I have been doing a lot of research on green homes, i.e. net zero homes in an attempt to make it a practical conversion from a typical suburban home in a northern climate. I'm not an expert at green homes at all, but I want to put down some thoughts, maybe others will correlate or correct.
The typical net zero home usually involves making the outer surface area of the home as minimal as possible (i.e. a box). then adding tons of high-quality insulation, careful for cracks, triple-pain windows. Having most windows pointing toward the equator, some east and west, and very little towards the poles, basically only
enough to let natural light in. Then, efficient appliances,
hot water heating, and lighting. Then, since everything is so sealed, they have an air exchanger so no one suffocates unless the electricity goes out, then, since electricity is needed, they load the top of the house with
solar panels and install a battery cabinet.
The typical wofati is a cave with glass windows facing toward the equator. Some have earth-battery tunnels (a fan and tunnels into the earth).
The typical northern house, especially older and suburban is a box. Sometimes there's an additional room. Ours has one. Until it can be insulated to mimic a wofati, it is curtained off with the understanding that is a great storage area.
Windows facing the equator is different in each house. Ours was chosen for lots of natural light (for plants and humans in winter). Most are facing the equator, however, there are plenty facing the pole. This can be fixed by exchanging, plastic/rubber overlays, shutters, window quilts, heavy curtains in some sort of combo (taking into consideration the need for natural light). For instance, we have a balcony door facing the pole that's all window and another door in the house that's facing the equator that's mostly solid. A quick switcheroo would correct that.
With
solar energy, you need a surface for absorption, which means dark colors and thermal masses. By painting the swath the window light travels across during winter a darker color, especially having the material being a thermal mass, you can absorb the energy from winter better. Paint is not too expensive, 20-30 a can. Cement board ($10), cement coloring ($
, and a bag of fine cement ($15) = a thermal mass. You can also use
cob, which some people can locate for free. And, pick up some black furniture or furniture covers ($20) or black rug.
Insulation in a suburban home is usually nothing special. Probably a going over with an energy audit to find holes and get the insulation up to 30R across the board would be a good idea. Most old insulation jobs are not up to code, and with the pressure differential between inside and outside any insulation gap jets cold air in and hot air out. Most net zero homes have an R of 60 or more, but I read there's a certain drop-off in value at a certain point on the insulation front, so 60R + might be over-kill.
Another thing to consider is thermal bridging. If insulation is installed inside the home, like they are experimenting with in the U.K., then this might be helped, but even still I'm not sure it's a huge difference, so in my house I'm going to do about everything else first.
Window thickness in most homes is double-pain, some with additional storm windows. However, the more panes, the less light (the more refracting), so I'm not sure this is worth it on the equator facing. On the pole facing, this might be good, but a much more expensive than the ones mentioned above.
Most older houses in northern climates have a basement. This is for storage, safety, and as a temperature regulator. For this reason I prefer a deeper, less finished basement. For those that aren't deep or are really finished, perhaps some wall venting or burying the house up to whatever it can take structurally is a good option. I found that our house was, for whatever reason, about 2 ft higher out of the ground than necessary, which was also causing the slope and rain to go towards the basement. Dirt was all that was necessary to correct that. Where the structure is not as strong, perhaps a retaining wall can help.
Lighting and appliance efficiency. We are slowly eeking towards
LED and lizard-lamps (that contain mercury and thereby help with vitamin D deficiency). Most people do that because most people can't seem to remember to turn off the
lights when they leave the room. I considered sensors to regulate this, and maybe will in the future, but there are some more important (in my opinion) efficiency issues.
1: managing your heat vents. Don't heat rooms your not in. Don't close all your vents but, why heat the guest room or mud room?
2. adjust your heat intakes. Some furnace intakes are in odd places that don't make sense. One of ours is right under a window that if we close the curtain,it sucks the cold air we are trying to hide behind the curtain into the house. We will be moving that vent about 1 foot into the room by building it into a simple bench.
3. Separate out lights and fans you don't need. Sometimes a whole bunch of light is on one switch, when you only need one. In our case our bathroom fans are attached to the bathroom light. So, if it's a cold night and you want to see your teeth as you brush them you are forced to turn on a fan that sucks the hot air out of the house.
4. Heater choice. If
wood is abundant, use this for general heating. It has a 270%+ efficiency (heats on chopping, hauling, & burning). However, most suburban homes are large. Instead of fully heating the house, heat your house to barely passable and then heat yourself or the space you are in. Space heaters do rooms. Heated blankets and pads do people/things. Use a bit of elastic and a few nails to keep room doors closed so the space heater doesn't attempt to heat the whole house. Have warm blankets, robes, pjs, slippers, socks, etc. So people are comfortable with less heat. Place a heat lamp above the dining room table, cook instead of ordering in or microwaving a meal. A soup pot or stew humidifies and heats. Get a fuzzy pet and train them to sit on your cold feet or lap. Share your house, have guests. Have hot tea or
coffee.
Also, use windbreaks by placement in your
yard of things like garages, sheds, wood stacks, thickets.
After that, then there's solar, wind, and human power to help with the remaining energy needs.
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For summer, here's my thoughts:
The thermal mass, basement, and insulation will still benefit you. The trick is shading out the sun using pergolas or arbors and
trees on the equator side. The sun coming in here during summer has been calculated to approximate me using the
wood stove all day full blast. Simply blocking that out will result in a strong reduction in air conditioning needs.
Most old houses here are set up so that they can catch a nice breeze. Use this by opening the basement windows and attic windows, top-down.
Also, go outside a lot. Humans do have SOME ability to adapt to their climate, so going outside will help your body compensate and then not feel so hot or cold. (accept perhaps when I'm fighting a bug, but I think that happens less when you get down and dirty with your
local soil microbes).
Use fans as necessary. Fans can even be solar powered. Roof vents are possible...but I found that the houses here really don't make them necessary. Cold drinks and frozen stuff also help. Kiddy pool. Out-door kitchen.
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In summary, though the net-zero homes are pretty cool, I think that homes that exist now can certainly get a lot closer to net zero than they are with very little money to get there, and any money put in
should pay for it's self in barely any time. I don't think zero will be achieved, but zero now usually is only with the help of lots of solar panels which we are not compensating for their manufacturing costs.