Heat my hot tub - what do you think?

[yukiginger]

Hey, folks, I actually researched the wood-fired hot tub heaters (the external ones) a while back, but look what this guy on my local Craigslist has: (broken link removed)

It sure would help with my winter electric bills due to running the hot tub.

MarkG

 

[Harley]

I'm sure it world probably work, but I'm not sure I'd really like something like that too close to the hot tub (short stack, and probably a little on the smoky side.), the other down-side I see would be having to run it all the time in colder weather just to keep the tub from freezing (unless of course you would use something like that just to boost the temperature for use, and have an electric heater running to keep the temps up above freezing).

 

[karl]

I have a hot tub and I have thought about doing something like that many times. It won't work well. Either you have to keep a fire going in it almost all of the time or you will have to still use the electric heater on the hot tub. Also, you would have to either disconnect and drain it after each use or leave the pump running on it all of the time. You might be able to use the hot tub pump to circulate the water through it, since the hot tub pump runs all of the time. If you did that, then you wouldn't have a way to control the temperature in the tub and it would get too hot. 104-105 is nice but 107-110 and you're in the ER. Besides, who wants to go build a fire and then wait an hour or two before going tubbing? I leave mine hot all of the time. That way, when I have a lady friend up we can just run out there and hop in. This winter I'm hoping we can dry off on a blanket in front of my new fireplace insert.

 

[Mr_Super-Hunky]

FYI:

The newer hot tubs utilize the heat generated from the spa motor to maintain the heat in the tub once it is heated up. You can actually keep a tub at 104* all month long for around $8.00 per month. This of course is assuming proper under tub insulation and a thermal cover as well.

 

[keyman512us]

I'm sure it world probably work, but I'm not sure I'd really like something like that too close to the hot tub (short stack, and probably a little on the smoky side.), the other down-side I see would be having to run it all the time in colder weather just to keep the tub from freezing (unless of course you would use something like that just to boost the temperature for use, and have an electric heater running to keep the temps up above freezing).

Harley,

Seeing as we both live in Massachusetts, we would never be able to get away with it...then of course too, in 2008 when 'outdoor wood burning appliances' are banned in the state of Massachusetts (legislation State Sen. Brewer D-Barre is currently working towards thanks to all the 'crybabys' raising a stink about OWB's or anything remotely close) it would just be another trinket to list on craigs list or ebay... lol

 

[littlesmokey]

Ever consider adapting a pellet stove? With the control of the fire and the ease of fueling you could set it on low and maintain your heat, crank it up with increased demand. Just don't get the hopper wet.

 

[karl]

super hunky is right. I don't even notice mine in the electric bill.

 

[yukiginger]

Wow, I had no idea newer hot tubs were that efficient! My hot tub service guy told me my tub probably costs $40-$60 a month to run in the winter (western NY). It is an older one and does not have the extensive insulation the new ones do, either.

The only way I would use an external wood-fired heater would be to hook it in-line with the existing electric heater, so that would always maintain the temperature in the tub and the system linked to the wood heater, but now I will begin to investigate the efficiencies of the newer tubs and worry no more about the costs of running one (once my current one gives out).

Thanks.

MarkG

 

[Highbeam]

I am on my second home and have installed my second hot tub this winter. We love it, even after several years of owning one. Many many folks burn out and after one year get tired of them. Anyway, the tubs do require a huge electrical service between 50 and 60 amps of 220 volt power so they are capable of using 10,000 watts when everything is running at once like heater, pumps, blowers, lights, ozone, etc. My first tub was bought new in 2000 and this second larger tub was higher quality but larger and made in 2004. In both cases the electric bill went up no more than 10-15$ per month in the winter.

Ah yes, sitting in the tub at night with a full moon and 6" of snow on the ground while sipping bourbon and catching wiffs of wood smoke. We keep our tub at 100 degrees to allow hours of soaking time and so that the small kids can join us.

 

[Mr_Super-Hunky]

The only chemicals you will need is some bromine tablets and possibly some baking soda now and then .

 

[Highbeam]

I use the sodium dichlor which is chlorine instead of Bromine for sanitation and then sodium carbonate which isn't quite baking soda (missing a C) to raise the pH as it slowly goes down with use.

Chemicals are pretty cheap and easy. Once you get a rhythm you don't even need to check the chemistry very often at all. Maybe every couple of weeks.

 

[keyman512us]

The only chemicals you will need is some bromine tablets and possibly some baking soda now and then .

Yeah, I'm not a big fan of chlorine personally either. Apparently though, it all depends on the manufacutrer and what kind of "Corporate alliances" they have.

Therma Spas (the ones you see plastered on the TV these days) apparently doesn't want people to be in the 'Baquacil Camp' though. Their owners' manual outlines 'chlorine only'....

hhmmm...Whats' up with that???

 

[begreen]

How about using ozone filtration to reduce chemical use?

 

[Mr_Super-Hunky]

FYI:

"sodium dichlor" is chlorine!, its just a much lower percentage (in the 50% range) so it does not have the acidic qualities of "regular" (trichloroisocyanuric acid) chlorine.

Sodium dichlor is fine to use in a spa, however, most people prefer the "feel" and especially the semi-sweeter smell of bromine.

"Bacuacil" has been removed from the market here in AZ many, many years ago and was blamed for many filter problems as the amonia in it had an adverse reaction to some of the plartic filters.

An "Ozone generator" is good in theory, but usually must be supplemented with another sanitizer as they cannat keep up with heavy bather load.

There are lots of sanitizers out there and even exotic ones, such as potasium monopersulafate, but if things get to complicated, the spa owner will just get frustrated.

SO, to keep it simple, you must do two things; 1.) keep an accurate amount of sanitizer in the spa to kill any bacteria. Use only test strips (not liquid reagents) to test for the proper amount. and 2.) try to keep your alkalinity and PH accurate as too low alkalinity will beome corrosive on metal parts such as your heating element.

Bromine tablets and some baking soda is usually all you will need...(and some test strips). Should your alkalinity be fine (around 100ppm), but your PH too low, you could just add a bit of soda ash to only raise your PH. You will find that your PH and Alkalinity will usually go up and down together which is why baking soda (sodium bicarbonate) will raise both together. Soda ash will only raise PH, not alkalinity.

Keep in mind that the absolute worst thing you can do to a spa is to have corrosive/aggresive water in it as it will eat anything metal, (usually a very expensive heating element). Buy a pack of test strips and keep your chemistry as follows:

Bromine level: 1.0-3.0....(light usage-heavy useage).
PH: 7.2-7.8
Alkalinity: 80-125 ppm. preferably around 100.

Try too drain the spa once a month for heavier usage, and every several months for lighter usage. Best way to do this (if it doesnt have a drain) is to buy a small submersible pump, or for free, just siphon the water out.

Also, its a very good idea to keep a tennis ball or two floating in the water as the fuzzy coat will do a great job in trapping lotions and oils that are in the water. When it becomes a bit sticky, throw it out and put in a new one.

Hope this helps.