The best air conditioning system for my house

The air conditioning systems bring simultaneously competing ideas on the top of our mind:

• comfort during hot seasons
• power hungry systems
• luxury amenities
• no so much required in our mild climates
• dangerous for health (allergies, colds, dry throat, etc.)

The classical systems utilize fans and air compressors in order to cool the inside air temperature. The drawbacks are well identified above as well as the noise generated which may disturb your quiet neighborhood.
In order to reduce the electrical expense, one may instal photovoltaic solar panels, as per the clean power show, session #4.

A second option consists in using the heating floor system in a reverse mode becoming a cooling floor. The feedbacks reveal mitigated impressions on its real cooling efficiency. Besides, its is often subjected to condensation or cracks since it requires an accurate dimensioning and installation.
It should be noticed that geothermal installations usually provide such ability to reverse heat and cold.

A last option but not the least, is brought by the canadian dwell (combined to a centralized mechanical ventilation). In such a configuration, the outside air is simply cooled down by the outside ground temperature, without any drawbacks such as dry throat or allergy.
It should be noticed that such a system provides a reversed heating function during winter.

Now, what choice could you make ? Well, basically, it depends on your location as well as on a very important factor: the isolation performance (see my previous post on that topic).

• For hot climate conditions, the first option is a must, as well as for house having poor isolation performance. It does not prevent you from spending efforts and money on that last point.
  
  
• The second option (cooling floor) is rather dependent from your heating system choice. Indeed, you will always install a heating floor because of its nice heating performances, and by the way, you may find beneficial to use the same floor as a cooling system.
  
  
• The last option (canadian dwell) may suffice in many configurations, provided that you applied simultaneously a good isolation performance.
  In my opinion, compared to the other options, this is definitely the best area where to spend you money !
  

The Clean Power Show

Very nice concept from the subject blog where you can see live interviews on various topics mainly around solar energy.

http://www.cleanpowershow.com/

In particular I found interesting the post #4.

I just would like some more new posts.

At least it gives me some ideas... keep you posted !

Individual wind power in town: is it possible ?

The answer is YES !

In particular I would like to draw your attention on a specific design: the vertical architecture (see illustration here from windside)

The vertical wind mill brings the following benefits:

• silent
• no risk to loose a spoiler
• no need for a work permit
• not sensitive to pollution
• support even stronger winds compared to the classical wind fans
  

All the above benefits concur to be the ideal wind energy for downtown configurations where field yards are rather small and where the neighbourhood is close.

Beyond that architecture, I would find interesting to have a combined solution using vertical wind mills and solar panels in order to cover both bad weather and good weather conditions, and therefore maximize the power production.

Should you know any reseller of such a kit, please let me know !

Humidity control: a key new concept in the house

Talking back about the isolation tips given before in that blog, you may realize that we have been looking for a complete isolation between the outside air and the inside air.

Further illustrating that concept, you may take a look at the pressure testing (so called blower test) required by the passiv haus institut certification.

Now, once isolated, your house behaves like a thermal container and the humidity generated inside is now contained too (humidity generated by the wet rooms like bathrooms, kitchen, etc. or generated by the human breathing). Without any control, such a humidity concentration may become a source of bad feelings, a source of moistures on the wall, and worse, a source of diseases (allergies, etc).

The right humidity concentration should be within the 40%-60% range.

Fortunatelly, solutions are available:

• Centralized Mechanical Ventilations (Simple or double flux)
• Canadian well
• Humidity regulator controlling the ventilation speeds.

Actually you need to implement the above three solutions together in order to maximize the ventilation efficiency whilst reducing the waste of inside heating or cooling effort. The canadian well brings a significant contribution to that.

By the way I strongly believe that the Ventilation Simple Flux combined with the Canadian Well is good enough to fullfil the target. In other words, the Ventilation Double Flux generates useless extra-cost in such a configuration.

Solar Energy: Forbes is having a full coverage on this

Check this out: it's on Forbes.com

To summarize, the solar industry is quite optimistic when looking at the future shortages in gas. However, that economy remains fairly dependent from subsidizations and today, the price per Watt produced remains high.

Dramatic discounts are expected from the mass-market volumes forecasts. Meanwhile, the price of silicon raw material is also raising due to market pressure from various high demanding industries.

I liked the interactive maps and the video webcasts. Enjoy !

Isolation: the fundamental component

Before talking about clean energies to be used in your house, anyone should pay extreme attention to the isolation performance.

Indeed most of our house have been designed with poor isolation performance and new initiatives are popping up to work that around such as bioclimatic house, or the passiv haus institut, etc.
The latter evoques the possibility to give-up any heating system, or reduce it to a very small unit.

To summarize my thoughts around that topic, I would advise the following best practices:

A good isolation means a complete separation between outside and inside the house. The best isolation performance is given by non-moving air. In order to deliver a global efficiency, the following components should be handled with care:

• the external walls
• the roof
• the floors
• the external doors and windows using double or triple glas thickness.
  
• thermal break of the balcony & terrace attachments to the house
• protection of the house from the dominant winds
• the ground fundations
  

Based on my current understanding, I would recommend to proceed with the following techniques:

• The external walls should be isolated along with 3 layers.
  Layer 1, in touch with external air should be rather protective from rain and shocks. I would recommend the use of wood or stone.
  Layer 2 (inner layer) should be made of thermal isolating material (polystyrene, woodwool, rockwool, etc.). You can qualify the thermal performance using basic technique: this should be warm when touched...
  Layer 3 is facing the internal air of the house. This layer should support the house structure, including the floors & ceilings, and should provide high thermal inertia, with good thermal infrared performance. You can qualify such material with heavy weight concrete walls (cellular, high density, etc.), or, even better, with bricks (monomur, etc).
  
  The humidity control issue should not be missed here. I invite you to read my next posts on it.
  
  
• The ground fundations have to be well isolated too. New techniques have been explored by our friends building a passive house in Nice (French Riviera). The most convincing demo is given by the Isoquick german company.
  
  
• Regarding the roof isolation, I would be very cautious in front of those new thin layer materials. Provided that the non-moving air is the best isolator, the thicker the better... I would rather recommend either the use of rockwool, or woodwool, or even polystyrene (less bio-ethical).
  

English version

Hi,

After a few days playing with the subject in my native language on GreenPowerHouse, I just figured out that my audience may be larger whilst offering the translation in English.

That time has come true. (yeah !)

Before going ahead, let's be clear on the purpose here: the Green Power House is all about providing the aggregation and compilation of the best practices around the clean energy technologies available for your house.

I am a private citizen having an engineering background, living in the Paris Area (France), and willing to get prepared for my next brand new house set to be as clean and power efficient as possible.