SPA-HOT TUB...Car engine

[GreenCloud]

Ok..anyone seen or heard of a spa powered by say a  4 cyl. honda engine.

Water heated thru engine block ..pumps into spa



I have energy concerns, cant use electric spa

Friend mentioned some hippy guy in hillside had an engine hooked up..barely hear it idlling away whiel it pumps hot water into spa...maybe also power small aux water pump for jets; )


any ideas?

mayeb find somthing about this in some "off the grid magazine?"

[rpm]

That would be a grossly inefficient way to heat a spa. The water pump on the engine moves about 1/3 the gph you need as well.

If you want an alternative energy spa, try gas or wood for a heat source. You could convert an old gas water heater and plumb it to the spa or gut the heating element and use firewood. I've seen a wood fired spa before using a converted water heater and it worked fine. You just need to start heating the spa about 4 hours before you use it.

Personally, I like my electric spa. I never have to worry about it freezing in the winter, either.

[Ripsnort]

Originally posted by GreenCloud
Ok..anyone seen or heard of a spa powered by say a  4 cyl. honda engine.

Water heated thru engine block ..pumps into spa



I have energy concerns, cant use electric spa

Friend mentioned some hippy guy in hillside had an engine hooked up..barely hear it idlling away whiel it pumps hot water into spa...maybe also power small aux water pump for jets; )


any ideas?

mayeb find somthing about this in some "off the grid magazine?"

I'd say go with a gas-guzzling CO2 emitting 460. That way you'll heat your spa and have a smile on your face knowing that somewhere in the world there is a beetle that is very angry....

[Eastwood]

American understands that he or she is responsible for the decisions that you make."President G.W.Bush

  In that case he should lead by example and throw himself in jail

[Gunslinger]

Originally posted by SomorPlz
American understands that he or she is responsible for the decisions that you make."President G.W.Bush

  In that case he should lead by example and throw himself in jail

Does everything have to be about Bush with you people



Seriously use the 4cyl engine and ricer it and the hot tub out.  Were talking crome trashcan muffler find some place to put a wing, baddass stereo, some dubs.  You'd be stylin.

EDIT:  and I don't think you could use the water pump except to move hot water.  You'd probably have to hook up a seperate water pump to the output shaft of the engine. but like RPM said it'd be horribly inefficient.....unless you're going for the "monster house" look.

[capt. apathy]

I put one of these on my spa.  it works great, easy to install and no problems at all.

http://www.poolproducts.com/pdf/raypak_versa_055_manual.pdf


  the spa would draw 45 amps of 220v with the electric heater and jets on high.  no good for me with a 103 yr old house and 60 amp mains.

  with the gas heater I can run lights, jets on high, air-blower, and air-heater and only draw 8 amps off one leg of the 220 and 10.6 on the other.

no major modifications to fit it up either.  just cut the pipe between the pump and the control box and electric heater, route it from the pump, out the side to the gas heater and back in to the electric heater.  if you have a 1 1/2hp or larger pump you will also have to plumb in a bypass valve so the heater doesn't cause to much restriction.  no need to alter the tubs controls, the heater has it's own thermostat, set it to the desired temp and turn the tubs electronic heaters to off (or anything below the temp of the gas thermostat).

if you have no gas line they also make a the same unit fitted for propane.

you'll spend about $30 for plumbing, $15-150 to run the chimney (depending on indoors or out and how close you position the heater to buildings), and heater goes for about $625-800 new (depending on how good of a haggler you are) but if you are patient you can find a used one for about $200.

 if you have a larger tub you can even go with a small pool heater, they are more common and cheaper to buy used 100,00 BTU or less would be best for a tub <500 gal  but the 150,000 btu's are way easier to find cheap.

[capt. apathy]

Originally posted by rpm

Personally, I like my electric spa. I never have to worry about it freezing in the winter, either.

with the gas heater I can fill it with < 60 deg water at 5pm and be soaking at 103deg before 9:00PM.  I get almost 12 deg per hour, haven't seen many electrics do better than 4 or 5.

much cheaper to run.

[eskimo2]

After I temporarily heated my unattached, uninsulated, unheated garage with a V-8 while I needed to paint a car, my old roommate took it one step further the next year and used an auto engine to heat water in a fish tote turned into a Jacuzzi.  I had moved out when he did it and never saw it first hand, but he said that it worked very well.  

Give it a try; it doesn’t get anymore redneck than that!

eskimo

[rpm]

Originally posted by capt. apathy
I get almost 12 deg per hour, haven't seen many electrics do better than 4 or 5.

much cheaper to run.

I get 6 per hour with mine. It definitely costs more, but with the rising cost of gas it's getting closer. I've considered a solar water heater for the house. Pipe it in before the electric heater and get a free 40-50 gallons before the element kicks on. You could pipe the spa into the heat exchanger very easily.

[Russian]

Originally posted by SomorPlz
From Vacaville

I'm also from that town... I do not see 'local' simmers often.

[mora]

Around 1/3 of the total energy of the fuel is tranferred into heat in a 4-stroke engine. Around 1/3 of that is carried away by the motor oil. That leaves us 2/3 from 1/3. From what is left maybe half is emitted to the air straight from the engine block, and the rest through the cooling system. So roughly we would be talking about 10% efficiency.

[capt. apathy]

Originally posted by rpm
I get 6 per hour with mine. It definitely costs more, but with the rising cost of gas it's getting closer. I've considered a solar water heater for the house. Pipe it in before the electric heater and get a free 40-50 gallons before the element kicks on. You could pipe the spa into the heat exchanger very easily.

I heat our pool with a solar heater.  it cost me about $75 to build.  in an average year the pool hits about 85 deg by mid-June, by the 2nd or 3rd week in July I have to cover about 2/3 of the heater to keep the pool under 90 deg.

mine sits on the roof at a 45 deg incline.  it's a 4' x 6' frame made of 2x4's with a plywood bottom.  I lined it with the aluminum clad sheet-foam that they use under vinyl siding, painted the inside black, and piped it with 3/4 PVC (also painted black) in a zig-zag pattern so it constantly climbs through the pipe to make no traps. I covered it with a pair of clear tempered glass shower doors that I picked up at a home salvage store for $10.

I put it in-line on the 1 1/2" pipe that returns to the pool from the pump/sand-filter unit.  when the 1 1/2" gets to the heater it switches to 4" pipe that runs up the underside of the heater (also with the back and forth pattern) with the final piece mounted above the top edge of the heater.  the 3/4 line that runs through the heater T's off before the 4" and comes back in just after.

the reason for the 4" bypass is that it works like a tank.  when the pump isn't running the convection will cause the water to circulate up through the heater, pulling cooler water down through the 4" as it dumps the hot water into the top.  with this set up I only have to run the pump for 5 minutes out of every 20, from about 10 am until just after dark.  on a clear sunny day, during the 5 minutes the pump runs the return water is 5 deg hotter  than the water going up at about 60 gpm

before I figured out the bypass we had the pump breaker blow some time around noon and before 1pm the heater had become hot enough to  put a big sag in any unsupported pipe and actually go soft enough at the top for the weight of the water to suck the pipe flat.

with enough insulation, one or 2 of these could easily heat a hot tub.  figuring out some sort of thermostat controls so that keeping the tub at 103 wouldn't be more trouble than it's worth would be the big trick though.

[DREDIOCK]

Originally posted by SomorPlz
American understands that he or she is responsible for the decisions that you make."President G.W.Bush

  In that case he should lead by example and throw himself in jail

and exactly what does that have to do with spas?

LMAO and they say BUSH is an idiot

[DREDIOCK]

Just get a big cast iron Cauldren fill it with water and build a big fire underneith.

While your at it bring some potatoes, onion and carrots in ther with you;)

[BigGun]

i just put pool in with a spa...spa is pretty good size..

to heat spa, has hooked up 400,000 btu gas heater, can heat that sucker from 55 to 102 in maybe 15 minutes...can also heat the pool, but havent tried that yet.