# Point me in the right direction, small, new, energy efficient home



## juanni (Dec 2, 2012)

Well I have been searching and reading through the threads and really haven't stumbled upon my situation.

I will be building in Montana a single level 1200 sf ft  home of ICF with a suspended concrete slab and hydronic floor heat.  Very well insulated.

Only energy available is propane, heating oil and electricity,,, and wood lots of softwood only.  Pine, fir and larch.  I have lots of experience cutting wood and already have the saws, hydraulic splitter, trailer and the wood is free to almost free.

Water table is 8 ft below grade, so not sure it that is good or bad for geothermal?

So what kind of system is practical for my size home? 
I gather that boilers really aren't made for smaller homes?

Somebody point me in the right direction.

THANKS.


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## Bob Rohr (Dec 2, 2012)

juanni said:


> Well I have been searching and reading through the threads and really haven't stumbled upon my situation.
> 
> I will be building in Montana a single level 1200 sf ft home of ICF with a suspended concrete slab and hydronic floor heat. Very well insulated.
> 
> ...


 

Run a heatload calc first.  Don't be surpriced to find a load under 10 btu/ square foot on a tight ICF home like that.  The last ICF home like that I was involved in, about 1700 sq ft, the floor rarely kicked on.  The lighting, appliances and internal heat gains warmed the home on all but the coldest days.

I'm a long time radiant contractor, but I'm begining to think radiant may not be the best system for a tight home with low loads, especially with a high mass slab to flywheel up and down.

My idea would be some radiant in the bathrooms, maybe even electric mat under tile.

If you really want hydronic, consider panel rads.  They respond quickly, are able to be easily zoned with TRV and easy to instally.

A heat pump mini split would be another option as you will need to move some air, and a heat recovery unit to bring in fresh air.  Throw a couple KW of PV and offset the operating cost of the HP.  With PV under a buck a watt and mini split HPs running 17- 22 SEER, that's a tough act to beat.

The load calc will help you nail down a few options.  In a small tight home, if you want some wood heat consider a nice sealed wood stove.  Or the gasification parlor boilers like they use in Europe.  Those provide hydronic and DHW.

Don't forget solar thermal.  Where in Montana?


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## benjamin (Dec 2, 2012)

Turn around and go directly to builditsolar (dotcom). A great site with lots of cutting edge ideas and even more way over the edge ideas.

I agree that a small tight building loses lots of the advantages of radiant heat, but what else are you going to use? Unless you get efficient enough to only need a couple of electric baseboards, you're probably going to end up with a "central" heating system, and radiant can be very simple and effective. http://www.radiantec.com/systems-sources/open-system.php this system might work good for your situation, combined with water to water geo and solar instead of propane.

The water table is one factor in geothermal installation, rocks and available acreage are more often problems.

I'm wondering how a suspended concrete floor is going to work with ICF, are you going to have just the exterior insulation outside of the edge of the floor? skeptical of ICF's here, especially since all of that wonderful mass is is lost inside of insulation.


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## juanni (Dec 2, 2012)

OK, I should have stated that I doubt solar is an option.
My property is located in the bottom of a very steep East-West canyon.
Directly to the south/east is a large knob which blocks out 3 hours of sunlight except during summer.
So I get 2 dawns for every morning. lol

From late fall to spring I would get very little direct sunlight, made even less so from the usual rainy/snowy weather of winter.

Because of the location, and construction of the the home I don't believe I would need or use cooling in summer.

The ground is basically alluvial fill. 1" of soil and nothing but peddles, rocks and boulders from there on down.

I should clarify that I am not exactly doing CIF, instead in will be site cast  tilt up, 5" of concrete on the exterior face with 3" foam sandwiched between 3.5" non structural metal studs.

I want concrete on the exterior, not stucco over foam because of the woodpeckers and wildfire risks.

Oh and I am 50 miles west of Missoula, MT.


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## Bob Rohr (Dec 3, 2012)

juanni said:


> OK, I should have stated that I doubt solar is an option.
> My property is located in the bottom of a very steep East-West canyon.
> Directly to the south/east is a large knob which blocks out 3 hours of sunlight except during summer.
> So I get 2 dawns for every morning. lol
> ...


 

You might enjoy this site. www.danchiles.macmate.me/rockspan/RockSpan/Shop,_Stage_4.html

This is a friend in Missouri building a concrete tip up home for tornado alley. They installed pex tube in the concrete walls, ABC wall system. On the outside as a solar collector, the tube on the inside gives him radiant walls instead of radiant floors, but it is still a fairly high mass system.

I'm leaning more towards low mass, quick accelerating systems for tight homes where wide temperature swings are possible.

Radiant walls under sheetrock, or panel radiators are two systems that I have installed with excellent results.

Skip the AC in your climate, maybe a ceiling fan, but still look into an energy recovery unit to exhaust kitchens and baths and bring in fresh air.

"Heating a Thermos Bottle house" by John Siegenthaler is another good read,

www.pmmag.com/Articles/Column/c14ebdd039aae010VgnVCM100000f932a8c0____


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## benjamin (Dec 3, 2012)

That Rockspan link makes Gary's builditsolar look kinda square.  

Now, removing foot from mouth, no solar-got it.  Have you considered ICF's, they're not great insulation and the mass is lost in the middle of the insulation, BUT they have the great advantage of continuous insulation, which I'm afraid you would lose with the steel studs and/or floor to wall connection, or am I missing something? everything?

I'd guess you've ruled out conventional ground loop geothermal, have you considered open loop/"pump and dump"? or do you just want to burn wood and figure out the best way to do it?


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## PassionForFire&Water (Dec 3, 2012)

Look for hydronic wood stoves or hydronic fireplace inserts.
www.Hydro-to-Heat-Convertor.com


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## juanni (Dec 3, 2012)

benjamin said:


> Have you considered ICF's, they're not great insulation and the mass is lost in the middle of the insulation, BUT they have the great advantage of continuous insulation, which I'm afraid you would lose with the steel studs and/or floor to wall connection, or am I missing something? everything?
> 
> I'd guess you've ruled out conventional ground loop geothermal, have you considered open loop/"pump and dump"? or do you just want to burn wood and figure out the best way to do it?


 
I am open to any practical, cost effective ideas.

I actually have used ICF before, but I don't think they are the best solution for my situation in my location.

I am pretty remote in a very low populated area, delivery costs for non mainstream proprietary products is expensive.  So is bringing in skilled workers to do stucco, plastering etc....  That is why I want to use standard, typical building materials and products.

The same goes for anything too high tech, there is simply no persons or businesses close to advise, sell, install or service such products if they needed to be in the future.

So to my precast panels....
I have a small mini batch plant and equipment to lift and place panels.  By casting them myself I can work around the weather and the obstacle of finding even unskilled labor.
Not having to include a redi mix company is huge plus too, since they are difficult to schedule.
As posted above, I want a hard concrete finish on the exterior surface because of the peckers and do not want to have to stucco it.  The exterior of the panels will be finished when cast.

I plan on embedding threaded nuts in the interior face of the panels.   Screwing in threaded rod 5/16" on 24" centers.  Between the panel and the studs will be 3" of foam board. The metal studs will fasten to the threaded rod.  I can't imagine much heat transfer though those rods, through 3" of foam board.
So yes the insulation is continuous.

I have plenty of experience with drywall hanging and finishing.  Plus I like the ease of remodel repair if needed.

Geothermal is definitely an option.
There is a shallow 30' existing well in place,,,, right in the building footprint or close to it.
So I plan on drilling another deeper well.  The old well could be used for the dump.

I would like to incorporate wood into the heating plan.  The existing shop is wood heat so I already have to get wood anyways and as mentioned it is free or almost free at $20 for 4 cords on Forest Service land.  And dead beetle kill is everywhere.


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## juanni (Dec 3, 2012)

Thanks Bob!

That is a good article by John Siegenthaler.
I like the idea of partial radiant floors, placed only where they are needed.


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## benjamin (Dec 4, 2012)

You're not afraid to get your hands dirty and try some new things on this one, huh?

Open loop geo seems like a good solution, just get your water tested and know what that means in terms of cleaning your heat exchanger.  The units are relatively easy to install DIY (no freon hookups, just water).

I don't have any good solution for burning wood, unless you want to build it yourself? Kinda hard to justify $10-12k+in boiler-storage for such a small load.

I'd like to try tilt up concrete someday, but I imagined the thick section inside with a wood "larsen truss" with cellulose and real portland stucco on the outside.  Your plan sounds solid, only thing I'd consider is cellulose, but that depends on a whole bunch of other factors.


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## juanni (Dec 4, 2012)

benjamin said:


> You're not afraid to get your hands dirty and try some new things on this one, huh?
> 
> Open loop geo seems like a good solution, just get your water tested and know what that means in terms of cleaning your heat exchanger. The units are relatively easy to install DIY (no freon hookups, just water).
> 
> ...


 
No I don't mind, I have a lifetime of getting my hands dirty. lol

I have lots of construction/metal fab/machining experience,,, but none in alternative heating. Everything prior was in the city, on city water, sewer, nat gas, etc...

Yes open loop seems a good solution, and I will get the water tested. I did pull the existing well's jet valve at the bottom of the well. Been down there for 10 years and did have some iron bacteria crust and slime,, but not gobs.

I really need to explore the wood options a bit more. It dawned on me today that perhaps I could put the woodstove/boiler in the shop and pipe the water to the house.

The shop is 1000sq ft, 2x6 framed, 9' ceilings, well insulated, but drafty with two 10' wide x 8' high rollup doors.
Even so, I typically only burn 8-12 decent size pieces of pine or fir a day to keep it quite comfortable for working.
And the stove is an "airtight" from the 70's or so,,,,,so it can't be too efficient.

It is about 75' from the shop to the edge of the house.

Perhaps I can find a model that would both heat the shop and supply hot water to the house? Without overheating/underheating one or the other.
Of course I would need an alternate method for when there is no need to heat the shop.


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## Chris Hoskin (Dec 4, 2012)

I love the idea of a wood boiler with thermal storage located in the shop.  Keep the wood out there, dry and warm and 75 feet to the house is no problem.  You might even be able to get away with 1" pipes underground because your heat load is so small.  Nice high ceilings in the shop so you are able to use a single 400 gallon tank (just over eight feet tall) for a super cost effective and elegant set up.  With storage there is no need to worry about over heating the shop or house - just charge up the storage like a big heat battery and draw off to the shop and/or house zones as needed.  I like Bob Rohr's idea of panel rads, but would also consider constant circulation in a radiant floor (at very low temps).  If you like the idea of setting your thermostats back at night then panel rads, otherwise I like the radiant floor.  Also strongly recommend ERV as indoor air quality can be a real concern in the kind of house you are building.  Keep us posted and drop me a note if you would like more details about the system I am describing.  Chris.


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## maple1 (Dec 4, 2012)

I was thinking a boiler wouldn't be the best solution for your small efficient building - but if you can do a boiler & storage without taking away much living space, I think that would be the best you could do. You could maybe burn something like once every three days to do your heating - with adequate sized storage. That would also handle your DHW in the off-heating season, maybe going over a week between burns.

The only thing that would make me think of alternatives or supplements to that would be possible need for A/C in the summer? Then again, you might get by very well with a single mini-split unti for that if required.


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## benjamin (Dec 4, 2012)

If you do the geo and you have reasonable electric rates, then a boiler can be a low priority.  

You could use your slab as the storage if you don't mind wider temp swings.  Or a sand bed under the slab for more storage and stability.


I cobbled together a boiler with a masonry combustion chamber and a used cast iron boiler core.  I wouldn't recommend putting an experimental boiler anywhere smoke will be a problem, but it might work fine in a shop.  The "heiss" boiler, or a hybrid masonry heater/boiler is similar to what I'm thinking of.


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## Como (Dec 5, 2012)

I think the first thing I would do is move it to where you do get good solar.

I am in a 10,500HDD climate so I am going to assume a higher load. I know people even here with well insulate buildings who have to leave a window open when the sun is shinning due to the solar gain.

I would in your location at least double the insulation. The next question is automation, a wood stove should be fine for your load, so what do you need to cover when you are gone?

So a Stove and whatever you need to keep the building from freezing when you are not there. There are a few stoves that allow you to preheat water.

Or get a Rayburn, cook, heat and hot water in one.


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## StihlHead (Dec 6, 2012)

Solar seems to be a non-option with the east-west canyon location.

I would advise that you avoid heating oil like the plague. Spendy. Porpane is also spendy, but better.

Hydronic is the way to go with space heating. By far the best heat in my experience. My ex's place had hydronic on an electric and we retrofitted it with an OWB. She has more wood than she can burn in 10 lifetimes there, so an OWB was a good option. We went with Central Boiler. Not as efficient as Garn, Tarn or other large water storage systems, but half the price. You can run loops for hot water and space heating, and run 75 feet easy from the smaller OWB models available. If you have firewood, you are set. Fir is good firewood (doug fir that is), and larch is even better. Larch has about 20-22 MBTU per cord, about the same as walnut or maple. Pine is good shoulder season wood.

It seems to me that the higher water table would be good for a heat pump source. Water transfers heat really well (or robs it, depending). Find out if there are others using geothermal in that area and find out about typical costs.


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## juanni (Dec 6, 2012)

Como said:


> I think the first thing I would do is move it to where you do get good solar.
> 
> I would in your location at least double the insulation. The next question is automation, a wood stove should be fine for your load, so what do you need to cover when you are gone?
> So a Stove and whatever you need to keep the building from freezing when you are not there. There are a few stoves that allow you to preheat water.
> ...


 
Huh?
5" of air entrained concrete is R19.5
3" of rigid foam is R11.5
3.5" of Roxul is R15
and you say to double it?

I suspect even a small wood stove without heat storage would drive me out of the proposed home, with the planned insulation.

In my drafty 1000sq ft shop with R22 on the walls and R38 on the ceiling with a 70s era stove Typically, I comfortably heat it with 8-12 decent pieces of pine or fir a 8-10 hr workday.

If I doubled the insulation in the house, I could heat it with a Bic lighter. lol

Here is the 1st paragraph of Bob's linked article...

*Does the term “superinsulated house” ring a bell with some of you? It was a concept first hyped in the 1980s to describe houses with extremely well insulated thermal envelopes. Imagine R-30+ walls, R-50+ ceilings, R-4 windows, and so forth. When you put these R-values into heat load estimates, you may find a 2,000-sq.-ft. house with a design heating load of 20,000 Btu/hr. or less, even in a very cold climate. A superinsulated house might even have a lower overall heating load than the great room of a typical “suburbia” house built to minimum code standards.*


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## Fred61 (Dec 6, 2012)

juanni said:


> If I doubled the insulation in the house, I could heat it with a Bic lighter. lol


Or junk mail. But isn't that the point. Think about future energy costs or the work involved in cutting and handling wood when you're in your seventies as I am. Believe me, it isn't as easy as it used to be.


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## JP11 (Dec 6, 2012)

Remember that a tight house is great for heat.. not for air quality.

A HRV or ERV.. whatever you call it...  You gotta have fresh air.  Some ducts like central air.. even if you never use central air.  Fresh air brought in to keep your house healthy.  Whole house humidifier.  

I agree with the boiler, storage, and wood all in one shop.  Don't scrimp on the underground pipes.  What you put in the shop to heat the water isn't as important as design temps and pump flows.  All simple, off the shelf, controls and pumps.  Easy DIY.

AND.. if you do it that way you don't give up any floor space in the house for your utilities.  Heck.. I'd put my cold water tank out in the shop too.  Back up heat source too!  I'd go propane boiler and heck, put a standby propane powered generator our there outside the shop too.  Main electric panel out there.. with a sub panel in the house.

It's easy to spend someone else's money.. but keep planning.  Keep your mind on what you want it to look like and work like when you are done.

JP


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## mikefrommaine (Dec 6, 2012)

juanni said:


> Huh?
> 5" of air entrained concrete is R19.5
> 3" of rigid foam is R11.5
> 3.5" of Roxul is R15
> ...




R3.9 per inch for ae concrete? Seems a little high to me. Is this standard 6% air entrained, or some other type of concrete?

If one could get that high of an r value out of standard concrete there be no point in ICF construction. Just use standard forms and pour 8" walls and skip the expense of foam forms... Presto r31 walls.


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## juanni (Dec 6, 2012)

mikefrommaine said:


> R3.9 per inch for ae concrete? Seems a little high to me. Is this standard 6% air entrained, or some other type of concrete?
> 
> If one could get that high of an r value out of standard concrete there be no point in ICF construction. Just use standard forms and pour 8" walls and skip the expense of foam forms... Presto r31 walls.


 

All I can say is that is the R value given in every reference I see.
I suspect if it was super air entrained it would say.


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## mikefrommaine (Dec 6, 2012)

Every reference I've seen list concrete at .08 per inch. And air entrained as "slightly higher". Some manufactures of Autoclaved concrete have erroneously claimed 3.9 for their cellular concrete products which isn't a DIY process. But others now admit an "effective" r value of 1.5/inch is more likely for a cold climate for cellular concrete.


http://www.sungardenhouses.com/tech-aac.html


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## Frozen Canuck (Dec 6, 2012)

Yes that number sounds kinda high for the R value of concrete. Typical weight/strength mixture of concrete in an 8" thick wall should yield R1.35 for an 8" wall, uninsulated of course. This may be an R value of an ICF & was simply transposed in the posters thoughts/typing. Makes sense that way. BTW if someone has indeed figured out how to achieve those R values in concrete please PM me with a few details, in my business that's money in the bank.


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## EffectaBoilerUser (USA) (Dec 6, 2012)

Your system sounds ideal for a wood gasification boiler and water storage in your garage. When using storage you simply heat up the storage and then the heat loads pull off of the storage . By having this system located in the garage you are able to get the added benefit of using any lost heat from the boiler/storage to heat your garage.


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## juanni (Dec 7, 2012)

OK, lets say R1 for a 5" concrete wall + R11.5 + R 15 = R 27.5 for a 12" finished wall.
The suggestion was to double the insulation to R 54 which would be a 18.5" finished wall.

Sorry that sounds way over the top, I am not building on the dark side of the moon. lol


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## Como (Dec 7, 2012)

Regular Concrete is 0.08R.

Concrete with 6% bubbles should be higher.

That number seems to come from one source and must be a major typo.


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## Como (Dec 7, 2012)

juanni said:


> OK, lets say R1 for a 5" concrete wall + R11.5 + R 15 = R 27.5 for a 12" finished wall.
> The suggestion was to double the insulation to R 54 which would be a 18.5" finished wall.
> 
> Sorry that sounds way over the top, I am not building on the dark side of the moon. lol


 
The wall in front of me is about R30. If I was building now I would aim for R50. They are forecasting -17F as a low on Sunday, but we will have lots of sunshine during the day. So heating load would be minimal during the day. You do not have that. I know that today the House was fine until the sun started going down.

From a heat sink point of view I think you would be better having the concrete on the inside as that is where your heat source is.

Your initial total for the walls makes sense to me with about 50% extra in the roof.

If you then do a heat loss calculation you should find your peak demand at 10,000 or so for the house which makes a heat source fairly minimal. 3KW in electricity terms as a max.

I do like the ability of a stove a bit too big to put out a lot of heat and take a room from 50 to 70 very quickly.


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## pdf27 (Dec 7, 2012)

juanni said:


> The suggestion was to double the insulation to R 54 which would be a 18.5" finished wall.
> Sorry that sounds way over the top, I am not building on the dark side of the moon. lol


Why? Insulation is pretty cheap, and you only pay for it once. Additionally, better insulated walls mean you don't get cold surfaces with the associated convection currents and hence draughts.

If I were doing the building in that situation, I'd be planning on the R54 as an absolute minimum and looking for more if possible. It doesn't cost you all that much, and if you get it right (which requires a fair bit of attention to detail and a proper heat load calculation) then electric convection heaters become an economical way of heating. That has a lot of advantages (cheap, low maintenence) and the total cost of insulation + heaters will probably be getting close to that of a lower level of insulation plus a hydronic heating system of some sort.


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## Frozen Canuck (Dec 7, 2012)

juanni said:


> OK, lets say R1 for a 5" concrete wall + R11.5 + R 15 = R 27.5 for a 12" finished wall.
> The suggestion was to double the insulation to R 54 which would be a 18.5" finished wall.
> 
> Sorry that sounds way over the top, I am not building on the dark side of the moon. lol


 
Agreed. We typically gets SIP's here that yield R44+- in a 6" panel, however you have choosen to go with tilt up concrete panels in your situation. If you are still in the planning stages SIP's are pretty DIY friendly. A couple can take a 2 day course & learn enough skills to DIY the wall panels in that time. Pretty straight forward in most cases & you only need 1 special tool (beam saw) for cutting the panels on site, or you can order them precut for assembly according to your drawings. I agree with the comment about your situation being right for installing a gasser in your shop & piping the heat from there. Best of luck with the project.


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## juanni (Dec 7, 2012)

Frozen Canuck said:


> Agreed. We typically gets SIP's here that yield R44+- in a 6" panel, however you have choosen to go with tilt up concrete panels in your situation. If you are still in the planning stages SIP's are pretty DIY friendly. A couple can take a 2 day course & learn enough skills to DIY the wall panels in that time. Pretty straight forward in most cases & you only need 1 special tool (beam saw) for cutting the panels on site, or you can order them precut for assembly according to your drawings. I agree with the comment about your situation being right for installing a gasser in your shop & piping the heat from there. Best of luck with the project.


 
I think you missed my reasons for wanting a hard rock concrete exterior. 

1. Peckers would make SIPs look like swiss cheese in a couple of seasons.
2. SIPs would require a hard rock stucco finish, something I can't DIY and there is no one locally who can either. I would have to pay transportation, lodging and living expenses for anyone that would be working here more than a day = $$$.
3. It isn't very fire tolerant, and I live in the woods.


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## mikefrommaine (Dec 7, 2012)

Have you considered fiber cement siding? Not saying tip up concrete won't work but it seems like a lot of work to reduce fire risk. And 'out of the box' house construction generally leads to lower resale values if that is a concern.


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## juanni (Dec 7, 2012)

mikefrommaine said:


> Have you considered fiber cement siding? Not saying tip up concrete won't work but it seems like a lot of work to reduce fire risk. And 'out of the box' house construction generally leads to lower resale values if that is a concern.


 

Actually I think it is going to less work and headache especially when you look at long term maintenance, material storage and repair issues.

I can have the premixed sand/ag delivered by the truckload. It isn't a propriety product, can sit outside year after year and doesn't deteriote. Ditto rebar, mesh, galvanized studs, galvanized floor decking and plate embeds that I fab myself.

The portland cement obviously would need weather protection and does have a shelf life with absorbed moisture.
Admixures need protection from freezing.

The wall panels, shell etc could sit for years uninstalled or erected without deteriotion worries.

The proposed wall panels 9' high x 12' wide are load bearing, high thermal mass, prefinished except for paint and caulking around the perimeter, impervious to bugs, birds, wind, water damage, fire and typical sized falling trees.
Requires zero maintenance other than paint every 10 years and that perimeter caulk every 30? or so.
Other than the insulating foam (I may go a different route) there is nothing to burn on the entire structure = no fire insurance required or very low cost = total that up $$$ over a lifetime.

I don't have to drive 65 miles to a town, Home Depot, Lowes, whatever, only to find out the screws, nails, Simpson connectors, ICF block, SIPs panels, siding or fill in the _____, is out of stock, ordered the wrong size, putting a stop to the project.

I don't have to look for anyone qualified or skilled to help with any part of the project except perhaps the alt heat and drilling the well.
And I don't need a "crew" to pour and finish a 2yd panel, or to install it. Me and someone that can work a concrete rake and a garden hose to clean the mixer and tools every 5 days or so. Even that is hard to find!.

All at an estimated $3 or less per sq ft of wall panel.
What other system comes close?

Finally, I guess unless you have lived in a remote, sparely populated, rural area, you have no idea how difficult it is to get materials, help, contractors, etc.

Anything that I can do that eliminates someone, some product, or weather dependent DRAMATICALLY saves time, money and frustration.

Incidentally, I stopped by one of the plumbing supply places in town and they have a guy that designs hydronic floor systems.
So I went back to his office to talk to him.
I told him of my building plans and was thinking of a hydronic floor system and what would be some good heat source options.
Gas or electric he said.
I said what about wood? 
His reply "you don't want wood".
Asked further he said it is a lot of work, and that he doesn't know anything about wood boilers. lol

That is why I am here.


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## Dextron (Dec 7, 2012)

juanni said:


> Actually I think it is going to less work and headache especially when you look at long term maintenance, material storage and repair issues.
> 
> I can have the premixed sand/ag delivered by the truckload. It isn't a propriety product, can sit outside year after year and doesn't deteriote. Ditto rebar, mesh, galvanized studs, galvanized floor decking and plate embeds that I fab myself.
> 
> ...


 
I would like to give you a vote of confidence, respect and encouragement. I took on a similar project in building a house in a remote area and doing all the work myself. One person who keeps at it can complete a purely amazing amount of work over time.  If you take the time to research things you can do just about any phase of construction and do it just as well as the professionals. I am sure most folks on this forum are the do it yourself types and I mean no disrespect towards any of them but taking on a large project in a remote area by yourself is a whole new level of challenge. It is very satisfying to see the end result and know everything about how it went together and know you did it all yourself.
Best of luck and I am sure your project will turn out fine.


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## benjamin (Dec 7, 2012)

Lots of us have built houses "outside the box". By that hydronic design guy's estimation we're all crazy for using wood boilers. So don't let any of us stand in your way.

Some people have recommended the whole nine yards boiler, storage and backup in the shed to feed a small efficient house. This is nuts. Such a system will work great with that setup, but it makes no sense when a much simpler and cheaper system will work just as well.

I have no experience with tilt up concrete and we have no idea how much experience you have with this system or construction in general. So we're kind of guessing, but the points about resale value, difficulty etc. are valid. Frame construction is easy to do for people with minimal education and motivation, alternative methods only get harder.

edit: or if you're building over time, concrete blocks instead of tilt up?

The thermal mass that's outside of the insulation is useless (unless you have desert sun or big daily temp swings). If it was me, I'd be putting the concrete inside, a larsen truss with 8-12" of cellulose, and stucco on the outside. Stucco is not that hard to do, especially if you don't need it to look a certain way.


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## Como (Dec 7, 2012)

MgO SIP's would be wood pecker proof.


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## pdf27 (Dec 8, 2012)

One other possibility if you're looking at blockwork construction - cavity wall insulation, which is very common in the UK. It's basically a masonry-insulation-masonry sandwich.

If you're building it by yourself I'd certainly have a think about blockwork rather than casting panels in situ and tilting up, if only because the lower weights you'd be handling are easier and safer than whole panels. Each of your suggested panels (5" x 9' x 12') looks like it will weigh almost exactly 3 tons, so you're going to need some sort of crane to lift them into position unless cast in place. If something goes wrong with weights like that and you're trying to manhandle them it can be very dangerous indeed - and from the sound of it you're a long way from help if you need it.


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## Como (Dec 8, 2012)

Celcon type stuff AAC would be easier and has thermal benefits, but it is not widely available, certainly not available in Colorado


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## juanni (Dec 8, 2012)

pdf27 said:


> One other possibility if you're looking at blockwork construction - cavity wall insulation, which is very common in the UK. It's basically a masonry-insulation-masonry sandwich.
> 
> If you're building it by yourself I'd certainly have a think about blockwork rather than casting panels in situ and tilting up, if only because the lower weights you'd be handling are easier and safer than whole panels. Each of your suggested panels (5" x 9' x 12') looks like it will weigh almost exactly 3 tons, so you're going to need some sort of crane to lift them into position unless cast in place. If something goes wrong with weights like that and you're trying to manhandle them it can be very dangerous indeed - and from the sound of it you're a long way from help if you need it.


 
Steel tilting form with overhead crane, all in one.  Will have its own axle, wheels and four 20K? landing gear style jacks.

Place and level form directly in front of footing.
Cast the panel, let it cure 5 days or so. 
Whole form tilts up so there is little stripping stresses on the panel.
Strip panel from form at almost vertical position.
Roll panel into position using overhead crane.
Weld base connections and brace.
Lower form until wheels contact ground.
Roll form/crane 12' over to next position.
Raise form with jacks and level.
Repeat.

The beauty of precast is modular panels, of the same size, same reinforcement, same embeds cast over and over.  With window and door openings of course.


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## juanni (Dec 8, 2012)

Como said:


> Celcon type stuff AAC would be easier and has thermal benefits, but it is not widely available, certainly not available in Colorado


 

I would be curious what the cost of equivalent of 18, 9'x12' of those SIP panels delivered to 59801 would be.
I bet it would not be a economical alternative.


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## juanni (Dec 8, 2012)

Dextron said:


> I would like to give you a vote of confidence, respect and encouragement. I took on a similar project in building a house in a remote area and doing all the work myself. One person who keeps at it can complete a purely amazing amount of work over time. If you take the time to research things you can do just about any phase of construction and do it just as well as the professionals. I am sure most folks on this forum are the do it yourself types and I mean no disrespect towards any of them but taking on a large project in a remote area by yourself is a whole new level of challenge. It is very satisfying to see the end result and know everything about how it went together and know you did it all yourself.
> Best of luck and I am sure your project will turn out fine.


 

Thank you Dextron!!

It wasn't relevant to the topic when I started this thread about alt heating, but I am a licensed PE with a few years of exclusive precast design experience (commercial structures), plus several years of wood frame design, a few ICF projects, was a contractor before/during engineering college, and before that a carpenter.

Currently my hobby is metal fab/machining/welding.

It is going to be OK.


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## Como (Dec 8, 2012)

Winter is coming, 10 as a high tomorrow and -18 as a low.

We are currently renting a house while I work on the Hotel 4" SIP, slightly bigger than your proposed building. All electric plus a wood stove.

I brought 2 cord over from the Hotel, and so far I think that is going to be enough for the winter. Our electric averages less than $3 a day.

I built the Boiler building using SIP's, the only issue I had was with the supplier, a long story. I also used 4" but instead of OSB I had them in MgO, cement board for want of a better description. If it had been a house I would have gone to 6". I modularised the design so I used 4'x8' panels. Still  needed 3 of us, 4 for the roof panels. I am sure OSB would have been a lot lighter. They can go up very quickly.

AAC is autoclaved aerated cement, light weight concrete blocks but with better thermal protection and can be worked with hand tools, I would have used them if they were available. They now use thinset for mortar to minimise joint thickness which would be a thermal bridge.

I looked at the Passivhaus etc standards, and I can see that in Germany they might make sense. But going the extra costs a lot and when you compare it with the cost of putting one more log on the fire when you are surrounded by the stuff, makes not a lot of sense.

Now if you want a Boiler system etc, well go for it it. But I just can not see the economics. A stove has much less to go wrong and is not power dependent.


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## juanni (Dec 9, 2012)

Como said:


> Winter is coming, 10 as a high tomorrow and -18 as a low.
> 
> We are currently renting a house while I work on the Hotel 4" SIP, slightly bigger than your proposed building. All electric plus a wood stove.
> 
> ...


 
But see Como, you are pointing out the issues with alternate construction materials that I am trying to avoid.

Problems with the supplier, 3-4 people required to install, products that aren't even available in a far more populated area than where I live and (I assume) unfinished exterior surfaces with lots of joints.
And we haven't even considered the total delivered costs.

And I will have a wood stove or fireplace in the house, only I don't want to have to use it for primary heat source. I will use it for the pleasure of a fire or in an emergency, but I simply do not want the mess of beetle killed wood having to be constantly carted into the house and having to feed a small stove.

Out in the shop mess isn't a issue, *IF* I decide shop boiler route.
And it sounds like I may have to feed it once a day, feed it for one day or maybe every other/few days.
Plus it can supply my DHW and I have to have a stove/fire in the shop anyways.


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## pdf27 (Dec 9, 2012)

juanni said:


> Thank you Dextron!!
> 
> It wasn't relevant to the topic when I started this thread about alt heating, but I am a licensed PE with a few years of exclusive precast design experience (commercial structures), plus several years of wood frame design, a few ICF projects, was a contractor before/during engineering college, and before that a carpenter.
> 
> ...


That makes a big difference - I didn't realise you've done this before quite a few times! Given that and if you've got cheap/free wood available, the proposed design makes a lot more sense.


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## Floydian (Dec 9, 2012)

Hello juanni,
It looks like you live in a 7700+ HDD (heating degree day) area, is this correct?



Bob Rohr said:


> Run a heatload calc first.


 
I agree with this, first and foremost, and before you build.Run the calc based on whole building assemblies that account for ALL thermal bridges, the bane of any super insulated building.

There are a lot of ways to achieve tight, super insulated construction. This site discusses most: http://www.greenbuildingadvisor.com/

In your climate zone these would be my absolute minimums:

r-5+ windows-this means triple pane, warm edge spacers. Think about the minimum operable windows you'll need for summer time ventilation and fixed units for the natural lighting you will want.
This can save a bundle and and perform a lot better than lots of operable units. South facing units should have a higher solar heat gain coefficient(SHGC) if possible, even though it sounds like you will have minimal solar gain.

r-20+ sub slab insulation, higher for any slab edge detail. Dow Thermo-Mass could work well with your proposed wall assembly.

r-40+ whole wall assembly. I wouldn't count on much r-value from your exterior concrete so you see this can be tricky. Your right about SIPS-definitely one of the more expensive super insulated wall assemblies for a DIYer. GBA has good info on virtually all high performance wall assemblies, as well as BSC-building science corp. Check them out if you haven't.

r-60+ Are you going cathedral or attic? Vented or unvented? So many ways to construct these assemblies it'll make your head spin. See the above sites.

Air tightness of less than 1 ACH/50 is doable with good detailing, and definitely heat recovery ventilation-HRV.

If you insulate to these levels your radiant slab will hardly feel warm in all but the coldest weather. Panel rads, as Bob Rohr suggests, with a floating cork floor over your slab would achieve every bit the thermal comfort of a heated slab the with the added benefit of getting you off of the brutal hardness of concrete. A unheated cork floor can actually feel more comfy than a heated slab in a super insulated house because it conducts less heat from your feet. And I see no benefit to the thermal mass of the concrete if you don't have good passive solar potential. A btu is a btu, after all.

Just some thoughts. Good luck,

Noah


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## juanni (Dec 9, 2012)

Floydian said:


> Hello juanni,
> It looks like you live in a 7700+ HDD (heating degree day) area, is this correct?
> 
> 
> ...


 
Yes that is the HDD for Missoula the closest recorded data that I find.
I am about 50-60 miles away, 200' lower in elevation and have none of the howling winds that Missoula gets because they are located out in a treeless plain.
But I don't get the winter sunshine either.

And yes I will run a heat calc, but I haven't even finalized the floor plan yet,,,, or designed the walls (I suspect 4" concrete will be adequate) or anything else.

I came here for ideas about the alt heating.


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## Floydian (Dec 9, 2012)

juanni said:


> I came here for ideas about the alt heating.


 
I consider proper passive solar design couple with super insulation+tight construction the ultimate alternative heating system.Or the ultimate alternative to complex, expensive heating systems that, IMO, are hard to justify in homes built with low long term energy usage as a priority. Obviously this is your house, so your priorities are all that really matter.

About wildfires: It is my understanding that when a house is subjected to a wildfire, the windows tend to go pretty quick and at this point it really doesn't matter what type of cladding the building has.
Just wondering if you can shed any light on this scenario for me?

Not sure 4" of concrete will keep the woodpeckers at bay!

Noah


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## Frozen Canuck (Dec 9, 2012)

juanni said:


> Yes that is the HDD for Missoula the closest recorded data that I find.
> I am about 50-60 miles away, 200' lower in elevation and have none of the howling winds that Missoula gets because they are located out in a treeless plain.
> But I don't get the winter sunshine either.
> 
> ...


 
Honestly I think Bob Rohr gave you some great ideas. Given what you have said about not wanting the unit in the house, I will assume that your shop will be the new boiler room. Given that, your choices are really unlimited (sorry to say). Any of the boilers that members are using will work in your shop. Once you have a practical load number to use as a base you can if you wish decide/discuss how often you want to feed said boiler. Daily like some members without storage, or add storage & go further between firings. Enough options at this point to make it confusing to say the least. Once you have load info I am sure members will provide plenty of boiler options. There are a few geothermal threads in the green room if you are considering that option as well.


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## juanni (Dec 9, 2012)

Floydian said:


> I consider proper passive solar design couple with super insulation+tight construction the ultimate alternative heating system.Or the ultimate alternative to complex, expensive heating systems that, IMO, are hard to justify in homes built with low long term energy usage as a priority. Obviously this is your house, so your priorities are all that really matter.
> 
> About wildfires: It is my understanding that when a house is subjected to a wildfire, the windows tend to go pretty quick and at this point it really doesn't matter what type of cladding the building has.
> Just wondering if you can shed any light on this scenario for me?
> ...


 
Well as noted way above in this thread, solar isn't a viable option.

As far as wildfires, I am building away from trees of any size that might fall burning onto or near the proposed home. No brush around the house either.
The big risk would be falling sparks and hot ash landing on/near combustible materials. That is why I want no exposed combustibles or even unexposed.

I have burnt massive piles of slash and brush from clearing the property, cutting down dead beetle kill etc,,,, the heat really goes up, 25ft away or so there is no real heat, so I can't imagine anything hot enough to fracture out a window, and if it did what would burn on an all concrete and steel home?
The foam, behind the sheetrock, behind the metal studs, behind the Roxul,,,,not likely.

Oh, and I expect those peckers to try to knock a hole in the concrete or even just enjoy banging their heads against it.
But it isn't going to look like this 4 year old existing well house.








That jammed in tin and paint can lid are covering the large holes.

You fellas, the carpenter ants, the termites, the black mold and the peckers can have my share of the Beaver Board, warping, cracking, 3rd growth, wood products, I have seen the light of concrete and steel.


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## Fred61 (Dec 9, 2012)

The woodpecker pecked on the school house door
He pecked and he pecked "til his pecker was sore


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## Como (Dec 9, 2012)

AAC is not a new product, I used them 30 odd years ago, just not made in Colorado. Stocked by the Home Depot equivalent. If I was going it alone I think I would go ICF. Your system is Concrete and insulation. The size of those panels would scare me.

So a Stove for the shop where you do not mind the mess. A friend who has a large house well insulated uses wood stoves in the house and propane in the shop as he is in randomly and a stove would be not practical. 

I think when you do the calc you will come up with a small heat load that will make any wood based boiler system overkill.

One of the problem with in floor radiant is that it is slow to respond, but your case seems a situation where that is not an issue.

Or you could look at baseboard radiators, not the fin stuff but the ones that replace a wood baseboard with an emitter.


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## juanni (Dec 9, 2012)

Como said:


> AAC is not a new product, I used them 30 odd years ago, just not made in Colorado. Stocked by the Home Depot equivalent. If I was going it alone I think I would go ICF. Your system is Concrete and insulation. The size of those panels would scare me.


 
With ICF we go back to propriety materials, requiring a stucco crew/guy with that soft stucco they now use, plastering the interior instead of drywall, and the far more complicated repairs behind the wall or future remodeling.

And for whatever reason stucco isn't very popular in MT, so I would think there wouldn't be many stucco crews/guys around these parts.

And with 10" Rastra blocks (that is the brand I have used) you end up with a finished wall of about 12" and R24, vs my 5" concrete finishing at 12" and an R27.5. Or R30 plus if I can make 4" work.

ICF has some big advantages in construction, if you can assemble Legos you can assemble ICF. 
You don't need to know how to weld, fabricate or finish concrete. 
You don't need a 12'x12' tilting steel form, I am making it big enough for other projects.
You don't need lifting equipment.
And many of the details are pre designed. 
But in my case those aren't obstacles.

I have lifted and moved expensive and fragile lathes, mills, etc,, that weigh 2 tons a few dozen times, what is a cheap 3 ton panel? lol


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## Como (Dec 10, 2012)

There are different types of ICF and I have not had a hand in them. But one type is to use insulation panels as formers and pour the concrete between them rather than using the lego blocks.. When it comes down to it we are looking at a lamination of concrete for strength and insulation. You are doing the same thing except you are having the thermal mass on the outside.

http://www.hhcelcon.co.uk/by-product/vertical-elements

Similar sort of thing using AAC.

The finish on the inside or the outside are really just a matter of attachment. I have still to clad my Boiler Building, I went with MgO mainly for abuse resistance, but unlike OSB it is quite happy sitting there. I have some bathrooms to fit out and if I can get hold of some more I will use it as opposed to cement board etc.

If I had used AAC I would have just painted the inside, foamed the outside and then whatever finish,

Probably will use Hardie Panel.

As the Boilers are not operating yet and I also have my water system in there I am heating it with a small electric radiator.


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