria in the tank... They are expensive and heavy - ours is concrete, about 2mx2mx3m (the top is buried about 1m below ground level) - but should last forever even if the drainage field has to be re-sited every 20 years. It handles 3 bathrooms with no problems...