Solar Heater For Spa

[forgetg]

Hello all, i live in South Florida and have purchased a small 176 gal spa...works great...I am looking at putting together a solar heater for the unit....i am fairly mechanically inclined, can anyone point me in the right direction, I would like to mount the panel or panels on the roof, and i do not understand how the pumping would work, my unit uses the circulating pump for the high volume jets as well, so i guess I will have to get and install some kind of recirculating pump as well..

thanks from a newbie for any input

Gordon

[Accent]

I saw this online. I have no idea how well it would work, but I'm curious about it myself. Sounds a lot cheaper than the equivilent in PV for electricity, but I don't know much about this stuff. If you learn something, let us know:

http://www.solarhottub.com/

[reallost]

I saw this online. I have no idea how well it would work, but I'm curious about it myself. Sounds a lot cheaper than the equivilent in PV for electricity, but I don't know much about this stuff. If you learn something, let us know:

http://www.solarhottub.com/

well i think there claim it can save you $200 a month is a bit of a stretch. great ideal. im sure in summer it could replace the need for your tub heater. but heating costs would be worse in winter.would it be able to replace your tub heater,if not, do you think the savings it would genrate during the winter would be noticable?

[Accent]

I think your costs/savings would all depend on where you live - how much sun exposure you have - how much electricity you use. My tub is small and efficient and so far it adds about $20 per month to my bill - definitely less than the $200 that the website mentions - but it's still about 2/3 of my electric bill (I use very little electricity). I looked into getting solar electric panels and, to cover my usage, it would cost about $15,000, including the tax credits we are about to lose. Most solar experts claim that solar water heating is much more efficient than solar electric, so the product's claims sound feasible. I called the guy today and I'm going to look into installing this system - I figure it's worth it if I can cut back on my carbon emissions and still enjoy my tub - and certainly a lot cheaper than panels. If I were to eventually save money, than that would be a bonus. If I do it, I'll report back.

[RickJ]

A solar heater might work great during the day, but at night it's not going to be heating your tub. If anything, with all of the exposed plumbing, it might help cool your tub overnight. Then in the morning it would have to heat the tub back up again. This might be okay if you only use your tub in the afternoon. But if you use it after dark or in the morning, you might just be "tubbing" and not "HOT tubbing."

Of course, this is just my opinion, based on no research whatsoever.

However, why not install a solar electric system that has enough power to run your tub in its current configuration? Power the tub's heater and pumps with solar electric power. Put in the batteries to store the power for night-time use. That way, your tub still works great, and you can save money on electricity.

[Hillbilly Hot Tub]

[some people run the tub off a zone. We see it a lot in outside wood stoves in this area. The tubs are their own zone, like a room would be in the house. I am sure it could work the same way if you were adding solar to your house for hot water ect, but heating just the tub would be different. Let us know what you all find out!

[Accent]

why not install a solar electric system that has enough power to run your tub in its current configuration? Power the tub's heater and pumps with solar electric power. Put in the batteries to store the power for night-time use. That way, your tub still works great, and you can save money on electricity.

Solar electric heat is less efficient and more costly than solar water heat. As I mentioned above, it would cost me more than $15,000 for an electric system to cover my usage of about $30 a month. Whereas, if it works, this system would cost between $1000-$2000 to cover my biggest energy user and would eventually pay itself back.

As for the whole night thing, the water gets heated up during the day and then put into the tub. It should stay hot until night if the tub is well insulated, which mine seems to be. You're right that it'd be colder in the morning. In any case, this acts as a supplemental system to the electric tub which would be doing more work on cloudy days.

Anyway, I'm not totally convinced yet, but the math certainly seems good.

[Dr. Spa]

You might want to recheck that solar web site. They list the panel size as 4 feet by 20 feet in one place, then as only 20 inches wide in another. They also list the weight as 19 pounds. No way is a 20 foot panel only weighing 19 pounds.... oh and, NO WAY is a 20 inch by 4 foot panel going to even BEGIN to heat a hot tub. At best, this size panel is 6.6 square feet, and it's probably closer to 6 square feet of usable absorption panel area. Rough estimates are 283 BTU'd hit the earth surface per square foot, per hour. 6 square feet = 1698 BTU's per hour hitting the panel. Lets be WAY OVERLY generous and say you can collect the suns rays for 6 hours per day. This gives you all of 10,188 BTU's of energy per day hitting the solar panel. 10K, BUT WAIT! Nothing is 100% efficient. Sorry, here I don't remember the stats, but I seem to recall solar water heating panels are something like 60%, maybe 80% efficient. Let go 80% for the benefit of the doubt. So now, you can collect about 8k BTU's of energy per day with one of these panels. 8k BTU's.....The smallest gas heater we provide with our hot tubs puts out TEN TIMES this amount of heat, in ONE HOUR.

Before getting into this business, I used to be in the solar industry. GOOD LUCK trying to heat your spa via water. I have 3 (top of the line), four foot by 8 foot panels on my roof. Perfect location and position (hey, I was in the business remember). On the BEST of days, I might be able to heat the 80 gallon storage tank to 180 degrees....and there's very few "best" days throughout the year :-)

[Hillbilly Hot Tub]

What you read on the site were about 2 different solar panels, one was 6 feet by 20 inches 10 square feet 10,000 btus, the other was 4 feet by 20 feet 80 square feet 80,000 btu's. The smaller ones are light weight and made for smaller roofs and they suggest you use 3. Now I am not trying to sell them or say they are all that, just want to point out if you are going to knock something use the correct info.

We have seen homes heated with solar around here, forced hotwater systems and rarley do they need backup, and we have friends, in Hawaii which helps, that heat their hot water with solar with no issues and plenty of hot water. How old are your solar panels, since you have been in this buisness so long, I am guessing they are ollder models. Are the new fangled ones they are coming out with better?

And how about the solar to electric version that is mentioned. Would it produce enough electric?

Wind mills are getting more popular in certain areas out here also!

I am all for alternative energy routes, I just hope they become more cost effective in all aspects.