Casa Automatica - Aiming for Zero consumption in acclimatization

Hi there, I'm new here. Not sure if this make sense here. But for sure, you will tell if it's not. 

I'm Portuguese, I've 47 years old, 3 children, and spent the last 3,5 years of my life on a project I've called Casa Automatica.

The project started by being just an home control system, where I've tried to combined some security features, water control and home network, in a package, using and sharing an internet connection. The system is presented here

In the final stage of it's development, I've realized that water (greywaters) would be a great cooling system (evaporation). 

 I agree with Andrew McAfee. So, for a number of reasons irrelevant for this post, I've decided to developed a housing solution, target for the country side, that:

* could be reinstalled several times

* cheap and when buying it, when using it, and on equipment

* for all (with or without reduced mobility)

The results are presented here. Basically, in terms energy consumption on acclimatization: 

  • In the summer, (with 40º C), it doesn't need any air conditioning equipment
  • In winter, (with temperatures rounding +/- 5º C min), it consumes 1 eur / day in a T2 (75m2)

I found that air boxes are always relevant but, can even be more important when they are controllable. The house is transportable and that's good (after it's been installed is easy to sell, it can travel if you change your mind about the location, easy to produce). But this also means it has very little contact with the grown. As you all know, this means the summer is a challenge. A challenge that can be overcome by causing evaporation on the roof and by using and controlling a double façade that has no contact with the internal wall.

This means the house design is has to be a box (for now). In my mind that's fine, as long as it achieves the main goals.

The thermal results presented are good but can be greatly improved. They will be better next time, as the computer assumes control over internal air flow.

Let me share a design and a picture to make this post more attractive :)

3 modules

7 modules

Please comment, there are very few people (just 1, among my friends) that understand what I've being doing in the last 3,5 years :)

best regards

José Caramelo

Portugal, Odemira, Malavado

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Comment by jose caramelo on August 19, 2014 at 7:15am

Hi Hal, 

according to a online covertion tool : 118 ºF= 47.7 ºC, -10 ºF = -23.3 ºC. We don't have that variation. In my case, it's fair to say that, between the coast line and 100 km inside, we can see, an annual variation of -5ºC (23 ºF) and 40ºC (104 ºF). pls see averages here.

I've no idea on what's best for an large area / roof configuration as you show in the picture. In that situation, water does not solve your problem, mainly due to the wind, and the surface does not help either.

I find my roof configuration very helpful. in the summer works as a cooling device. In the winter does exactly the opposite, It enables the house to capture energy. you can see that happening in this graphic. The full study can be seen in the blog, (dentro = inside, fora = outside). 

the spikes you see in m1, and m4, are due to:

1. house orientation (sun rise orientation)

2. large door and sensor position

The house as 45m2. between m2 and m3, i've added just 765w. I'm sure of the added energy as I used lamps as these :)


Comment by Tom Mallard on August 18, 2014 at 9:00pm

Right José, my post was more for someone with an existing home with siding to see what a change it can have thermally to move the siding off of the sheathing. Your system is far better by having no conduction paths, the thermal models show this, the standard wall saw 4.1C at the gauge, furred over a stud was 3.4C, furred between studs only 1.1C.

It's really important to keep the conduction path to the studs cut off from moving heat.

Comment by Hal Skinner on August 18, 2014 at 8:39pm

Hi again Jose.

How does your weather there compare to, lets say, Western Texas where it reaches 118 degrees in the summer and minus 10 degrees in the winter.  We coated the flat roof of a 200,000 sq ft egg production facility there.  Flat metal roof, metal walls.  Roof was white from the factory and the walls were a light yellowish-tan from the factory.  We cut their cooling requirements by 50%.

If you are fighting heat gain, coating the roof and exterior walls with our RCC, you will drop the btu requirements by 50%.  You can look on my group 'Radiant Control Coatings' and at all the discussions and see why I am very confident  in making that statement.

We ALWAYS drop it by 50%.  ALWAYS.

Comment by jose caramelo on August 18, 2014 at 7:58pm


thank you all for you comments and indications to other techniques. I'll to address all you comments, proving information here, or with points to my blog.

Regarding coating, Hal, I haven't tried it yet. But my guess is that is not enough for the Mediterranean weather pattern. Evaporation is far more powerful. You need to have the conditions in place, among others, the roof has to be flat. But, what I can say is that, this is my cooling mechanism. Its able to release energy, a lot. Just imagine you leaving a poor with wind. 

Tom, regarding the furring, I have one, simple and cheap, but most important, I have a an empty space all around the house. there no contact (far less than 1%) between the façade and the internal wall. With air box, you can suck the hot air in the summer (from the top) with this:

and capping it in the winter. As simple as that. You change the walls beaver from summer to winter.

Ben, please follow the links to my blog. I'm not fluent in english, as for sure, you have noticed.

From what i've seen from Passive houses techniques, they enable architects to maintain the design they have in mind. I've went futher, The house was design with 3 goals in mind:

* transportability

* efficiency

* price.

I assume there is a market for that. Maybe I'm wrong, I'm not finding the selling process easy. People are very concerned about the moments they spend outside contemplating the house, and less about the money will have to spend buying and using it. However the paradigm will change. that's what Andrew McAfee explains brilliantly. I worked in software for 15 years, you haven't seen nothing yet

thank you all, 


Comment by Hal Skinner on August 18, 2014 at 1:04pm

Hi Jose,

We have been applying an RCC (Radiant Control Coating) on, in, under and around mobile homes for 30 years.

Check out the discussion on mobile homes at this link

Hal Skinner

Comment by Tom Mallard on August 18, 2014 at 11:31am

Nice work. Related to the double wall is a simple upgrade that can be made by using furring under the siding on a building to reduce conduction, the standard wall heats the thermometer to 4.1C, with furring 1.1C for a run of 400-minutes, this is 1/4th the heat transfer and easy to see:

Comment by Ben Jacobs on August 18, 2014 at 11:13am

Hi Jose,

With the limited information that you provide and your photo and diagram, I would think that your project home has a lot in common with a "Passive House" design home.

Below is some information that I have gathered on how the "Passive House" design compares to other models of homes in North Carolina.

I think that leaders and professionals in the work of Home Energy Efficiency should be more proactive in sharing information at the regional level about real world experience of homeowners with energy use in their homes. I think that proactive leaders at the state level should develop online resources that can be easily accessed by others to see how their homes perform. I think it would help homeowners and others to track their use if they knew well how other homes with similar characteristics performed.

For example below is information that I think could be easily compiled and shared at a state by state level, or region by region level. I think this information would be much more valuable to homeowners interested in home energy efficiency than the US Dept. of Energy, Home Energy Yardstick measure.

Below is a information that I have gathered specific to Eastern North Carolina and provides a FY 2013 comparison of Energy Use by different models of homes. The comparison models are:

Comparison of Energy Use by different models of homes

Home measure 1800 square feet,
Home has 3 occupants, all electric, compact/ranch design
Home has appliances that meet 2009 Energy Star requirements,
residents follow regular home energy efficiency practices)
Home is located in eastern North Carolina

Electricity price/ rate at $0.11 per kWh

Design/Standards : 2009 Passive House design
Total Annual Home Energy Bill: $750
Energy Cost per square foot: $0.42 /ft2
Blower Door Test Rating : 0.6 ACH50

Design/Standards : 2009 Energy Star
Total Annual Home Energy Bill: $1,300
Energy Cost per square foot: $0.72
Blower Door Test Rating : 6 ACH50

Design/Standards : 2012 Energy Efficient Retrofit
of home built in 1990
Total Annual Home Energy Bill: $1,700
Energy Cost per square foot: $0.94
Blower Door Test Rating : 9 ACH50


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