heat pumps - SprintBio - Distibutors of environmentally friendly boilers, burners and heat pumps

Under current UK government legislation all new-build homes must be zero-carbon after 2016. However, some of the major builders are trying to get a head-start on this deadline and have begun developing designs and prototypes already.

One such company is Barratt Developments - one of the UK’s largest firms - which this week unveiled designs for what will become the country’s first zero-carbon house built by a volume builder. The first examples of these homes will be available from 2011, in a 200 unit batch at the site of Hanham Hall hospital, near to Bristol.

All of this sounds great, except for one snag - the cost of the homes. Though Barratt have not specified the exact value, their chief executive, Mark Clare, has said that it will be ‘difficult to reduce the cost of the current prototype to commercial levels’.

Now, it’s all very well having lots of zero-carbon homes, but not so great if they all lie empty because nobody can afford to buy one… The question is; what can be done to avoid this situation from developing?

Well the simple fact is that such projects will require quite a degree of government assistance to succeed quickly. No doubt Barratt and other developers will do what they can do drive building costs down - but ultimately there is only so far this can be taken before we are left with a zero-carbon, but ugly and low quality home that nobody wants to live in.

In the first few years after 2016 (maybe even before) it will be crucial that the government subsidises the cost of such homes so that they can compete with the older properties on the market. Some measures have already been introduced, such as a stamp duty waiver until 2012 on zero-carbon homes worth over £500,000 (homes under that value are eligible for a £15,000 stamp duty discount).

This is a start - but hopefully only the beginning of a series of similar moves.

Barratt’s prototype for example utilises solar panels, rain-water harvesting, and an air source heat pump. It is these features, along with its super-insulation and triple-glazed windows, that have earned it the best possible energy use rating of grade 6 (signifying a completely zero-carbon home). Perhaps the industry sectors producing this technology could do with a few tax cuts, or incentives in return for helping reduce costs.

It is true that a zero-carbon home will face only very minimal running costs and hence a case for the higher asking price could be made on these grounds. The problem is that, if would-be buyers cannot even secure a mortgage for the house, the rest becomes irrelevant.

This is where banks have a part to play - by introducing a different mortgage option for buyers purchasing such homes they could be instrumental in the success of zero-carbon housing. With the current credit problems many banks have reigned in their mortgage options of late - but those buying a zero-carbon home in the future will have a greater ability to repay a big mortgage - due to the lack of gas and electricity bills. A bigger loan could therefore be repaid in the same time as a smaller one on a non grade 6 property.

There are many other potential measures currently being discussed - but the main point is that the government needs to seriously consider further legislation (or funding for buyer-assistance schemes) in order to ensure that the initial mandate of zero-carbon by 2016 is the success it has the potential to be. If this can be effectively managed then the (positive) consequences could be far reaching indeed - from the inherent environmental benefits, to reducing the cost (while raising the standard) of living in the UK. Let’s hope those involved can get it right, for we all stand to reap the rewards of this effort.

(A detailed image of Barratt’s design can be found here).

Dejan Levi

A three-bedroom home with a basement and hardwood floors soon will be on the market for those looking to move to a quiet subdivision in Jackson Township. What makes this $296,000 house unique is not merely that it was built using energy-efficient and environment friendly techniques.

Rather, it’s that a group of Chesterton High School students built it from scratch, starting with the blueprint.

“It’s a full year … (the students) are responsible for a lot of things,” said Jeff Larson, instructor of the school’s vocational building-trades class.

On Wednesday, about a dozen vocational building-trades students were busy at the site in High Meadows West, making final touches like installing toilets, tiles and sinks.

A school bus takes the students to the house,which has more than 2,000 square feet of living space.

“It beats being in the classroom,” said Jeff Wilkinson, 18, of Chesterton.

The class received a loan from the Kankakee Valley REMC utility, which has a partnership with the Duneland school district.

After the house, which is in REMC’s service area, is sold, the money is paid back to the utility for the amount it loaned.

Anything above the loan amount goes to the school, said Amanda Leek, spokeswoman for the utility.

The idea began with REMC’s power supplier Touchstone Energy with the purpose of educating the next generation of builders, Leek said.

The construction took two years with textbook schoolwork in the classroom.

“I think people looking for homes don’t often understand what the overall concept of energy efficiency is, that it incorporates a lot of things,” Larson said.

From using recycled materials for insulation to fluorescent lighting throughout the house, the students learned about the variety of environment-friendly options.

They also installed an air source heat pump that uses electricity, not natural gas, and meticulously sealed and caulked to ward off outdoor drafts.

“It gives you a better understanding of what goes into building (a home), said Brian Katzmarek, 18, of Chesterton.

“It helps you learn how to fix things around your own home,” said Rashad Williams, 18, of Valparaiso.

Most of the students began the project last year after they designed a blueprint of the home, considering factors such as what an average family would move into and the marketability.

Before getting their hands dirty, students review safety issues and plan out the project just as if they were professional builders.

They survey areas, select a site and figure out what has to be done not to disturb the environment.

They also talk to subcontractors to learn about the processes the professionals go through.

The students say they are likely to seek a career in building construction.

“We’re just thankful that they actually give us classes like this,” said Chad Passarelli, 18, of Porter.

A major boost in the effectiveness of a material that transforms waste heat into electricity could significantly boost energy efficiency in anything from air conditioners to car engines. It is the first major improvement in such “thermoelectric” materials in 50 years, say researchers.

Thermoelectric materials can also work in reverse to convert electricity into differences in temperature, allowing cooling without pipes, pumps or coolants.

Since the 1950s, engineers have used a semiconductor alloy called bismuth antimony telluride in niche applications, such as solid state cooling for precision medical equipment. But although it is the best material around for the job, the alloy is far from efficient. The new efficiency boost could see thermoelectric materials used in many more areas.

Rip it up and start again

The dramatic 40% boost is relatively simple to achieve. Grinding bismuth antimony telluride into fine particles and then pressing it back together again using heat transforms its thermoelectric properties, according to researchers from Massachusetts Institute of Technology (MIT) and Boston College, both Boston, US.

Sticking the nanoscale particles back together increased the alloy’s peak figure of merit, a term used to measure metals’ relative thermodynamic performance, by 40% from 1.0 to 1.4.

The researchers say the jump happens because the reincarnated alloy has a finer-grained crystalline structure. The new structure offers greater resistance to the quantum vibrations called phonons that transport heat within solids, making it a better thermal insulator.

This is crucial because thermoelectric materials work by maintaining differences in temperature while letting electricity flow freely. If less of the incoming heat can escape through heat conduction, more will be used to drive electrons, and the material will be more efficient.

Heat hurdles

For phonons carrying heat, having more crystal grains to cross “is like the difference between running the 100-metre dash and running the same distance with hurdles every 10 metres,” says study author Zhifeng Ren.

Prior, unsuccessful, attempts to shrink the crystal structure of thermoelectric alloys tried to build the new materials from scratch, layer by layer, in an expensive method called thin-film deposition.

“That’s more like artists making fine art,” Ren says. “Our [process] is like a copy machine, making much larger quantities much faster.”