Passivhaus

Introduction

Passivhaus is one of the terms out there in eco-green-sustaintable building land. It may look like its spelled wrong but that’s because its originally from Germany. It represents a very strict and high standard of energy efficiency in a building. It isn’t (yet) an official requirement or standard but it is gathering momentum as an unspoken standard.

There are three complementary core ideas behind the idea of a Passivhaus:

  1. Complete and thorough thermal insulation of the house which prevents conductivity of heat from the inside-out or the outside-in.
  2. Complete air-tightness which prevents exchange of heat through air leaks (windows, doors, pipes, chimneys … every opening needs to be sealed!).
  3. An efficient ventilation system that both exchanges air (from the outside and the otherwise airtight house) and does so without losing heat.

This is one of those images that is better then a thousand words. The apartment building on the left is standard/traditional building while the apartment building on the right is built according to the Passivhaus standard. That’s the bottom line of Passivhaus – keeping the heat from escaping means you need to expend less energy to heat the inside.

Extreme!?

I have come across Passivhaus numerous times in recent weeks and my recurring personal impression is that it is too extreme:

  • It seems like more of an academic indulgence then a practical construction practice.
  • It’s objective and success is measured in a single number – the amount of energy needed to heat a square-meter of space.
  • It demands rigorous builing disciplines which require uncompromised excellence in construction.
  • It demands the use of specialized insulation materials which can be expensive (especially if you consider the ecological foot-print involved in manufacturing them).
  • It creates a house that demands constant attention, maintenance and proper use by its residents (every window opened and every hole drilled in the wall is a potential energy hazard).

All of which results in a delicately balanced system: if it isn’t absolutely sealed, perfectly ventilated by a carefully installed system and properly used it just won’t work. There is no room for error. This maybe OK in a scientific experiment but not so for life, nature and people.

In any case it doesn’t feel right for us: we have a limited budget, average construction capabilities, standard building materials, etc. We are going to do the best that we can with what we have. It’s an 80/20 kind of thing – where 20% of the effort takes you 80% of the way you need to go and it would take another 80% of effort to go the rest of the way. We’re aiming for a good middleground – pushing the limits of what we have – but that, by definition, is not enough to go for 100%. Passivhaus is uncompromising, but we live in a reality which demands compromise.

“A passivehouse is cost-effective when the combined capitalized costs (construction, including design and installed equipment, plus operating costs for 30 years) do not exceed those of an average new home.”

Source: PassiveHouse.com

I am hesitant to relate to this statement as that may give it unwarranted legitimacy –  cost is just too narrow a perspective to view ecological housing. But if I do meet it head on, as is, I would say that it sets its sights much too low. I hope to build a house where the combined capitalized costs are much lower then those of a new average home (whatever that is). I also hope to build a house who’s qualitative effects (both for us and others) far outway it’s economic effects.

Maybe Passivhaus is, for the time being, a high-end building experiment? Maybe in time it will spawn accessible, affordable and feasible techniques, solutions, technologies, practices … that can become a defacto standard that simply makes sense to follow? For now, it is out of touch with us and our needs.

Humidity

Having said all that exploring Passivhaus has brought to my attention a factor I had not taken into consideration in all of my energy research: Indoor Air Quality. I have been following a very basic intuition: “generate heat” in trying to solve a problem we’ve been having for many winters: “being cold”. Most of my attention has been on how to preserve and generate heat (space and water) effectively.

I had not given any thought to one of the central themes of Passivhaus: quality of air. Quality of air (assuming there is good ventilation) is strongly effected by humidity … and humidity effects the overal experience of temperature … cold is much colder when humidity is too low and heat is much hotter when humidity is too high. I have experienced the effects of humidity in warm and cold temperatures in Israel and I have seen it (as accumulated moisture and mildew) in almost all Romanian homes I have visited.

I don’t know yet enough about ventillation and humidity.

Hemp

One of the much praised qualities of hemp masonry is it’s breathability. It seems to have a natural tendency to absorb and expel unneeded moisture. I don’t yet have enough information on the overall effects of hemp on moisture, ventilation or quality of air indoors – but I do have a good feeling about the effects of hemp!

Resources

Following are some of the resources I came across and consumed in trying to understand Passivhaus:

Other Power + Costs

I came across this really useful website on alternative energy. It looks like it’s been gathering dust  and it’s design is somewhat outdated but it’s information seems timeless. Whether you want to go about doing it yourself or to use commercial solutions – their website is a great resource of information – check out Other Power.

Through their website I found two other useful links:

  • One is the US Department of Energy – though the information is presented a USA context – some of it is global and useful. Specifically I found the area on eletrciticy to have useful overview explanations of eletricity generating systems and their components.
  • The other is Bergey – a manufaturer of products and systems. Specifically their Packages pages provides tangible understanding of (a) the potentially high costs of commercial systems and (b) the relative costs of components that are needed to put together an entire working system.

Here is an example of a system that delivers: 400 – 1,500 Kilowatt-hours (kWh’s) per month (depending on wind resource), 24 hours to over a week of back-up power (depending on load and wind).

7.5 kW BWC Excel-R/48 w/VCS-10 $26,870
100ft. guyded latice tower kit $14,145
Tower wiring kit $1,615
DC Power Center, 9 circuit $850
84 kWh, 5 String, Battery Bank $15,000
7.2 kW Inverter system $6,676
Total costs $65,156

The most expensive elements are the turbine itself, the tower and the batteries. The price of the batteries was informative to me because they are needed regardless of how you generate electricity (wind, solar, hydro… ).

Information on Harvesting Hemp – Part 1

Inspiration

I am currently living with an inspiring notion that we will (1) be able to grow the hemp needed to build our future home and (2) that we will have enough land to grow a houses-worth of hemp every year so that someone else will be able to do the same.

Introduction

Though I have to say that the more I explore the world of Hemp the more doubts about this being a feasible goal. At the end of this post you will find some links and PDF’s I read and that led to my current understanding.

Hemp seems to be a relatively easy crop to grow. It’s strong, it doesn’t require pesticides, it grows pretty fast (~4 months) and it even renews the land in which it is grown. The more substantial challenge is harvesting and processing it.

Three Parts of Hemp

There are three parts to the hemp plant – each with it’s own uses:

  1. The seeds can be used for all kinds of food products, oils and other medicinal by-products.
  2. The fibers have all kinds of industrial uses (from clothes to cars) – they are the middle layers of the stalk covered by a thin protective layer.
  3. The hurd – the wooden core that is left over after the fibers have been extracted – which is the part popularly used (together with lime) for construction (although I have come across information that indicates that it is possible to use the fibers and curd together for construction – which means that they don’t need to be separated).

Some Hemp Harvesting Facts

  1. Seeds and stalk don’t mature together – they are (or at least should be) harvested at different times. Both the seeds and the fibers have (different) optimal times for harvesting – beyond which both lose some of the potency and qualities.
  2. The seeds don’t mature all at once – they tend to mature in two cycles. Harvesting time is when you think you can harvest the most mature crop (when some of the seeds may have decayed or lost their potency and others still not quite matured).
  3. Hemp is a tough plant – so you need resilient and strong harvesting tools. The strength of the fiber means it’s hard to cut down and the length of the stalk means it will catch on to and jam any moving part it finds (for example – combine machinery) – which means that you either need powerful harvesting machines – or that harvesting may be slow and tedious.
  4. Hemp is a tall plant (much taller then wheat or barley) – which means you need harvesting equipment that can reach up high.
  5. When the stalk is cut, it is useful to do it in such a way that it is then easy to collect into bales – if I understood correctly what this means is that the harvester needs to leave the cut stalks uniformly oriented on the ground.
  6. The stalks should be cut as long as possible – long fibers are generally better and more useful then shorter ones.
  7. It is possible to harvest both seed and stalk. Seeds go first (duh!) – but then you not only need tall harvesting equipment but it also needs to be sharp and fast spinning – so that the stalk is cut cleanly – leaving long fibers in tact.
  8. The primary processing for seeds is removing them from their shells – I still don’t have information on how that is done.
  9. The primary processing for stalk is separating the fibers from the wooden sheathe (this is called “decortication”- whichI am guessing comes from the idea of removing the core and, apparently, originates from a medical surgical process of separation). There are numerous methods for this – but generally they seem to be divided in two: industrial processes and organic/natural processes. I am less interested in the industrial aspect so I focused a bit more on the natural processes. Apparently the idea is to use water to cause decomposition of a kind of “glue” that keeps the fiber and curd attached. Usually natural dampness like dew will do the trick. You need to keep an eye out on the crop until separation begins – then you need to let it dry for a few days. I am not yet clear on all the details of this process.

All these facts seem to eminate from an industrial/financial view point. They are focused on creating optimal yields and financial returns. If harvesting and processing hemp can only be done using heavy and expensive machinery – that means that growing just a few acres or a hectare of hemp isn’t feasible.  I was somewhat discouraged by this. But …

Since hemp has been grown for hundreds of years (if not thousands) I am sure there is much knowledge on how to do it on a smaller scale – for home needs but I haven’t been able to find any information on this yet. It may require more manual labour but I am confident it is possible. Our needs are humble – maybe to build another small structure for meditation, enough seeds for eating, making oils … the needs of a small family.

I’ll continue to look for more home-oriented information on this – I promise to share it here when I do find it.

Resources and Further Reading

Links:

PDF’s:

An Imaginary(?) Intergrated Heating System

This morning I walked into a cool Yoga room (we usually have in our house one room which is dedicated to Yoga, Meditation, etc.). It’s the coolest of the rooms in the apartment because it’s a corner room and extremely exposed to the elements (and probably not well insulated). This launched us into a conversation about options to optimize the heat in the apartment and that conversation led us into a wider exploration of heating solutions.

Local vs. Network

One quality of a heating solution is whether it is local to the space in which it is installed and operating or whether it effects other spaces in the house. For example:

  • A local system would be an electric heater that effects primarily the space in which it is activated.
  • A network system is the central gas heater installed in our rented apartment – it heats up water to  a set temperature and that water flows through a network of pipes that lead into radiators ain all the rooms of the apartment. A single mobile wireless thermostat can be placed in any room and it trigger the central heater into operation. If it is placed in a cold room it activates the central heater until the designated temperature is reached – but it’s effect is felt everywhere as other rooms heat up as well (potentially beyond the designated temperature – as is the case with the poorly insulated Yoga room).

Energy Source

Any heating system requires an energy source. These can be gas,electric, fire wood, solar, infrared, geothermal … and there may be others.

The preferred source can be a function of:

  • Availability – gas pipelines are an established infrastructure in Romanian cities, less so in villages where you have to rely on refillable pressured-gas containers. There are relatively new technologies that make it possible to manufacture gas from animal feces (we hope to find more information on this).
  • Price
  • Ecological effects (we don’t know enough about this yet)

Function

To the best of our current knowledge there are three application for heat in a home:

  1. Environmental heat.
  2. Hot water.
  3. Cooking

Efficiency

We are not experts on heat and efficiency but common-sense indicates that efficiency is worth noting and can potentially be optimized. Some examples:

  1. When the water heating source is far from the hot water faucet – there is some waster of flowing water until water is heated and reaches the faucet.
  2. When the faucet is opened briefly (for example – rinsing the hands while cooking) and the faucet demands hot water – water doesn’t arrive in time but the heater is activated pointlessly – a pure waste of energy.
  3. Pipes that connect radiators to a central heating system also radiate heat – probably not as effectively as the radiator.

Requirements of an Ideal Heating System

An ideal heating system for us would be a system that:

  • Can effectively heat any single space in the house (local)
  • Can effectively heat other spaces in the house (network).
  • Relies on an available and affordable (ideally – self generated) energy source.
  • Is multi-functional so that a single heat source can be utilized for other needs. For example, if cooking in the kitchen, that same energy can used to heat the kitchen and optionally other rooms in the house.
  • Can be targeted effectively depending on the need. For example, if cooking and there is no need to heat other rooms, do not let hot water escape unnecessaritly to other radiators in the house.

An Imaginary(?) Integrated Heating System

Please note:

  1. This potential system (imaginary is there because we have not yet encountered such a system) is designed for a village house in Romania. So if you live in a different climate with different needs it may not be ideal for you.
  2. It is based on our common-sense understanding of how heating system work and our needs.
  3. It is based on an aspiration to live in a self-sustaining how – which means as independent as possible in everything including its energy sources.

Heat Sources

  1. The primary heat source is fire wood. Fire-places are installed in every room which we want to be able to heat individually. Ideally this is an every room – though there can be joint-fire-places that are installed on shared walls.
  2. A small gas-based central heater is used for hot water when only hot water is needed or during summer months when there is no need for environmental heating.
  3. Solar panels are used for an alternative hot water source during sunny days.

Network

  1. All of the rooms (except maybe the living-room?) are equipped with water-based radiators that are hooked into a central house-wide network.
  2. All of the hot-water faucets are connected to a separate (from the central network) one-way (no returning water) hot-water channel.
  3. Each of the fire-places is:
    • Connected to (installed with?) an adjacent boiler which is connected to the central heating pipe-network.
    • Connected to the central house network with an open-close control mechanism.
    • Connected to the hot-water channgel with an open-close control mechanism.
  4. A gas-based central heater is connected to the hot-water channel.
  5. A solar panel water heating system is connected with open-close controls to both the hot-water and central house network.

What this creates is an effective heating system in which:

  1. Any of the fire-places can optionally take the role of a central heating system.
  2. The fire-places can work together for greater power and efficiency when they are used for heating.
  3. Alternative heating sources can be hooked up to complement and support the system.

Such an ideal system is probably prohibitive to install (lots of piping, numerous boilers, etc.). A specific house-design can probably help to whittle the size of the system down by reducing the number of elements. But more importantly – with a good and accessible infrastructure in place it may be possible to gradually expand the system as needed or as if financially possible. It feels like one of those cases where a bit more thinking and design can lead to a better system with very little overhead expenses.

Are we crazy or does this sound feasible to you?