# New Solar House design



## painterswife (Jun 7, 2004)

Sometime in the next year we will build our home.

It will be solar with radiant floors and solar hot water. Solar power or wind power wil be added as affordable.

We are trying to work out the best way to handle lowering our need for fossil fuel on cloudy or stormy days.

We can use mass combined with an active storage system
-water, sand etc that could be under the garage floor
or more insulation to reduce the need for heat.

We will have concrete floors and can do concrete walls as well. This means an efficient solar design and systems to keep the heat in for windows and doors at night


This will be in Northern Wyoming. We will not have an air conditioner( we don't have one now). We can not have any wood burning due to allergies.

What would you do?

An active mass storage system?
More insulation during construction?
What would be more cost effective?


----------



## OntarioMan (Feb 11, 2007)

It all starts with building a "better box" - the more efficient the box, the less energy you'll need to heat or cool it.

Mention the words "environmentally friendly" - and many will immediately associate it with solar, wind, water, etc. etc. Intelligent use of electricity and fossil fuels can still be comparitively "enviromentally friendly" - and may actually be much more economical.

North American culture recycles carboard, glass bottles (since when is sand and wood so precious) and wastes gasoline and electricity - all while we sit around talking about hydrogen generation, new technologies and solar/wind power.


----------



## Metcalf (Feb 15, 2007)

I would look into an ICF and SIP building system. These are extremely efficient. Build a little smaller than you might have thought to cut cost and conditioning needs. Good southern exposer will add a lot.


----------



## wy_white_wolf (Oct 14, 2004)

Solar in Teton county, (excuse me if that's not right) better go with lots of insulation and an active mass storage system. Since you are in an area that has about a 50% chance of being cloudy in the winter both would be needed to really cut down on the use of a backup heating system.

Added: Have you seen Solar Gary's system in the lastest MEN. He posts here alot. It looks like a fairly easy system to build and install.


----------



## painterswife (Jun 7, 2004)

Not Teton County, we can't afford that! Park or east of there.

It will be an efficient design that uses solar to the max. I will use ICF's of SIps but would really like a combination, SIPs on the outside with concrete on the interior with no insulation to impeded the mass.

I am trying to figure out( given one good design) if I should spend the money to superinsulate or have a seperate large heat storage,


----------



## SolarGary (Sep 8, 2005)

Hi,

An active mass storage system?
More insulation during construction?
What would be more cost effective?


I guess you need some easy to use tools to let you estimate the savings for each of these methods?
The insulation one is pretty easy -- you can use my home heat loss calculator:
http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm

It lets you put in wall, floor, ceiling insulation levels, and see the results in fuel used and dollars. You can try adding more and see what you save.
Let me know if you have any problems using it.
It does not account for the beneficial effects of the thermal mass within an ICF wall. The report here:
http://www.builditsolar.com/Projects/SolarHomes/constructionps.htm#ICF
(first entry) shows what this effect is -- basically ICF's behave like a stick wall that has about 1.5 times the R value.

The other thing you need is how to estimate heat production for an active system. 
One kind of crude but simple way that I use:

- 1 sqft of solar collector is going to see about 1700 BTU on a sunny day.
- If you recover 50% of this to your storage tank, thats 800+ BTU per day

So, if you build 200 sqft of collector, you should be able to store (200)(800) = 
160000 BTU on a sunny day. This is equivalent to about 2.2 gallons of propane burned in an 80% efficient furnace.
So, if you can make an educated guess at the number of sunny days you get, you can get an idea how much fuel a given area of collector might save you.

You might be able to use the radiant floor slab to store some active solar heat.

This is just my gut more than my brain talking, but I'd say that if you:
- Do a good job with the thermal envelope -- insulate very well
- seal the house up well (watch the builders like a hawk on this)
- have good windows
- make the home as small as will serve your needs
- do a good passive solar layout with solar windows to the south
- provide a way to insulate the windows at night

If you do all that, you are going to likely be down to 25% (maybe less) of the energy use of a conventional home, and that you may really not need the active solar for space heating.

----------------
Some other random information that may (or may not  ) be helpful:

- Think about incorporating an attached sunspace. This gives you some additional solar heating for the house, and can provide some nice additional living space.

Here is an interesting and fairly simple design that does 100% solar in a tough climate. Its sunspace based.
http://www.builditsolar.com/Projects/SolarHomes/shurcliff-saunders-1.pdf


- This is the active system I use:
http://www.builditsolar.com/Projects/SpaceHeating/SolarShed/solarshed.htm
Its 240 sqft, cost about $4000 (with me doing a lot of the work), and I figure it saves about 340 gallons or propane a year in a climate similar to yours.

- Of the solar projects I've done, this is my favorite:
http://www.builditsolar.com/Projects/SpaceHeating/SolarGarageCollector/garcol.htm
The reasons I like it are that it collects heat very efficiently, is cheap to build, and it makes the shop that it heats a place you just love to work in -- warm with outstanding lighting.
I only mention this because I think you might be concentrating on energy efficiency more than you should (never thought I would say that to anyone , and not thinking as much as you should about making this a place you are really going to enjoy living in. Solar homes can be really really nice to live in with the right kind of layout and sun exposure of each kind of room.

- The Earthship design accomplishes everything you want to do (and more). If you have not looked at it yet, you might want to:
http://www.builditsolar.com/Projects/SolarHomes/constructionps.htm#Earth
(2nd entry).

Gary


----------



## painterswife (Jun 7, 2004)

We think we have found an ICF product that will accomplish what we want with interior mass and exterior insulation.

http://www.tfinsulatedconcreteforms.com/

We will use this product with a twist. Instead of using the foamboard on the interior of the wall, we will use magboard(magoxide board) attached to the metal and used as the interior form. We will run conduit inside the wall for all wiring before pouring the concrete and then add more foamboard to the exterior for greater r-value. We have checked with the company and it has been done before.

This will give us all the thermal mass we need and we should be able to do alot of it ourselves.


----------



## AnnieinBC (Mar 23, 2007)

Just a thought, If you are starting from scratch, you might want to take a look at Geo-thermal Systems. Removing the heat from the ground below your house is a very efficent way to heat. Merry Christmas


----------



## arbutus (Jun 8, 2006)

Check out geothermal heat and spray foam insulation. Spray foam insulation is a closed cell 2 part epoxy where an inch of the stuff is about R7. My brother in law just built a regular stick built house - and had his 2x6 exterior walls filled flush with the stuff. He is in a wide open area in west Michigan and gets lots of cold wind this time of year. His furnace (45000 btu) kicks on for a couple of hours max at night. During the day he runs a ventless 30000 btu gas fireplace - for about three hours total. He uses standard electric bulbs because the heat from those helps. He also has lots of southern exposure windows, and that is where the dog lays all day long.


----------



## mdharris68 (Sep 28, 2006)

This is the way I will do my house whenever I build it. 


Make a solar collector out of the entire south side of your house, and direct the warmth under your house. i.e. Make a hallway 4-6 ft deep as wide as your house and glaze floor to ceiling with good windows. Build a double concrete floor system with 2-3 ft piers between the bottom and second concrete floor and fill the void with boulders. Pull air out of the collector between the two concrete floors and store the heat in the boulders. It's nothing more than a large mass to store your heat. It will release heat all night. In the summer, get the coolness of the earth out from under your house. 

I think passive heat is the only way to go. Keep it as simple as possible.


----------



## painterswife (Jun 7, 2004)

The house will be built with long with all rooms( other than storage and bathrooms) with south walls and windows. We will provide any extra heat with radiant tubes in concrete floors. Solar hot water should provide most of the hot water needs.

"Build a double concrete floor system with 2-3 ft piers between the bottom and second concrete floor and fill the void with boulders. Pull air out of the collector between the two concrete floors and store the heat in the boulders. It's nothing more than a large mass to store your heat. It will release heat all night. In the summer, get the coolness of the earth out from under your house." 

This is an option but I think we would go with the option of a cistern under the garage floor. This would provide more heat storage in a smaller area and also be a backup supply of water. I prefer this over geothermal as we can handle on the plumbing and pumps ourselves. 

We have still not crunched the numbers on doing the cistern or putting that money into more insulation. They both have benifits and drawbacks.

We prefer concrete rather than stick built for fire and wind considerations.


----------

