Solar passive block house

[lonecoaster]

Does anyone have any input or experience with block homes?
thinking of building one, any pros or cons? Best heating systems, etc.
Would appreicate any help.

[gpbullock]

Concrete is a low level passive insulator, in that it is so (comparatively) dense it has a rapid heat storage and heat release. In CA. it is given an R3 insulation value. One method for using CMU block is a double layer of block with the air void helping to create a barrier which increases it's insulating ability. Ironically, it's ability to insulate from the sun is better in summertime than it's ability to retain heat in winter time from interior and exterior ambient temperatures, so cold temps are not kind to CMU built houses. A better alternative would be Pumice-crete which is typically thicker wall sizes for similar heights and the porousness of the pumice creates air voids which will hold and distribute passive temps better than a closed cell concrete product would. My absolute favorite passive material is "rammed earth."

http://www.pumicecrete.com/

http://rammedearth.com/re.html

[lonecoaster]

We have fairly long winters here in upper mi., that was one of my worries also. A builder friend of mine suggested the block house idea. he said do all the walls with block, then anchor nailers to the exterior, then insulation boad, then siding. Same on interior walls, then drywall, rock, or wood. The walls end up being 9 1/2 " thick. Some of the plans i looked at used a planter wall on one side. I only have 2.7 acres, all very rocky. He did the numbers in comparison to a stick built. It was $32ft. stick, $34ft. block. The stick walls were drywalled. Block just the insulation on the outside. Cost is a factor is an issue, not a lot to work with.

Thank you for the info.

[rdf]

An option is to go with the stick house, and plaster it inside and out.

Best insulation there is. Call a plastering contractor and get a figure.

[baldfatdad]

There are some books by a man named Charlie Wing. One was: From the inside out. I don't remember the others. He was a professor in Maine. Told his students you could buy an old farm house, have someone insulate it for you and it would pay itself off. They told him to prove it so he bought a house and did. Then he built a house even better.
From those books I made my own water pre-heater, my own furnace system and insulated my place. So much that the electric and gas companies sent people out to see it I was stealing their stuff. I lived in Wisconsin and took my heat bill from over $100 a month to around $30.
I helped a buddy of mine with the ideas for his place in the mountains of Colorado and his winter heat bill was about $9 a month, for a 3600 sq ft house.
Remember and investigate, that most energy saving stuff has great tax breaks.

[wtf]

There are some books by a man named Charlie Wing. One was: From the inside out. I don't remember the others. He was a professor in Maine. Told his students you could buy an old farm house, have someone insulate it for you and it would pay itself off. They told him to prove it so he bought a house and did. Then he built a house even better.
From those books I made my own water pre-heater, my own furnace system and insulated my place. So much that the electric and gas companies sent people out to see it I was stealing their stuff. I lived in Wisconsin and took my heat bill from over $100 a month to around $30.
I helped a buddy of mine with the ideas for his place in the mountains of Colorado and his winter heat bill was about $9 a month, for a 3600 sq ft house.
Remember and investigate, that most energy saving stuff has great tax breaks.

Dang, I would take your high heating bill at a 100, my electric bill runs on average 250 for the summer and winter.

[Van Quad]

Does anyone have any input or experience with block homes?
thinking of building one, any pros or cons? Best heating systems, etc.
Would appreicate any help.


My experience was working with an uncle in Lakeland, Florida, building houses. Those block walls make my thumbs ache. We spend hours struggling to attach vertical furring strips to the block walls with concrete nails. Now I'm sure there's some air tool that does it but back then your thumbs took the beating.

I built a stick solar house back in Nova Scotia. You can load lots of insulation into the walls and sheath them with more insulation.

Best heating system: in my opinion direct exchange geothermal heat pump (http://en.wikipedia.org/wiki/Direct_exchange_geothermal_heat_pump)

[lonecoaster]

Thanks for the replies. We thought geothermal, but our land is rocky and to drill vertical would be expensive. I'm starting to think stick built is all we are going to be able to swing. My wife is a giant granola cruncher. Wants it small and energy efficent as possible, she likes to be green. Wonder what she'd think about a green trailer.

[Rustyjames]

Concrete block has high embodied energy, so it's not really "green," although it is an excellent thermal collector and storage material. But another way to look at it is that it's recyclable and long lasting.

[lonecoaster]

Well that was a pleasant surprise.

[zagam]

Solar passive house is heated during the day by sun in winter from properly shaded equator facing windows or cooled during the night by opening the windows. Passive solar buildings are passive and have no active heating or cooling.

Concrete is bad as it has low thermal insulation or R value.

In addition to R value you need thermal capacitance C.

The product of these has the dimensions of time and is proportional to how long the building takes to respond to temperature changes.

This thermal capacitance actually contains latent heat of air which is significant unlike "thermal mass" which is the small specific heat of solids which would result in a time constant too short to be useful. For R value to work the building must be sealed when windows are closed to prevent loss of this conditioned air.

See my web site http://www.acima.asn.au/ for info on thermal insulation which provides the R part of this equation. See also http://www.cellulose.org/

[zagam]

My calcs http://www.acima.asn.au/solar.cgi with the required source code http://www.acima.asn.au/solar.ksh does solar calcs for southern hemisphere. Refs in the code do calcs for northern hemisphere.

It important that sun dues not strike window when heating is not desired and important that it does when heating is desired.

http://www.usc.edu/dept/architecture/mbs/tools/vrsolar/Help/solar_concepts.html

[jody]

I lived in two block houses. cold and damp.

rammed earth is warm in winter cool in summer.

I was looking at cob houses, and cordwood construction is really interesting.

[jody]

.......

[jody]

the center space is filled with sawdust for insulation.

[jon 0]

http://www.sips.org/

seal your thermal envelope well.

if you want to go green, try the already mentioned cordwood house. straw bail construction. if you want super crunchy look up "earthships"

heating, pellet or wood stove. or cheat and just get a standard electric heatpump and buy green energy.

[beecee]

you could also look into insulated concrete forms
part of building green has to do with building with readily available material
not trucking exotic materials to the jobsite

[zagam]

There was a myth of thermal mass. In reality mass holds some heat and called heat capacity. However, its effect on the buildings response to temperature variation is too short to be useful.

Cavity filled walls filled with insulation will work with latent heat within the building air.

The only thing that stores heat better than air is water and phase change materials. Putting a water tank inside or under the floor could hold a lot of heat.

You can move heat opening windows or retain it by closing them. You can use the air to store solar gain in winter.

For those who can't operate shading and ventilation some thing like air-conditioning without the energy use (http://www.pcpaustralia.com.au/hetac.html) could be used.

I am not sure what you mean by blockhouse if its not a small, isolated fort in the form of a single building.

You need to have winter sun unimpeded. You also need to be able to ventilate it when desired. In Mexican houses they have courtyard and patio for shade. They use courtyard for stack effect to change air. In a temperate climate you would angle the patio above the winter solstice to ensure full sun in winter.

My company manufactures insulating blocks (for use in Australia), but we have still not killed the "thermal mass" myth. See Mud walls give poor insulation: CSIRO (http://www.csiro.au/files/mediarelease/mr2000/RammedEarth.htm)

[lonecoaster]

Thanks for all the replies, but when reality stuck we found we didn't have enough green to go green. We did purchase a house, still waiting for the closing. I didn't realize that it took so long, worried about having it ready before winter. Needs a lot of work.

[gpbullock]

Here in CA. R-value was given such a level of importance that title 24 efficiency compliance was mandated. However, they soon realized that the houses have become too tight in that they didn't breath enough and were having issues and have enacted a mandate for WHV (whole house ventilation) requirements were you are expected to have a dedicated fan, operating 24/7, drawing outside air into the conditioned space. Makes sense. Especially here in the Mojave Desert where ambient temps. are +110 in summertime. So, add +110 outside temp air to inside air conditioned space to make up an over-reliance on R-values which really are only important in wintertime while the heater is running. Here the winter lasts all of two months.

For my location, an 18" thick rammed earth wall house would be a world of a difference to a 2 x 6 stick framed wall with an R-19 value. Passive heating/cooling doesn't mean zero heating or cooling systems. They are still installed but are only necessary to create the small difference in temps. to maintain a comfortable temp., over time enabling a greater savings in energy costs due to a smaller amount of energy used to make up this temp. difference.

[eeezygoing]

THERMAL MASS ALLOWS YOU TO STORE FREE SOLAR ENERGY!! IS THIS WRITING BIG ENOUGH TO GET YOUR FUUL ATTENTION?

Here in Australia I built a Rammed Earth House that is heated by the sun in winter and bottled gas when the sun doesnt shine. The house literally has tons of thermal mass. This thermal mass is not a deficit. It is in fact, the best thing since sliced bread for energy efficiency. The sun heats the walls and floor and the thermal mass stores the heat during the day, so that in winter when the sun goes down at night, the thermal mass continues to heat the internal air all night and the house is cosy and warm without any need to turn the heating on. How anyone can say that thermal mass is no good is beyond me. The house also has double glassing and r3 batts in the roof. The house gets no hotter than 26 degrees Celcius in summer with no airconditioner at all! Friends who live in badly environmental houses, who come to visit me in my house in the summer, literally ask me "Oh do you have the aircon on?" and I literally have to prove to them that there is no airconditioner. They are stunned by the coolness in summer cos they enter from outside which is at 40+ degrees celcius in summer and I have to explain to them why.
Thermal mass does work and it works very well. The house is 320 square meters in size and is made of Insulated Rammed Earth.
Energy cost per month for 320 m2 house is $7.50 AUD of bottled gas

The bottle delivery guy is baffled why he only has to come every six months to refill.

Make sure you use thermal mass in your construction, cos it is good ok!! It will save you money all year round.

THERMAL MASS ALLOWS YOU TO STORE FREE SOLAR ENERGY!! IS THIS WRITING BIG ENOUGH TO GET YOUR FULL ATTENTION?

[trekker6]

american ingenuity dome homes have very high insulation ratings supposedly 60% more than normal, plus they are virtually hurricane proof, according to their numbers, the shell itself is substantially cheaper than typical homes, they aren't the prettiest homes though although you could paint one to resemble a ladybug, or a giant bloodshot eye, would be amusing for the pilots flying over you, oh yeah the segments are reinforced concrete.

[trekker6]

I believe charlie wing wrote a book on living on 12 volts, that was my bible when I lived on a sailboat.