Eco Spa

[Aquaholic]

Hi all. New member here. Just acquired an old Eco Spa hot tub (project/non runner). The guy I got it from said that the blower motor also provides the heating for the water through a heat exchanger/heat recovery system. Is anyone familiar with this set up? Can’t find any information online. Many thanks.

[bud16415]

I don’t know about your brand of tub. I believe some companies tried to recover motor heat into the water with different ideas.

Most new tubs now I believe don’t have blowers for air bubbles and rely on water jets that admit air into the water stream. My tub has a blower along with two pumps that have different speeds. We like the blower and use it mostly in the summer, as it tends to cool the water. If I have the tub set to 104 in the winter and we have friends over not used to hot tubbing they sometimes feel it is unbearable and I will lower the temp to say 102 and run the air gets for a couple minutes and the tub is more to their liking within a half hour.

I’m no expert on heat exchangers in tubs, but I think they are just a supplement for an electric heater. I don’t know how much help they really give.

[Aquaholic]

Success! I have the motor running. I bypassed the control pad and it came to life. The water is heated through a stainless coil which is wrapped around the motor and insulated with a neoprene jacket. Think I’ll need to add an additional form of heating as it’s taken an hour to increase the water temperature by just one degree. Might be warm enough to use in about a week!

[wmccall]

Success! I have the motor running. I bypassed the control pad and it came to life. The water is heated through a stainless coil which is wrapped around the motor and insulated with a neoprene jacket. Think I’ll need to add an additional form of heating as it’s taken an hour to increase the water temperature by just one degree. Might be warm enough to use in about a week!

Is there a lid on it? what is the temp where you live?  For this type of tub 1 degree per hour maybe the limit! (Consider this a low reliable answer) Most conventional hottubs with 110 or 220v heaters get around 4-10 degrees and hour, but I know this eco type gets less.   

[Aquaholic]

No lid yet - it’s on the ‘to make’ list! I put a sheet of ply over the tub for the test. Coming into winter here so it’s got a challenge on its hands. Planning to plumb in a wood burning water heater to assist with the heating.

[bachman]

No lid yet - it’s on the ‘to make’ list! I put a sheet of ply over the tub for the test. Coming into winter here so it’s got a challenge on its hands. Planning to plumb in a wood burning water heater to assist with the heating.

Sounds like a fun pre winter project. Where are you located as per seasonal temps ?

We've got our first spa and have it going about a week now. It's has a nice thick cover (we are in Colorado) but on a budget, you may be able to fabricate something that is insulated and get you by for a while. Maybe a tarp type material with insulfoam sheathing or something. Sandwich it in there and anchor it down so it won't blow off.

[Aquaholic]

I’m in the U.K. On a budget myself, hence the wood burning option. Hoping it’ll heat the tub up in a couple of hours. Will post some results here once it’s running.

[Aquaholic]

Update - I’ve built a wood fired water heater from a gas cylinder with copper tube coils installed at the top. Utilising the drain outlet tap, I have taken a water feed to a small central heating pump which circulates the water through the heater coils and back into the main tub through a spout (a bit crude but it’s only for test purpose at this stage!)

I fired up the heater at 9am yesterday and the water was 14C. With the fire running low on a number of occasions during the day the water had reached 30C within 13 hours. Left without heat overnight the temperature has dropped to 27C. Not too bad considering there’s only a makeshift cover and no insulation on the water pipes.

Fire relit hoping we’ll reach optimum temperature to use the tub tonight.