Posted on 09/25/2014 11:16:29 AM PDT by Prophet2520
That was just my off hand opinion back when the cost of natural gas was real low in the midwest with electricity low as well. In current utilities, the payback was probably pretty prompt.
“system is yet unplanned, so....i like the idea of the use for air conditioning as well....i am already at least contemplating many of these concepts. house will be in north-eastern Maine”
Hi neighbor. I am in NH. Spend a little more to super insulate. Just be aware that a tight house can reduce air quality. Either keep a good supply of indoor plants (or aquaponics) or get some sort of heat exchange air handling. There are passive and cheap versions of this, and expensive active versions.
For south facing windows the ideal is high Solar Heat Gain Coefficient (SHGC) windows. Look for over 0.3. The higher the better. Window selection is personal and budget based too. I like reusing second hand patio sliders. You still get pretty good performance at dirt cheap prices. A good high SHGC window is more effective but window costs can add up.
With some roof overhang in Maine you should never need air conditioning. An attic fan run at night will cool everything down, and if you have built in thermal mass and/or earth sheltering that will help all day.
I would do several of the suggestions by Freepers on this list before I installed a Geothermal system. The return on investment is just too long. As stated by several others, many of the passive solar designs can easily be incorporated into new construction without any added major costs.
The most important thing is insulation. Energy costs will continue to rise. Therefore, limiting the energy it takes to heat and cool your house will always be your best ROI.
I built a center chimney cape in 1989 in southern NH. I used the best low E glass window that Anderson made. I framed it with 2x6 walls, Tvyec wrap, and R 40(12” bonded cellulose) in the ceiling. I had a small Jotul woodstove in the center of the house up against the stairway to the second floor. I did not have big overhangs because capes do not have those. However, in the summer I would open the windows at night , close the shades on the south side of the house during the day and when I came home after work the house was still 72 degrees. In the winter I could heat the house with that small woodstove.
Since then I have owned two houses that were built in the early 70s. On both of them, I insulated, changed exterior doors, caulked, etc. They will never be as good as the house I built in ‘89. I just installed a Harman pellet insert. Heating oil here is now $3.49/gal. It costs about $3500 now to heat my house in the winter. I figure it will take about 3 years to pay off the pellet stove. I am in the process of replacing all the exterior doors. Replacing the windows is too expensive.
well, the windward side will be totally underground, and the two sides partially underground. one of those is the garage, so...south facing windows is the plan, as is a big overhang.
there will be a hollow air space along the windward side, and the garage counts as an air space albeit a big one.
a central fireplace is also in the plans, as is one in the master bedroom.
looked at active solar (money pit), wind (worse). i could live with the ten year payback for geothermal provided that it actually works. i’ve been told that the operating costs compare to a refrigerator...
The other thing I would install if I was building a new house is metal roofing. It eliminates ice damming issues. It will last for 50 years or more. It is not nearly as big of an upcharge over asphalt now as it was a few years ago.
There may also be a tax credit on the lighter colored varieties.
Like NH, you will probably never have a natural gas pipeline in front of your house, unless you big in a city.
Therefore, your energy choices to heat with are: oil, propane, cord wood, coal and wood pellets. All of those choices have drawbacks. None are getting cheaper, except maybe coal.
i am trying to take heed of many of the suggestions that i get from here and other sources. what might be nice would be to have the university of Maine or some such entity help with the costs in return for study...(hehhehheh)
will probably break ground, funding contingent, in about a year
Instead of a central fireplace, you may want to consider a soapstone woodstove. Check out the Progressive Hybrid made by Woodstock Soapstone out of Lebanon, NH. This was the stove I was going to install, prior to my wife convincing me to good with the Harman Pellet insert(we are in our 50’s and have burned wood for 20 years). You get the thermal mass with much higher efficiency(81%). IMO, this is the best woodstove in the market today.
http://www.woodstove.com/progress-hybrid
steel roofing? certainly on the above ground portion....
If you put that stove centrally located on a masonry hearth I would think you could easily heat a well insulated house with it. I would design it so the reverse side of the hearth is a heat sink(facing south) like described by myself and others earlier.
You can always just brick them over, like I did.
Who needs windows anyways?
interesting article. i bookmarked it...
any thoughts on them gizmos that go on the flue pipe that one blows air through to get more heat from the flue? i forget what they’re called, but they mostly are just tubes, and some have small fans on one side...
I cant quite tell from your description the orientation of the garage. If any wall on it is facing south I would recommend windows there as well.
Wind - check out this site. I do not own one of these, but if I were building right now I would seriously consider combining this with PV. Often when the sun is not there the wind is. They are a great complement. http://www.mikeswindmillshop.com/product-category/wind-generators
For solar electric look here:http://sunelec.com/
Solar panels are SO cheap now. Less than one tenth the cost of fifteen years ago. If you are willing to do-it-yourself a bit, the payback is very quick. For example see these at 34 cents per watt. http://sunelec.com/solar-panels/tianwei-90w.html
The geothermal heat pump costs vary considerably on the site. New England is rocky and ledge is common. These can make costs very high.
I hope when you say central fireplace you actually mean central woodstove. Fireplaces do offer thermal mass advantage but that is offset by terrible efficiency. A masonry stove is a beautiful option. It is VERY efficient, Very clean burning, and great thermal mass, but they must be custom designed and built for the site and so are expensive. see https://mainewoodheat.com/masonry-heaters/
Depending upon your thermal mass, insulation, and amount of south facing glass per sq ft., a single wood stove run on cold winter nights is normally plenty for every 2500 sq ft of house. This also depends upon layout and ability of heat flow. I designed mine especially so that the heat flow from one wood stove would heat the whole house in a pretty balanced distribution.
thanx for the info. btw: garage would be on west side
There are different versions of this(stove fans). Some like you describe, some just sit on the stove, or you can place a regular fan in the room to blow across the stove.
The biggest difference is in your stove selection. If the woodstove is in your main living area, a fan can help you control heat distribution to create more comfort, not necessarily more efficiency. Flue pipe ones can actually increase creosote and decrease efficiency by reducing flue temp. It is a toss up.
The layout of where the stove is and natural airflow makes a big difference. Personally I have not used one of those fans. If I were to put the stove in the main living area I would probably place a normal fan in the room to control airflow. I really like ceiling fans and high ceilings in passive solar homes. Normally people recommend against high ceilings because when you have to burn fossil fuel to heat that extra space it is costly. When you are getting free solar energy though there are many benefits. Also ceiling fans are much more energy efficient than your typical fan.
Lots of other good answers; but I feel compelled to throw my depreciated $0.02 in.
The real point of passive is to take a realistic look at what the outer limits are, and design the house accordingly. Most homes are _not_ designed this way, and throw in a costly HVAC system to compensate for not spending the same cost (or much less) on doing it right from the beginning.
First off, realize that sufficient insulation will mitigate most HVAC needs outright. Thicker walls with better insulation will stabilize indoor temps; an earth-berm home with feet of dirt on 5 sides and a sensible front will stay around 50 degrees. A more normal home design can still reduce temperature standard deviations and change rate by just putting in better/thicker insulation during build.
Once you’ve got the standard deviations and “extreme temps for weeks in a row” covered to your satisfaction (say, 1 degree per day internal temp change for 2 standard deviations extreme outdoor temps), then of course you’ll have to include active HVAC. But since you’ve already covered nearly all conditions with passive systems, the active systems have to address a far smaller range & load: one carefully-chosen decorative wood stove/fireplace solves the “outside temps below zero”, and one modest AC unit solves the “outside temps in the high ‘90s” - with each only having to supply HVAC for a much smaller range of rare conditions outside the range of passive systems.
The technology is very well understood for decades (centuries? millennia?). Short answer is: run the numbers on insulation, wall exposure (size & orientation vs solar impact), air circulation, thermal mass, and expected temperature fluctuations. A double-walled exterior with good circulation, thick insulation, and latitude-appropriate southern wall arrangement will go a LONG way to cutting HVAC costs close to nil.
“Conservative” does not equate to “anti-environment”.
Random example: George W Bush’s ranch home in Texas is largely a “passive” design, requiring very little HVAC costs (for 4000 sq ft!) despite fairly extreme conditions.
camle, the calculations can get complicated. Be careful about assumptions on earth-sheltering effects. Remember in Maine, in the winter, the ground can freeze to almost three feet deep. Meaning the top foot of soil is VERY cold. A LOT of heat is lost in a concrete against dirt scenario. I strongly recommend some external rigid insulation to maximize the earth sheltered home in Northern climates. There are different ways to apply it, horizontal, vertical or both, but all are very helpful.
Be aware also of the thermal flywheel effect of windows. If your toleration for temperature swings is low, use less glass and more insulation. Insulated shutters are very helpful for cold winter nights, but unless automated can be tiresome to some people.
Ya. That is what I thought. But it is free energy. Maybe a heat pump?
Non passive = photovoltaic cells to generate electricity.
Passive (everything else) = uses the heat energy and the heat transfer process to do “passive” things like heat water, heat the house in winter, etc. It can be as expensive as a solar cell heat exchange system or a barrel of water painted black.
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