Is a Solar Bear heater worth the money?

[cubbybeave08]

I want to buy an above ground pool solar heating system that is simple to install and give me a few extra degrees of warmth when I need it...especially in the spring...Last Spring was first year with pool and we had a cool spring...I want to take that 70-72 degree temperature and kick it up to 78-80 degrees. Do these pool side solar systems such as the Solar Bear or Sungraber systems work well. The pool store says they do add about 10 degrees...But I don't buy everything they tell me...Anyone here use them? Do they add to your swiming season? If so how much...I have the perfect back yard for it...I get Sun from 9 am to 5 pm...Any help would be great.

 

[mas985]

The heat gain you will get from any solar system is proportional to the size of your panels. The larger the panel area, the faster the pool will heat.

I have about 87% coverage for my panels and I can get about 8 degrees temp rise per day with 10 degree during the hotest part of the summer. However, I will lose about 6-8 degrees overnight without a cover and 3-4 degrees with a cover.

Any panel system will help heat the pool, you just need to decide on how many panels you want. If you plan on using a cover, then you can get away with less panels. If you are like me and don't use the cover very often, then you will benefit from more panels.

 

[launboy]

I'm not sure what Solar Bear panels cost, but I think the 2x20 ones were about $120.00 at my local pool store. I went on eBay and bought two Sungrabber panels from an online pool store that sells on eBay. With shipping they only cost $160.00.

The Solar Bear panels advertise that you can control the flow through the panels with a valve in one of the headers. I don't see this as an advantage for two main reasons, first is because I have a bypass for the panels by the filter. I believe every solar setup should have a bypass so you can turn off the flow to the panels when the pool gets warm enough or during bad weather.

HTH,
Adam

 

[cubbybeave08]

I'm not sure what Solar Bear panels cost, but I think the 2x20 ones were about $120.00 at my local pool store. I went on eBay and bought two Sungrabber panels from an online pool store that sells on eBay. With shipping they only cost $160.00.

The Solar Bear panels advertise that you can control the flow through the panels with a valve in one of the headers. I don't see this as an advantage for two main reasons, first is because I have a bypass for the panels by the filter. I believe every solar setup should have a bypass so you can turn off the flow to the panels when the pool gets warm enough or during bad weather.

HTH,
Adam

The one I am looking at sells for between $230 and $299...it is a 4' x 20' pannel. I am going to put it on the back side of my pool set at a 45-50 degree angle...This is the part of my yard that has the greatest sun exposure...there are no trees there at all after 9 am and until about 5 pm...I have a 24' round AGP...This model has the bypass built into the pannel itself...I see this as important because as it gets really hot out...We don't like the pool water to be like bath water...but it took us almost til July to get pool up to 78 degrees becasue we had a very cool May and June...

 

[JohnT]

I'm south of Bloomington, which no doubt is warmer than your location, but hopefully the info is useful. This was my first year with solar. I was very pleased. 20X36 IG with 192 sq-ft of south facing panels.

I found it easy to keep the pool at 90 from around the 20th of May until 28 September with a solar cover whenever the weather cooled off or the water got too warm. This essentially corresponds to the time when the weather was warm enough to swim. Actually, it turned cool early in September, and I almost gave up on the pool. I left the cover on for several days and ignored the pool, and when I went to check on it the water was 96.

The angle isn't really needed IMO, because the sun is overhead or even slightly to the north of us during swimming season. Once the sun gets far enough south that you could benefit from the tilted panels, the short days and cool air temps end the swimming season.

 

[cubbybeave08]

I'm south of Bloomington, which no doubt is warmer than your location, but hopefully the info is useful. This was my first year with solar. I was very pleased. 20X36 IG with 192 sq-ft of south facing panels.

I found it easy to keep the pool at 90 from around the 20th of May until 28 September with a solar cover whenever the weather cooled off or the water got too warm. This essentially corresponds to the time when the weather was warm enough to swim. Actually, it turned cool early in September, and I almost gave up on the pool. I left the cover on for several days and ignored the pool, and when I went to check on it the water was 96.

The angle isn't really needed IMO, because the sun is overhead or even slightly to the north of us during swimming season. Once the sun gets far enough south that you could benefit from the tilted panels, the short days and cool air temps end the swimming season.

John T...thanks for the information...I see what you are saying about the angles...You are right the Sun is pretty much over head from May to mid August...I might however, do something where I can adjust the angle a little bit...because this far North...25 miles from lake Michigan...our sun starts to head south a little sooner than yours might...Usually by mid to late august I would need to maybe angle things a little bit...

 

[amjohn]

I am in the research stages for a solar heater. I have been looking at FAFCO Solar Bear heaters - the two inch header I think are an advantage,and I have a large enough pump to handle that. Another brand I noticed is EZ Heat. http://www.solar-components.com/poolheat.htm
Also, more info on EZ-heat and general sizing: http://www.harterindustries.com/swimmin ... g_syst.htm
Anyone have any knowledge of these?
Also, is there any reason why 4 foot wide panels would be better than 2 foot wide panels- assuming the same surface area?
Considering mounting angles: I found this chart interesting- a link from another post in here somewhere: http://www.engineeringtoolbox.com/surfa ... _1213.html
We are at 33 degrees latitude - considerably south of Indiana. Since we are looking to maximize end season heating and don't need middle of the summer heating (actually need cooling then) , this chart seems to indicate that 30- 45 degrees bank would do this. However, I have also seen the rule of thumb of subtracting 15 degrees from your latitude (northern hemisphere) and having that be your bank angle. Anyone with any knowledge in that matter?
We will be putting our panels on the ground - roof is too far away from pool and we have clear ground around the pool - plus we would have less to mow. We will start just flat on the ground, but am considering having a set up where we can angle the panels in the spring and fall to maximize either end of the season. The air temp is warm enough to swim April - Oct here, and we could have swam last week if the pool water had been about 10 degrees warmer- we had record highs of 86 degrees in early November!

 

[mas985]

If you are trying to maximize heat at the equinox (apr, oct), then you need to put the panels at the same angle as your latitude off horizontal. So at the equator, they are flat. At Lat = 33 degrees, you need an angle of 33 degrees.

If you want to maximize the heat for June 21st (summer soltice), then you subtract 23 degrees for the Earth's tilt. There is about a 8 degree delta offset for each month off end of June which is probably where the 15 degree offset comes from (+- 1 month). So an approximate formula is

Angle off horizontal = Lat - 23 + n * 8

where n is the number of months away from June 21st where you want maximum heat.

 

[kjcole]

I must be missing something because that formula yields some pretty large angles if the *8 part is correct. E.g., for my neck of the woods (Cedar Rapids ~ 42 degrees north) (42-23 + 0) X 8 = 96 degrees. Clearly, I'm doing something wrong.

ooops, I get it (42-23) + (nX8) = 26 if n=0 etc
Forgot my 7th grade math (order of operations)

Kelly

 

[cubbybeave08]

If you are trying to maximize heat at the equinox (apr, oct), then you need to put the panels at the same angle as your latitude off horizontal. So at the equator, they are flat. At Lat = 33 degrees, you need an angle of 33 degrees.

If you want to maximize the heat for June 21st (summer soltice), then you subtract 23 degrees for the Earth's tilt. There is about a 8 degree delta offset for each month off end of June which is probably where the 15 degree offset comes from (+- 1 month). So an approximate formula is

Angle off horizontal = Lat - 23 + n * 8

where n is the number of months away from June 21st where you want maximum heat.

So this would also provide maximum for May as well if i am looking for maximum heat through September, my angle would be 50.6 Degrees...if correct than angle of the sun on its way back south in the latter part of the summer/ fall would be the same on it way northward in the late spring summer...Correct

my lat is 41.something more than .5...so i am using 42-23= 19/3=6.33333*8=50.666 which is what I estimated in my original post.

Am I correct that you are actually dividing by N not adding as it looks like...

Also someone said that they needed cooling in the summer time...due to being so far south...i have read that the Solar bear also left running during the night would have the same effect...water running through the panels has the effect of evaporating out the heat without evaporating the water...You could leave solar blanket on the pool...and it would cool water as long as you left pump running...

 

[cubbybeave08]

I must be missing something because that formula yields some pretty large angles if the *8 part is correct. E.g., for my neck of the woods (Cedar Rapids ~ 42 degrees north) (42-23 + 0) X 8 = 96 degrees. Clearly, I'm doing something wrong.

ooops, I get it (42-23) + (nX8) = 26 if n=0 etc
Forgot my 7th grade math (order of operations)

Kelly

Kelly...regardless of order of operation...N=0 N*8 would be 0...Better recheck...

 

[mas985]

cubbybeave08 ,

Maximum heat at September 21st is 3 months from June 21st and therefore N=3. Three months before or after June 21st have approximately the same sun angle off the horizon so it doesn't matter. Therefore, the maximum heat for either March 21st or September 21st is basically the equinox so the angle of the panels is about the same as the Latitude.

Also, for the formula I gave, order of operations must apply so multiplication is done first. Therefore, for the equinox case:

Angle off horizontal = 42 - 23 + (8*3) ~ 41 degrees. (note; it is 8 degrees/month off soltice so you must multiply N by 8 to get degrees from soltice).

Remember too that the sun's angle varies over the day so this really only optimizes the angle for the sun's highest angle for the day which is why it really isn't all that important to get it exact and you might actually be better off with a slightly shallower angle. Ideally, you really want to optimize the panel position to minimize the angle of incidence over the entire day. This isn't easy to do. To do it properly, you would have to integrate over all of the incident angles during the day and take into account the run time of the pump. Even then, temperature variations durinig the day have an effect so pointing the panels slightly to the southwest and runing the pump more in the afternoon will help heat gain as well. Depending on the angle pointed, this will also affect the panel's angle off horizon.

However, the formula I gave should get you pretty close so don't worry about being too accurate.

Another option is to lay them flat and have more panels (~1.3x) to compensate for the angle of incidence.

 

[kjcole]

Duh! clearly I meant N=1 (actually not, but this makes me look less stupid).

I must be missing something because that formula yields some pretty large angles if the *8 part is correct. E.g., for my neck of the woods (Cedar Rapids ~ 42 degrees north) (42-23 + 0) X 8 = 96 degrees. Clearly, I'm doing something wrong.

ooops, I get it (42-23) + (nX8) = 26 if n=0 etc
Forgot my 7th grade math (order of operations)

Kelly

Kelly...regardless of order of operation...N=0 N*8 would be 0...Better recheck...

 

[cubbybeave08]

Duh! clearly I meant N=1 (actually not, but this makes me look less stupid).

I must be missing something because that formula yields some pretty large angles if the *8 part is correct. E.g., for my neck of the woods (Cedar Rapids ~ 42 degrees north) (42-23 + 0) X 8 = 96 degrees. Clearly, I'm doing something wrong.

ooops, I get it (42-23) + (nX8) = 26 if n=0 etc
Forgot my 7th grade math (order of operations)

Kelly

Kelly...regardless of order of operation...N=0 N*8 would be 0...Better recheck...

didn't want to have you setting up at the wrong angle and having cold water next spring/summer...That would be bad!!! :grrrr:

 

[amjohn]

So, for me angle=latitude
Original question about brands- Fafco Solar Bear (and Harter Industries Ez-Heat which seem very similar)- are they worth the extra money over sungrabber (which seems to be the cheapest brand that is readily available)? The main difference I have found is that those more expensive brands both have 2 inch headers, as opposed to 1.5 inch headers in the Sungrabber. Also, if you get the right models, the panels are a single 4 foot wide panel with rather than qty(2) 2 foot panels separated by a hose/connector. Does this give an improvement in performance?

Also, John T and mas985, what brand(s) are your panels?

 

[mas985]

I have flexible EPDM panels made by SunTrek. I think that they are mainly made for roof top installations since they are not self supporting.

Also, 2" headers will have a little bit less head loss than 1.5" header. As far as efficiency for the two widths, there is probably not too much difference as long as the total sq-ft is the same. So the narrow width will probably take up more space to get to the same sq-ft size.

 

[cubbybeave08]

Mas...question...
If because the Fafco solar bear is flexible...couldn't rounding it slightly as I mount it on a platfrom due to it's twenty foot length also help in catching the suns more direct angles over the course of the day...my exposure is directly south by slightly southwest...in this case rounding the layout rather than keeping it in a straight line would follow more of the eliptical rise and fall of the sun wouldn't it?

 

[mas985]

Mas...question...
If because the Fafco solar bear is flexible...couldn't rounding it slightly as I mount it on a platfrom due to it's twenty foot length also help in catching the suns more direct angles over the course of the day...my exposure is directly south by slightly southwest...in this case rounding the layout rather than keeping it in a straight line would follow more of the eliptical rise and fall of the sun wouldn't it?

I think doing that could actually be counter productive because you would be reducing the heat transfer at the hottest part of the day. That is even more important at equinox since the heat duration will not be very long. Heat transfer through solar panels is not only dependent on the angle of incidence of the sun but it also depends on the ambient air temperature. The lower the air temp, the more heat is lost by both the panels and the pool. So really, you want to optimize the pointing of the panels, assuming you can, to hottest part of the day to maximize heat transfer. That is usually after the highest elevation angle of the sun so 1-3 pm.

I would make it easy on yourself and just mount the panels where it is convienent and not worry too much about pointing the panels. If you can get them on an incline, that will definitely help for lower sun angles but air temperature is likely to be much more important during spring and fall and will probably dictate how warm it will actually be able to get the pool.

 

[cubbybeave08]

I thought about buying three or four wooden saw horses...building a light frame off of them and then cutting the front legs off at the appropriate height to get the right angle that i am looking for...I think this would he the easiest way to do this...Not too expensive...keeps them below the pool level..so they cannot be seen from the deck or the rest of the yard...and it also keeps them off the ground so the dog doesn't eat it...Thanks for all your advice...

 

[learthur]

Here is an alternative solar water heating idea. If you live in an area with clear (few clouds) in the sky such as Denver, or don't have the surface area to spread out all the panels, this may work for you.

http://www.acrosolarlasers.com/

I haven't tried these, but the science seems sound.

I don't think parabolic reflectors do as well in climates with diffuse overcast sunlight as flat solar panels.

--Lee