On Thursday, February 08, 2007 6:07 AM Steven Holt wrote: My comments in line:
>Geothermal mixed with a heat pump which I think is what you are talking about is a highly viable >technology in most areas of the country for both heating and cooling, working off the relatively >shallow depths where the earth stays an average of 55 degrees. Straight air to air heat pumps >can become far less efficient at very low outside air temperatures. This is a vastly different >system from what you may have heard about in school - drilling for magma heated steam. Which is >presently practical mostly at an industrial scale in areas where geologically speaking there was >near surface magma or relatively recent surface lava. With this said, 9 out of 10 houses in >Iceland are heated by geothermal systems. NPR just ran a story about a laser drill bit for >digging down miles for the ubiquitous deep geothermal heat, but this is presently just a pipe >dream. Ouch! I heard of a gentleman on the Eastern Shore of Maryland that spent $20K for geothermal for his 6,000 sqft house. Seems like he would have to live there for many years before getting a payback on that investment. >For retrofits, your best initial investment is almost invariably in insulation and surprisingly >storm windows are usually better insulation than even the highest r value, low e argon filled >double pane glass windows coming in at about r-6. It may be a real pain, but you can always add >low e argon after the more inexpensive storms. I agree that windows do make a difference. >Solar domestic water heating is a mature technology that often has the fastest payback, also >look for any tax incentives in your state or potentially coming at the federal level. In my situation, I have a well/pump that costs about $35-50 a month to run so that we have water. I looked into running that by solar and it was not cost efficient. Plus, Virginia gives me no tax breaks. >My personal preference for new construction is passive solar with super insulation in the form >of plastered straw bales for wall construction. If you are not in the southwest where it is >becoming more commonplace, you may get the unmitigated joy of educating the county's building >department and inspectors. I had not heard of straw bales for insulation. Our builder has one of the form machines to spray into the walls. >As to the bad solar experience it sounds like you had a design with insufficient: provision for >summer shading, thermal mass and insulation. Not all areas will have enough sun when needed but >in the sunny southwest it is very possible to do most if not all heating and a hell of a lot of >your cooling via thermal mass with nocturnal cooling. Walls made of stacked tires filled with >dirt - the earth ship method - are great for down there (but lots and lots of backbreaking >work). >For electricity, personal wind power is great for limited good wind sites, particularly if you >have the room for a tower to fall. Solar is presently expensive per kwh but will probably be >coming down fast as thin film newspaper style printing technology comes on line. Google based >investors have a large plant in the works. If you can grid tie to the power company with >either locally, you won't need banks of expensive relatively short lived batteries, your >electric meter spins backwards and that must simply be a fantastic feeling. Unfortunately, grid >tie inverters are not particularly cheap. Thanks for the information! David L. Crooks _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
