People in the market for new homes usually have their eyes on different key features during the search for their potential perfect abodes. Some desire a convenient location, some look for luxurious spaciousness, some seek a lush garden and others are after all of those things at once -- or other elements entirely.
One aspect that generally doesn't play a huge part in the home buying decision is how the house functions in terms of energy efficiency. Not to underscore the importance of this characteristic -- after all, you'll most likely be getting monthly reminders judging your home's heating and cooling capabilities the entire length of your ownership -- it's just that with so many other thoughts swimming through the head of someone in the market for a home, energy aptitude isn't often a deal-breaker, or a deal-closer for that matter.
But in terms of other homebuyers, that's definitely not the case. For them, one of the utmost important aspects of the purchase of a new home is how efficiently it performs -- some people even build a home expressly to spare themselves the monthly joy of power bills. One of the ways they can go about achieving this energy independence is to build a home using the patented Enertia Building System. The system works by taking advantage of age-old building concepts along with innovative new techniques, and while it might not completely erase the power bills, it can definitely ease them down into a more reasonable range.
The basis of the concept centers around timber -- and these aren't spindly two-by-fours. Unlike conventional modern homes, Enertia houses are massive structures built entirely of wood, and this wood acts in an interesting fashion. On the next page, we'll take a look at the components of a house built using the Enertia Building System and see how everything comes together.
The Components of an Enertia Home
Before we dive into how the Enertia Building System (EBS) actually operates, let's take a closer look at some of the key components these homes encompass:
Southern yellow pine: Although other types of timber can be used, southern yellow pine is the hallmark tree of EBS construction. That's because according to Enertia Building System's president Michael Sykes, it's a fast-growing tree that's loaded with resin and other properties, which make it excellent at absorbing energy and slowly releasing it over a period of several hours. It can also be augmented to have an even greater thermal mass -- the capacity of heat it can absorb -- by applying various patented treatments. This means that instead of attempting to deal with heat by utilizing the air enclosed within a house, the house itself holds and releases the thermal energy necessary to keep the temperature in check.
The primary space: This is the main living area of the homes. All the domicile mainstays like bedrooms, kitchens and living rooms of EBS houses are contained within the primary living space, which is alternately called the inner shell. The use of wood isn't limited to the outside of the house; you'll find it here too.
The dynamic envelope: Also known as the buffer zone, the dynamic envelope surrounds the entire inner shell and is encased by the home's outer shell. This is where the magic happens; consisting of the basement, southern sun space, attic and northern double wall, the dynamic envelope contains a solar-powered convection current, which carries hot and cold air around the residence. In the winter, the air current is largely fueled through the bank of windows covering the southern side of the house, while in the summer it gets its zest from the series of windows positioned on the roof.
The buffer zone also promotes ventilation and serves double duty as the secondary living space. Because the temperature of the dynamic envelope isn't as stable as that in the primary space, this portion of an Enertia home is typically geared towards purposes like laundry rooms, recreation rooms, offices or workout rooms.
The Sun Space: The southern wall of an Enertia home is a striking sight. Windows dominate the view, soaking up lots of solar power. In the winter, the sun space acts like the engine of the house, powering the circling convection current to fill the wood with thermal energy. This energy radiates into the primary space, warming the home. Grills in the floor of the sun space allow air to flow up from the basement and continue up into the attic.
Now that we know the main parts of the system, let's see how they all come together on the next page.
The Enertia Building System in Action
To get a closer look at how the Enertia Building System functions, we need to split it up into four distinct scenarios.
Daytime in the winter: In the winter, when the sun travels low across the sky, thermal heat from the sun enters the house mainly through the large array of windows along the southern wall and warms the air in the sun space and the main living area. As the air heats up, it rises and flows around through the attic, warming the wood as it passes. Having transferred warmth to the wood the air cools and sinks, coming down the envelope along the north wall. In the basement, the temperature of the air stabilizes to match the steady temperature of the Earth's crust and is ready to complete another convection loop around the dynamic envelope.
Nighttime in the winter: The pattern of air movement reverses during winter evenings. As the sun sets, the air in the sun space cools a touch faster than the air in other parts of the envelope and it sinks down into the basement before rising up again as it's warmed by the radiant heat stored in the wood. According to Sykes, timber such as southern yellow pine takes about 8 to 12 hours to fully release the heat it has stored, warming the house overnight.
Daytime in the summer: As the seasons swing towards summer, the owner of an Enertia house needs to perform two tasks to prepare for the hot days ahead: open the windows both in the attic and on the northern side of the basement. By doing so, he or she switches out the closed-loop circuit for an open one and enable the house to perform in summer mode. Because the sun's path is higher in the sky during the summer, much of the sunlight is reflected away while the rest goes through a convection cycle which is mainly powered by the windows in the roof. These windows (which open only onto the dynamic envelope and not through to the main living space below) rush heated air out through the rooftop ventilation. This creates a vacuum that draws more air in through the basement windows where it's cooled by the Earth's lower temperatures. Then the cooled air is drawn up by the convection current and proceeds to leech off some of the heat as it makes its way around and out the attic windows.
Nighttime in the summer: Because there's no sun to pull cool air up into the house during summer nights, ceiling fans can be employed to keep the circulation going and ensure things won't be a little too toasty in the a.m. This is one example of keeping the house inside an individual's comfort range. On the next page, we'll examine this concept a little more closely while we take a look at the capabilities of the Enertia Building System to see how it performs in different climates and conditions.
The Capabilities of an Enertia Homes
Although dwellings built with the Enertia Building System naturally take care of a lot of the heating and cooling necessities of a habitat, there are several other factors involved in determining if they'll make a home completely comfortable to live in without a couple of air-adjusting accessories.
Probably the biggest of these is the human factor. There's a good chance you know someone who can't stand to be too hot or too cold. You can most likely also bring to mind people who're fine with a bit of roughing it -- like by letting the temperature slide into the upper 70s before they turn on the air or slip down into the low 60s before the heat comes on. Depending on the type of people living in the home, they might choose to wing it or they might decide to install a heater, air conditioner, stoves or ceiling fans to help out on days when the weather is a bit extreme. Comfortably harnessing one of these homes may take a little time to get used to according to the folks at Enertia, but once you've got the system down it becomes second nature to make the house work optimally.
Another important factor related to this involves radiant heat. According to EBS's president, Michael Sykes, because the primary living space is heated through radiation as opposed to convection, people feel warmer at lower temperatures -- mainly due to the fact that they're protected from drafty changes in temperature and the mild wind chill caused by forcibly moving warm air.
This brings us to a third consideration. In mild climates, Enertia homes are said to be able to function with greater efficiency than ones in more severe climes. For example, out West there's tons of sunshine and not a lot of humidity, making it one of the ideal environments for this sort of home. But if you're looking to build an Enertia house in a less copasetic location, like one that sees days on end of cloudy or muggy weather, you might want to pick up a few pieces of equipment to kick-start and assist the house's natural abilities to heat up, cool off and dehumidify. Also, in some parts of the country you may be required to install at least a minimal heating and cooling system because of local building codes or mortgage requirements.
One plus to consider if you're looking to add an air conditioner is that you won't be shooting this energy right out the roof ventilator. Because the inner shell is a contained area, all that nice cool air will stay right where you want it. Keep in mind too, depending on the size of the appliances used to supply additional heating and cooling -- and the climate of the location -- these supplementary devices may be able to operate through solar panels so they're not creating an electricity load.
EBS homes are purchased as kits, either in basic universal models or in customizable packages. Different add-on features are available and each model can be adjusted to accommodate a variety of climates and site locations. The homes are also built to be easily upgradable if an owner decides to go completely off the grid.
On the next page, you can find lots of links to articles about other inventions that might serve you in your daily life, and some more interesting info about the homes we live in.
Related HowStuffWorks Articles
- 9 Things Invented or Discovered by Accident
- How House Construction Works
- How Patents Work
- 10 NASA Inventions You Might Use Every Day
- Top 10 Wacky Inventions for the Homes
- Why do doors squeak?
- Why do the entry doors to most homes open inward, while in most public buildings, the entry doors open outward?
- Home Design Quiz
More Great Links
- Hathaway, Alden. "Building an Affordable Solar Home." 2/20/2004. (11/24/2008) http://www.ert.net/solarhome/book/Chapter%203.pdf
- Kosny, Jan et al. "Thermal Mass - Energy Savings Potential in Residential Buildings." Oak Ridge National Labs. 8/11/2001. (11/26/2008) http://www.ornl.gov/sci/roofs+walls/research/detailed_papers/thermal/index.html
- Lamb, Robert. "How Weather Works." HowStuffWorks.com. (11/24/2008) http://science.howstuffworks.com/weather.htm
- McIntire-Strasburg. "The Enertia Home: A Modern Marvel, or a Lot of Hot Air?" 7/10/2007. (11/24/2008) http://sustainablog.blogspot.com/2007_07_01_archive.html
- "Modern Marvels Invent Now Challenge Presents the Breakthrough Inventions of 2007" Invent Now. 2007. (11/24/2008) http://www.invent.org/challenge/
- Pogue, David. "A Home That Cools and Heats Itself." 5/17/2007. The New York Times: Pogue's Posts. (11/24/2008) http://pogue.blogs.nytimes.com/2007/05/17/a-home-that-heats-and-cools-itself/?pagemode=print
- Press Kit and Personal Correspondence with Michael Sykes. Enertia Building System. (11/24/2008)
- Sykes, Marvin. "Heat Storage Means." Free Patents Online. 11/11/1986. (11/24/2008) http://www.freepatentsonline.com/4621614.pdf
- Sykes, Marvin. "Method of Increasing Latent Heat Storage of Wood Products. Free Patents Online. 8/23/2005. (11/24/2008) http://www.freepatentsonline.com/6933016.pdf
- Tarbuck, Edward and Lutgens, Frederick. "Earth Science Eleventh Edition." Pearson Prentice Hall. 2006. (11/25/2008)
- The Enertia House Web site. (11/24/2008) http://enertia.com/