Redundancy: Heat Without Fire
About 40% of your home power consumption is for heat. My home uses propane for the furnaces. During design and construction, you can choose from a myriad of options in how to heat your home but you should consider a Passive Solar and Net Zero Energy design to help heat your home. If your home is already built then you are looking at potentially expensive retrofits to change over.
If you care to go over to TheGreatCourses.com, they have a great course called Everyday Engineering and it covers Passive Solar and Net Zero in Lecture 19. Let’s go over each briefly.
Passive Solar basically calls for designing your home to take advantage of free energy available from the sun. It does not use any electrical or mechanical devises to capture the solar energy. It merely incorporates the building’s location, orientation, and design to maximize thermal gain in the winter and minimize it in the summer.
To benefit from direct thermal gain in the northern hemisphere, the long axis of the house is oriented east-west and the side of the building that faces south has numerous large windows that allow sunlight in. As the sunlight strikes the floor, walls, and furniture, it is radiated back into the room(s) in the form of heat. Other sides of the house / building only have enough windows / apertures to allow natural light in. You can also use windows designed to maximize heat gain and minimize heat loss.
A lot of housing developments use standard designs that are oriented towards the street and not necessarily to capture maximum sunlight, especially on cul-de-sacs.
You can also design the window apertures and the eaves to specifically permit maximum light to shine through the window in the winter but shade the window in the summer. Broad leaf trees on the southern side of the house can also provide shade in the summer but in the winter, since the leaves have fallen, sunlight gets through and can heat up the home.
Finally, in areas that are frequently exposed to sunlight, use of materials that serve as heat sinks in the day (such as stone slabs) can then radiate heat back into the home once the sun has gone down.
Net Zero homes strive to produce as much energy as they use – either with wind generators or solar panels. But they aren’t always self-sufficient, they still need power at certain times but overall they seek to provide enough energy to the grid during peak production to make up for usage during lulls. So while this is a good plan to reduce your requirement for energy from the grid or from natural gas / propane, you still need to plan for that EOTWAWKI contingency.
I saw a neat solar heat device on the web that you can build yourself. There are two basic designs:
1. Backpass (baffles, downspouts or cans). For the backpass design you are just channeling the air behind a dark colored absorber. The device(s) looks like a flat panel with a transparent side exposed to the sun permitting sunlight to heat the absorber. The sides and back would be insulated to minimize heat loss. A cool / room temperature inlet at the bottom and a warm outlet at the top permits the device to work without a fan (the warm air rises and sucks in cool air at the bottom). With a small fan you can force more air through the device and harvest more heat. Baffling the air behind the absorber forces more air to be in contact with the absorber longer and you can get a better heat exchange.
Go over to http://rimstar.org/renewnrg/solar_air_heater_types_diy_homemade.htm to see some DIY designs.
2. The Matrix design is similar but the air passes through a screen, coming in contact with the screen and absorbing heat as it passes through.
One DIY’er built a device out of empty soda and beer cans which he stacked up and painted flat black and then mounted on a fiber board backing and covered with plexiglass. The interesting factoid was that he punched uneven holes in the top and bottom of the cans so he would get turbulent (not laminar) air flow, again putting more air in contact with the soda/beer can absorbers and enhancing transfer of heat to the air. Important safety tip: consume all beer at least the day prior to construction for better results.
Well since I started this blog with the title “Heat Without Fire," I think for those days when the sun can’t shine through or during long winter nights, every prepper should also consider augmenting their heat plan with a fireplace, pot belly or Franklin stove or other wood burning device. I grew up in Minnesota and we had a back room that was opposite the placement of the furnace – it was always freezing in the winter. Then we installed a pot belly stove and it was Hawaiian shirts, flip flops and tank tops in that room from that point on. The pot belly was a thin sheet metal design and we replaced it later with a Franklin. The heavy and thick metal sides of the Franklin continued to radiate heat even after the coals died out while the pot belly would go cold quickly. Regardless, they both made that backroom toasty with a small amount of wood.
Fireplaces can be very useful too, especially if you have a lot of stone around the mantle which can serve as a heat sink and radiate heat. But personally, I think walls units (while they look great) draft too much cold air into the room and exhaust too much warm air out the chimney. To enhance the heat gain, you can install a convection air insert in the fireplace to move air around and behind the firebox and push it into the room. To each his own…
Try to capture as much heat in the exhaust pipe as you can, using an exposed multi pipe manifold if practical, so it has a chance to radiate heat into the room as the warm air goes out the top.
While many of our modern homes have an open design, this might not be the best in a grid-down situation. Be prepared to isolate or block off certain rooms that you don’t need to use. Smaller spaces heat faster than larger spaces. Since heat rises, rooms with high ceilings tend to be harder to keep warm (at least near the floor where you are).
If it comes down to it, don’t forget where the band “Three Dog Night” got their name – Eskimos would bring more dogs in the igloo to get more body heat on really cold nights, so this is another reason to have a big dog in the home.
If you don’t have a dog, well then you might have to spoon with your buddy to share body heat. If you don’t know what spooning is, well at least it is not scissoring. But it brings a whole new meaning to make your buddy smile. My German Shepherd providing heat in the home….
Primary – you have designed your home / safe haven to use passive solar and/or Net Zero design features. Regardless, you have a primary means of heating your home.
Alternate – augmenting your heat plan with solar heating using convection or forced air to circulate cooler air out and warmer air back into the heated space.
Contingency – wood stove or fireplace to heat the home when the power is out or the solar heater cannot operate.
Emergency – three dog night and spooning!
Keep on prepping!
De Oppresso Liber