Question:
- Hide quoted text — Show quoted text – >The latest issue of Hubbard’s Pool and Spa Marketing describes a number of >interesting safety covers which look like they could become R10 pool covers, >with a little imagination… >One interesting one is the deck-anchored "Hover Cover" from Hollenbeck >Industries. which "creates the chararcteristic ‘domed’ design by using >air-supported reinforced vinyl material over the pool surface. Air pressure >is created by a shop vac or air compressor that is attached to a fill port >on top of the cover. The above ground version of the Hover Cover is secured >to the side of the pool with a cable that is threaded through grommets in >the cover material and tightened with a winch. Special hooks are also >attached to each upright to ensure that no gaps are left around the cover’s >perimeter… [with] a skirt of material that hangs down inside the pool wall >into the water, creating an air seal around the cover after it has been >anchored." >There’s a description of the 12/91 ASTM standard for safety covers, which >specifies that any gaps around the pool be small enough that a test object >be unable to pass through, and that covers for pools >8′ diameter or width >support a minimum static load of 485 pounds, the combined weight of 2 >adults and 1 child in a standard rescue operation. >There’s a picture of a Hover Cover in the magazine. It looks to be about 3′ >tall in the middle, and tight as a drum, with crinkled sides, and opaque. >Seems like this could be a nice R10 solar pool cover if it had a solid >insulating deck for safety purposes, that sank for swimming, and a tall >transparent vs squat opaque top, with a reflective north wall, and some >sort of airlock door, and a lower pressure, eg 1/4" H20 (over a thousand >pounds for a 24×36′ pool), like a commercial plastic film greenhouse. >Nick
Nick, The cover you are refering to in the article is a winter cover. It is designed to be used while the pool is closed for the winter season. It is not intended that this cover be used during the swimming season, as it is entirely impractical to remove it swim and re-install it every day. This idea of a solid sinking deck is really scary, as well as being ridiculous. First it would not conform to ASTM standard you quote, secondly it would present a real peril and safety hazard, and third would be ridicously expensive to install and maintain. Please, before you take a little information and draw straight line conclusions, get a broader based knowledge of the industry you love to belittle. (maybe read another magazine?) Andy McKegney C.E.T.
Response:
>The Comfort Spa (109 Woodbine Downs, Unit 3 & 4/Etobicoke, Ontario M9W 6X1, >(416) 213-9929) is octagonal and weighs "70 to 100 pounds." Their ad has a >picture of 2 thin people lifting one up on top of a car. The Comfy 1 model >fits 3 people, the Comfort Spa fits 6, and the Turbo Spa features "all of >the latest design innovations." >The ad says it has a marine grade vinyl exterior, and an interior liner of >poly tri-ply PVC reinforced with a nylon scrim, and a schedule 40 PVC frame, >and polyethylene foam insulation, and a limited 5 year warranty.
Nick you have completely missed the point of this product…. It’s portable, it’s not meant to be kept in one place!! (it’s a toy!) >On a typical day, we might supply 6624/24 = 276 Btu/hr to the spa by pumping >276/20 = 13.8 pounds per hour or 0.029 gpm from a drum up into the spa, with >a 12 V 4 gpm pump running less than 1% of the time, while letting some spa >water flow back into the drum. On a sunny day, we might pump some pondwater >into the spa, and let it overflow on the ground, using no chemicals.
Ignorance rears its’ wooden head again! mmmmm hot pond water – let’s sit here it it and watch the scum grow!!! Did you also notice in the advertisement the bubbling water around the two "happy owners"? It is very easy to heat something that doesn’t lose heat – like a covered well insulated – UNUSED spa. As soon a spa owners get in and use it for 15 minutes with the jets blowing, the heat loss goes through the roof (and everywhere else:<) . All off your calculations are for naught. Please learn something more about the industry before espousing such nonsense. Andy McKegney C.E.T.
Response:
- Hide quoted text — Show quoted text – >The latest issue of Hubbard’s Pool and Spa Marketing describes a number of >interesting safety covers which look like they could become R10 pool covers, >with a little imagination. >Here’s a quote from the editorial page: > The National Spa and Pool Institute out of Alexandria, VA provides > quarterly trend reports which offer insight into consumer buying trends > through surveys. Their first quarter report for 1996 indicated that the > desire by consumers in the United States to own an inground swimming pool > had fallen by 33.3 per cent from nine per cent of consumers surveyed in > October 1995, who were "very interested" in owning an inground pool, to > only six per cent who had a strong interest in the April 1996 survey. The > number of consumers interested in an above-ground pool or spa remained > unchanged at levels of three per cent and eleven per cent respectively. > At the same time, Thom Blischok, a business consultant who recently spoke > at the CEO Leadership converence in Washington, sponsored by NSPI, has done > new research on consumer attitudes as well as industry attitudes and he > feels that the "disconnect" between what consumers want and what the pool > and spa industry is currently producing, marketing and selling creates a > major gap in the selling process. > According to Mr. Blischok, it appears that consumers see the industry as > price-driven, fragmented, offering no innovation and that the products > are of questionable quality. >Nick
Hey Nick, I’m glad to see you made the effort to read the article I refered you to a few postings back. Good for you. While the article you quote is true regarding the numbers of people interested in owning an inground pool dropped between October 1995 and April 1996, this should hardily be a surprise! We had a record hot summer (1995) followed by a very miserable Spring (1996) I’m surprised the numbers weren’t worse! Regarding Mr. Blischok’s observations, Again I believe this is true, and the fact that the pool industry ignores solar pool heating is a symptom of this malaise. (not the other way around) Again I point out THE SOLAR POOL HEATING INDUSTRY IS NOT THE POOL INDUSTRY!! This fact seems to continually elude you. I pointed out this issue of the magazine because of its’ article on solar blankets & rollers. None of these systems have the potential to be R-10 covers – unless (and this might happen someday) someone can come up with a flexible, waterproof, UV resistant, physically tough & light-weight material that has a (conductive) R value of 10 in a thickness less than half an inch. Oh, BTW,,,,,, it must also be cheap.(less than 50 cents/ft^2). If this magical material existed, there would be thousands of applications – not just for pool covers! Until then I’ll still encourage pool owners to use a solar blanket and heat their pools with a solar system (if they want to heat it at all). PS. The vast majority of my systems go onto pools already built. If I have the chance to talk to a pool purchaser, I do recommend energy conservation be considered during the construction stage – proper water drainage & insulation if they’ll consider it. However most pool companies just want to build a pool the way they have for the last 25 – 50 years. Andy McKegney C.E.T.
Response:
The Comfort Spa (109 Woodbine Downs, Unit 3 & 4/Etobicoke, Ontario M9W 6X1, (416) 213-9929) is octagonal and weighs "70 to 100 pounds." Their ad has a picture of 2 thin people lifting one up on top of a car. The Comfy 1 model fits 3 people, the Comfort Spa fits 6, and the Turbo Spa features "all of the latest design innovations." The ad says it has a marine grade vinyl exterior, and an interior liner of poly tri-ply PVC reinforced with a nylon scrim, and a schedule 40 PVC frame, and polyethylene foam insulation, and a limited 5 year warranty. What would it take to solar heat this thing, assuming it’s about 5′ diameter, with R20 sides and cover? Say, sit it on top of 4 plastic 55 gallon drums inside some R10 insulation (2" of Styrofoam, with latex paint on the outside), and add a 4′ tall x 16′ long polyethylene film window w on the front: 2′ —– / D /| D D | 5′ /r g D g r / w w w w w w w w w 16′ reflecting pool The inside wall marked r might be reflective, with polycarbonate glazing g over the 5 south sides of the drum enclosure. This could be a direct gain system, with sun shining in on the drums. If there were a reflecting pool in the front, the drums might receive 1300 Btu/ft^2/day x 64 ft^2 x 0.9 x 0.9 = 67K Btu/day of sun where I live, with an average outdoor temperature of 36 F in December. The thermal conductance from the drums to the outside air would be about 20ft^2/R20 = 1 for the top, 24ft^2/R10 = 2.4 for the 3 north sides, and 40ft^2/R2 = 20 for the other 5 sides, for a total of 23.4 Btu/hr-F-ft^2, ignoring the spa for the moment, so we might find the steady-state drumwater temp T from 24hr(T-36)23.4 = 67K, or T = 36 + 67K/5612.6 = 155F. Assuming we could make the water that temperature (unlikely, with radiation losses) what happens after a cloudy week? RC = 4×500/23.4 = 85 hours, so T(168 hours) = 36 + (155-36)exp(-168hours/85 hours) = 52 F. Storing heat for a cloudy week is difficult with a direct gain system. Should we replace the $3 piece of R1 poly film with $2500 worth of R8 windows? ("Of course," window manufacturers might say 
Or make it an indirect gain system, with an air heater on the sunny side, and no airflow at night, with a conductivity of 1 for the top and 64ft^2/R10 = 6.4 for the sides, so RC = 4×500/7.4 = 270 hours? Then, if the water started at 136 F, after a cloudy week it would be about 36 + (136-36)exp(-168/270) = 89.7 F. Better, but still not warm enough. Let’s add more insulation: with R20 sides we have RC = 2000/4.2 = 476 hours and 36 + exp(-168/476) = 106 F. But each 55 gallon drum has a surface area of about 25 ft^2 and a still air surface film conductance of about 40 Btu/hr-F-ft^2, and we have 64 ft^2 of glazing, for a thermal mass area/glazing area ratio of less than 2… So to get 400 Btu/hr x 64 ft^2 = 83 K Btu/hr of full sun with reflection into the drums, we need air around them that is about 83K/(4×40) = 519 F warmer than the water inside. How can that be improved? Increase the surface area by placing 3 8×8x16" concrete blocks with 3 holes in them under each 3′ tall drum, and put 2 1 liter soda bottles full of water in each hole? Each block adds about 6 ft^2 of surface, and bottles add about 1 ft^2 each, for a total of about 4drumsx3blocksx12ft^2 = 144 ft^2 more area. And let’s fill up the 1ft^2 x 4 ft tall hole between the drums with another 13×4 1 and 2 liter bottles, for a total mass surface of 300 ft^2, reducing the required air temp to 184 F warmer than the drum water, in full sun. But only about 80% of the sun will pass through the glazing, reducing the delta T to 148 F. Making the drum surfaces rougher and moving air at 4 mph past the drums should increase their thermal conductivity to 2+4/2 = 4 Btu/hr-F-ft^2 and decrease the delta T to a more reasonable 83K/(300×4) = 69 F. Or, we could just reduce the solar glazing, since we are collecting about 10 times the solar power needed to keep the tub warm. Just glazing the 3 south sides gives 24 ft^2 of solar aperture, about 4 times more than needed: 2′ —– / D | D D | 5′ g D g g g g reflecting pool Now the solar glazing/thermal mass area ratio is about 12:1, and full sun is about 5760 Btu/hr, and delta T = 5760/(300×4) = 5 F. About 28 K Btu/day of sun shines in through the glazing, and about 6 hr(T-36)24 ft^2/R1 of heat is lost through the glazing each day, making the linear water temp prediction approximately 36 + 28K/(6×24) = 231 F. Still warm enough The spa itself might have a thermal conductivity of about 1 for the top and 3 for the sides, losing 24(105-36)4 = 6624 Btu on an average December day. The lower part would have a thermal conductivity of about 64ft^2/R20 = 3. The 55 gallon drums have a thermal mass of 4×55x8 = 1760 Btu/F, and the bottles add about 60 x 4.2 = 252, for a total thermal mass of about 2000 Btu/F, so a cloudy week might look like this: day drum temp drum loss spa temp spa loss total loss 0 136 F 7200 Btu 105 F 6624 Btu 13824 Btu 1 129.1 6703 105 6624 13327 2 122.4 6223 105 6624 12847 3 116.0 5758 105 6624 12382 4 109.8 5314 105 6624 11938 5 103.8 4884 103.8 6509 11393 6 98.1 4471 98.1 5962 10433… On a typical day, we might supply 6624/24 = 276 Btu/hr to the spa by pumping 276/20 = 13.8 pounds per hour or 0.029 gpm from a drum up into the spa, with a 12 V 4 gpm pump running less than 1% of the time, while letting some spa water flow back into the drum. On a sunny day, we might pump some pondwater into the spa, and let it overflow on the ground, using no chemicals. Nick
Response:
The latest issue of Hubbard’s Pool and Spa Marketing describes a number of interesting safety covers which look like they could become R10 pool covers, with a little imagination… One interesting one is the deck-anchored "Hover Cover" from Hollenbeck Industries. which "creates the chararcteristic ‘domed’ design by using air-supported reinforced vinyl material over the pool surface. Air pressure is created by a shop vac or air compressor that is attached to a fill port on top of the cover. The above ground version of the Hover Cover is secured to the side of the pool with a cable that is threaded through grommets in the cover material and tightened with a winch. Special hooks are also attached to each upright to ensure that no gaps are left around the cover’s perimeter… [with] a skirt of material that hangs down inside the pool wall into the water, creating an air seal around the cover after it has been anchored." There’s a description of the 12/91 ASTM standard for safety covers, which specifies that any gaps around the pool be small enough that a test object be unable to pass through, and that covers for pools >8′ diameter or width support a minimum static load of 485 pounds, the combined weight of 2 adults and 1 child in a standard rescue operation. There’s a picture of a Hover Cover in the magazine. It looks to be about 3′ tall in the middle, and tight as a drum, with crinkled sides, and opaque. Seems like this could be a nice R10 solar pool cover if it had a solid insulating deck for safety purposes, that sank for swimming, and a tall transparent vs squat opaque top, with a reflective north wall, and some sort of airlock door, and a lower pressure, eg 1/4" H20 (over a thousand pounds for a 24×36′ pool), like a commercial plastic film greenhouse. Nick
Response:
The latest issue of Hubbard’s Pool and Spa Marketing describes a number of interesting safety covers which look like they could become R10 pool covers, with a little imagination. Here’s a quote from the editorial page: The National Spa and Pool Institute out of Alexandria, VA provides quarterly trend reports which offer insight into consumer buying trends through surveys. Their first quarter report for 1996 indicated that the desire by consumers in the United States to own an inground swimming pool had fallen by 33.3 per cent from nine per cent of consumers surveyed in October 1995, who were "very interested" in owning an inground pool, to only six per cent who had a strong interest in the April 1996 survey. The number of consumers interested in an above-ground pool or spa remained unchanged at levels of three per cent and eleven per cent respectively. At the same time, Thom Blischok, a business consultant who recently spoke at the CEO Leadership converence in Washington, sponsored by NSPI, has done new research on consumer attitudes as well as industry attitudes and he feels that the "disconnect" between what consumers want and what the pool and spa industry is currently producing, marketing and selling creates a major gap in the selling process. According to Mr. Blischok, it appears that consumers see the industry as price-driven, fragmented, offering no innovation and that the products are of questionable quality. Nick
Response:
: : Marc : : Its not the people within my industry that Im : concerned with. Its the casual, leisurely reader : like you that may be swayed by the loudest voice. : Speculation with no practical back up is no more : than speculation. : : People in my industry have already done the lab : work and know what the result is. Thats why we are : not pasting plastic greenhouses around the : neighborhood. : : Youre right I have a bad attitude when I talk to Mr : Pine. But I feel better now. : : Dan Yeh sure, what ever turns you on Pal.
Response:
(BIG SNIP from a number of posters) – Hide quoted text — Show quoted text ->We have gotten > tired of being insulted by someone who was initially orders of magnitude > off in his calculations. Now he is slowly getting closer, and may be > within a 75% margin of error. > We believe it is unethical for someone to denigrate the accomplishments > of all others while not even having a functioning ’solar closet’ to hold > up as proof. > I am an active solar proponent; just visit my web-site. I’ve also made > my own homegrown solar components and encourage everyone to try it. > Just don’t be surprised if you are disappointed with the results of a > Nick Pine design. > Cheers, > — > William R. Stewart
William, I am brand-new to this list, so I really don’t know much about the dynamics of ongoing discussions. But I have a question about whether solar ponds have been discussed as a means to produce electricity? I read some time ago of one in Israel; perhaps someone has read more recent literature on this. Thanks, Dale
Response:
> Daniel, I’d say think again what science is and what makes a scientist. I > think you’re being insulting insinuating that Nick is seriously conspiring > to destroy your industry or that there are people in your industry with out > the mind to evaluate Nicks thoughts on there own. Many people like myself > come to these newsgroups not just for some serious discussion but also for > a chance to talk about ideas at leasure in the casual hope that there may > be some interesting spin offs. I don’t see how your attitude helps anyone, > but then again I say "who the hell am I" ? > — > Marc O’Brien > Industrial Refrigeration Mechanic
Marc Its not the people within my industry that Im concerned with. Its the casual, leisurely reader like you that may be swayed by the loudest voice. Speculation with no practical back up is no more than speculation. People in my industry have already done the lab work and know what the result is. Thats why we are not pasting plastic greenhouses around the neighborhood. Youre right I have a bad attitude when I talk to Mr Pine. But I feel better now. Dan
Response:
> Daniel, I’d say think again what science is and what makes a scientist. I > think you’re being insulting insinuating that Nick is seriously conspiring > to destroy your industry or that there are people in your industry with out > the mind to evaluate Nicks thoughts on there own. Many people like myself > come to these newsgroups not just for some serious discussion but also for > a chance to talk about ideas at leasure in the casual hope that there may > be some interesting spin offs. I don’t see how your attitude helps anyone, > but then again I say "who the hell am I" ? > — > Marc O’Brien > Industrial Refrigeration Mechanic
Perhaps you’ve only seen some of Nick’s posts. In many posts in the past, Nick has pushed his variations of another’s effective solar solutions as the only real way to implement solar energy capture and distribution. He has called those who do not discard all existing solar technology for his ‘criminals’, ’stupid’, ‘crooks’, etc. We have gotten tired of being insulted by someone who was initially orders of magnitude off in his calculations. Now he is slowly getting closer, and may be within a 75% margin of error. We believe it is unethical for someone to denigrate the accomplishments of all others while not even having a functioning ’solar closet’ to hold up as proof. I am an active solar proponent; just visit my web-site. I’ve also made my own homegrown solar components and encourage everyone to try it. Just don’t be surprised if you are disappointed with the results of a Nick Pine design. Cheers, — William R. Stewart http://www.patriot.net/users/wstewart/first.htm Member American Solar Energy Society Member Electrical Vehicle Association of America "The truth will set you free: - J.C.
Response:
> >Nick a free minded creator? Has he created thing one? > Sure. For instance, a house in PA that used only 25 gallons of oil last winter > for heat,
This was not your original idea, but that of Norman Saunders. > a 7×11′ Trombe wall,
Again, not an original idea on your part. You also disparage Trombe walls. > the first > Intelligen cogen installation in Pennsylvania,
A creation of yours? Or simply an installation? > a 2000 ft^2 greenhouse that > used $1500 of propane heat last winter, vs. $8,000 the winter before,
Perhaps your best job yet. Are you the first to do this? >a > 2×4x8′ test box that sat on a roof last winter,
And as I understand, you attempted to make it R-20, but it only performs as if it were R-5… A test box is not much of a ‘creation’ to blow your horn on. > a bubblewall test box,
Ditto. and > my favorite: a simple and general scheme to design an inexpensive 100% solar > heated house that makes inexpensive solar hot water too, using some arithmetic > and NREL solar data, described in a paper physics prof Paul Bashus and I gave > at the World Renewable Energy Congress last June, sponsored by UNESCO, DOE, > NREL, The British Council, etc, and just published in the proceedings by > Pergamon Press. You can see it at http://leia.ursinus.edu/~physics/solar.html. > It will also be published soon in The Journal of Renewable Energy.
This is an idea, not a creation. Many at DOE and NREL would be surprised by your suggestion of their tacit approval of your paper. > This winter I’m working on a 20×32′ air heater for another local building, > and a 12×22′ 100% solar heated building retrofit. I finished the sunspace > frame for that today, and I’ll be doing some insulation tomorrow.
Then log all of the energy inputs, outside temps, inside temps, etc, and let us know the results in the spring. >A scientist? [blah blah blah] > No, an engineer. We have enough solar scientists.
An electrical engineer. You tend to denigrate thermodynamics, the fundamental solar thermal skill. >Case in point. Mr. Pine has, for more than a year, = >repeatedly asserted that with no more than plastic = >sheeting, plastic shade cloth and a 50 watt blower = >he can impart 120F into a water storage device when = >ambient air temp is 50F or below. > Doesn’t take all that. Just some plastic. Of course you have to make sure > the planets are all lined up correctly, etc Let’s try a little thought > experiment, Dan. Direct sun of 300 Btu/ft^2/hr is shining into a insulated box > through some R1 glazing, and the temperature outside is 30 F. Assume all the > heat is lost back out the glazing. What is the temperature inside the box? > (Hint: 330 F.)
This is another example of misapplied arithmetic; there are no assumptions about solar incidence angle, insulation R values, time necessary to reach this ’steady state’ condition, infiltration losts, etc. > And if you attach another insulated box to the back of the first, with some > thermal mass inside, and blow some hot air from the first box to the second > when the sun is shining, and it prevent air from flowing at night, what is > the temperature inside the second box? (Hint: 330 F.)
Insulation losses in the second box would result in a lower temperature. Kids don’t try this at home… The reader is encouraged to employ texts that contain correct application of engineering data, as opposed to relying on Nick’s posts. Imagine if your brain surgeon was a podiatrist that had skimmed through a pictorial on brain surgery. Would you be willing to go under the knife? Cheers, — William R. Stewart http://www.patriot.net/users/wstewart/first.htm Member American Solar Energy Society Member Electrical Vehicle Association of America "The truth will set you free: - J.C. "Troll: A deliberately disrupting, confused and incorrect post (or one posting trolls) to a Usenet group to generate a flurry of responses from people called "billygoats" trying to set the record straight. Other trollers enter the fray adding more and more misinformation so that the thread eventually dies of strangulation. Trolls/trollers cannot be affected
Response:
Daniel, I’d say think again what science is and what makes a scientist. I think you’re being insulting insinuating that Nick is seriously conspiring to destroy your industry or that there are people in your industry with out the mind to evaluate Nicks thoughts on there own. Many people like myself come to these newsgroups not just for some serious discussion but also for a chance to talk about ideas at leasure in the casual hope that there may be some interesting spin offs. I don’t see how your attitude helps anyone, but then again I say "who the hell am I" ? — Marc O’Brien Industrial Refrigeration Mechanic > Andrew my impression is that Nick is a >free minded creator with the >characteristic light hearted attitude. You might >be too heavy and serious >to gain anything out of this thread. Seems to me >we have the business man >rediculing the scientist, type of thing. I’m not >saying you aren’t a >scientist, you’re just from another necessary >nitch in the big picture that >won’t bare much fruit from interaction from Nicks >kind where others would >harvest huge spin-offs. But then who the hell am I >? >– >Marc O’Brien >Industrial Refrigeration Mechanic
I come into this thread late but I
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