Category Archives: Energy

Nauhaus Primer: Talking Head About Carbon Neutrality and the Nauhaus Prototype

We recently recorded this video intended as a draft to help us work on our public spiel. It needs a lot of work, but I thought I’d post it anyway because it’s a fairly thorough introduction to what we’re doing generally and the prototype in particular.  Just pretend you’re in high school and lunch is next period…Go generic sports team with some sort of mammal as its mascot!


Carbon Neutrality and The Nauhaus Prototype from Clarke Snell on Vimeo.

Foam Insulation Sprayed

Today, Home Energy Partners came out to spray the closed-cell insulation for the slab and exterior walls.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Advantek sheathing and brick mold are installed first to stop the foam and eventually to support the Hemcrete.
Advantek sheathing and brick mold are installed first to stop the foam and eventually to support the Hemcrete.
Brick Mold Installation
Brick Mold Installation
Home Energy Partners Spraying North Wall
Home Energy Partners Spraying North Wall
Home Energy Partners Spraying North Wall
Home Energy Partners Spraying North Wall
Home Energy Partners Spraying Underslab Foam Insulation
Home Energy Partners Spraying Underslab Foam Insulation
Home Energy Partners Spraying Underslab Foam Insulation
Home Energy Partners Spraying Underslab Foam Insulation
Spray Foam Insulation around Ground Loop Stub-out
Spray Foam Insulation around Ground Loop Stub-out
Spray Foam Insulation on CMU
Spray Foam Insulation on CMU

Gravel and Vapor Barrier

Today, another 20 mil. vapor barrier was spread over gravel, in preparation for the insulation and concrete slab.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Drain and Insulation with Gravel
Drain and Insulation with Gravel
Finished Gravel
Finished Gravel

Vapor Barrier at CMU
Vapor Barrier at CMU
All penetrations through the vapor barrier are carefully sealed.
All penetrations through the vapor barrier are carefully sealed.

Finished Vapor Barrier
Finished Vapor Barrier



Ground Loop

Today, Tim, Billy and other volunteers installed a ground loop, which will be connected to the Energy Recovery Ventilator in the Mechanical Room.  These pipes will be filled with water, and will allow the ERV to take advantage of the constant temperature underground while supplying fresh air to the house.

Click here to view the entire Nauhaus Prototype Construction Chronology.

Ground Loop
Ground Loop
These lines will connect to the ERV.
These lines will connect to the ERV.

Residential Energy Use, House Size and Cost

Why does energy use continue to increase despite the constant appearance of better, more efficient technology?  Given that energy consumption per dollar of GDP is decreasing (energy intensity is increasing), some people might say that energy subsidies are justified, at least in the industrial and commercial sectors.  So, why should energy consumption increase in the residential sector?  By far the greatest single use of energy in the home (almost half) goes towards heating (only 6% goes towards air conditioning) [DOE]–and let’s face it, the climate ain’t getting colder.  If we look at the residential energy use patterns over the years, a surprising trend is visible.  The greatest energy-using states go from the North (in the 1970s) to the South and Midwest.  Something besides a winter storm is brewing.

Price certainly plays a large role.  The states whose per capita energy consumptions were the highest in the last five years of data do have some of the cheapest energy prices in the country  (North Dakota, Kentucky, Nebraska, Missouri, Tennessee, Indiana, Oklahoma, and Alabama had the 4th, 5th, 6th, 7th, 9th, 14th, 15th, and 24th cheapest residential electricity prices in 2007) [DOE].

Another factor to consider is the square footage of the residences, which has also been continuously increasing over the last few decades [US Census].

This doesn’t mean that price per square foot is decreasing, however.  If we look at the median selling prices of new homes over the same time period (discounted to 2007 dollars), this is also increasing [DOE].

It’s no wonder that the current credit crisis started in the housing market.  We’re making bigger and bigger investments on bigger and bigger houses–and then paying energy bills to keep all the extra space running.  Per capita income may be increasing with GDP, but not as fast as home price is rising.  If we divide median selling prices of new homes by median income, the quotient is increasing over the years.

The question is: why do we need all this extra space when household size is decreasing?

Back in Blackle

This just in from Axil.  It’s a new Google search engine called “Blackle”.

blackle

The idea is that since the screen is mostly black. You use less energy while browsing. Makes sense to me.  I have no idea how much BS factor is involved.  I just like saying “Blackle”. Their spiel is pasted below. Or go here blackle spiel .

blackle1

Embodied energy and CO2 emitted in the production of some common items and building materials

Here we have a kilogram to kilogram comparison of embodied energy and carbon dioxide emissions during the production of some common items and building materials.  (The values for gasoline are not embodied energy/CO2 emissions of production, but energy and emissions produced by burning 1 kg of gas.)

Here we move on more specifically to building materials and put them in more recognizable building units.  For comparison, the energy and CO2 emitted in the production of the average American’s weekly food consumption and the energy and CO2 emitted by burning 1 gal of gas are provided.

Next, we compare wall-building materials.  Here we see some growing trade-offs in embodied energy and CO2 emissions, although distinct advantages can be seen in some building materials over others.  (CO2 emissions for Adobe unavailable.)

Finally, some insulating materials (adjusted to different thicknesses to achieve an R value of 10).  Here there are clear winners among the alternative insulating materials.  (Also notice the CO2 emissions differences between HFC-foamed and CO2-foamed polystyrene.)

Data from:

ASHEVILLE RENEWABLE ENERGY PROGRAM

Brownie Newman and Robin Cape have proposed an innovative financing model for residential renewable energy. Basically, the city would get people wanting to produce renewable energy on their property to sign on to the program. They’d then go get a loan for the full amount that everyone would need to install their systems. The City would then repay the loan by charging the program participants higher taxes for 20 years. Read more here: Asheville renewables