How Heating Has and Will Change

Fire place heatingThe evolution of heating the home in history has done a complete U-turn in recent years.  The increasingly popular Solar Passive and renewable energy heating techniques have been around since ancient times and are making a return in modern construction.

Heating in the 19th Century

In the early 1900’s, much like today, dual purpose devices were quite common.  Ovens doubled up as heaters, and fireplaces were used in each room.  It was a time when we believed in the meaning of the word economics.  The use of a wood stove was preferred because renewable wood fuel was free for the cutting, while kerosene had to be purchased with limited cash. In winter, the kitchen stove would be the first to be lit, since it could be used for both heating and cooking. The fireplaces in the connecting rooms would be only used as needed.

The key beneficial features of the home dynamics were:

  • Radiant heat
  • Less pressure equates to less air leakage (no fans are moving around air)
  • More ventilation (for health and safety)
  • Use of a renewable resource
  • No reliance on technology to be comfortable

Drawbacks:

  • Uncontrolled ventilation resulting in air leakage
  • Not scalable for populated areas, because burning wood can be more polluting than coal, and if you can’t replace the trees fast enough, it’s also not renewable
  • Burning wood produces CO2, CO, and particulate smoke
  • Uninsulated buildings meant energy radiating inside the house would conduct through the building envelope.

History of heatingHeating in the 20th Century

The gold and glitter age of gas, oil, and coal pushed technology toward combustion, combustion and even more combustion.  It was a time when over-consumption became economic.  With cheap energy at our doorstep, the pressures inside the building envelope are raised with air handlers and other air conditioning devices.  The building envelope is left in complete disarray, pushing warm air through gaps in downlights or evaporative cooling ducts and conducting heat through the building via conductive materials. This occurred across uninsulated walls, aluminium windows with single glazed glass, box type air conditioners or recessed lighting.

The key beneficial features of the home dynamics are:

  • Scalable for highly populated areas, while energy is cheap
  • More ventilation (for health and safety)
  • Comfortable living and the whole home is kept warm

Drawbacks:

  • Not scalable with expensive energy
  • Uninsulated or poorly insulated buildings means energy radiating inside the house would conduct through the building envelope.
  • Uncontrolled ventilation resulting in air leakage
  • High pressure (fans move warm air around everywhere) aggravates air leakage through the envelope and leaky duct work.
  • Use of fossil fuels
  • Reliance on technology, maintenance, and energy to be comfortable
  • Mould can grow around window frames and inside wall cavities.
  • The building envelope is complicated due to separate duct systems for heating and cooling.  Evaporative cooling ducts become chimneys for losing heat that naturally rises.

Solar Passive design heatingHeating in the 21st Century

Back to simplicity…  Solar Passive Design & Passive House Design.

The techniques of passive solar building design were invented and put into practice thousands of years ago by necessity, before the invention of mechanical heating.  The combination of passive solar design and modern insulative building materials with airtight construction techniques comes close to, or achieving Passive House design (Passivhaus), This means the energy required to keep a home warm becomes manageable with “NO” or a small amount of energy input.  Forced ventilation systems recover heat from the air exiting and entering the home, ensuring a high level of air quality with minimal energy loss.  Passive house design also eliminates, condensation, mould, and allergens due to forced air ventilation filtration.

The key beneficial features of the home dynamics are:

  • Scalable for highly populated areas
  • Comfortable living.  The whole home is kept warm
  • More controlled ventilation (for health and safety)
  • Better quality air and less CO2 content
  • Less Pressure equates to less air leakage (smaller fans are moving around air, specifically for ventilation only)
  • Air tight construction (Controlled ventilation with energy recovery)
  • Use of a renewable resource (for heating and potentially cooling)
  • No carbon emissions

Drawbacks:

  • ZERO drawbacks in an Australian or New Zealand climate

As much as things look quite different now compared to the 19th century, we are starting to understand economics again after being blinded by quick fixes dependent on high carbon and electricity use.

Go energy-lite, Ventilate right, and then go air tight.

by John Konstantakopoulos