Inflatable hot tub

[Declan52]

Has anyone got/used one of the inflatable hot tubs before. Am looking in to buying one but never had the pleasure of using one before.

Next decision is then to build a deck for it to sit on or dig a hole and sink it. Cost wise probably not much difference between the two. And if I dig a hole and shutter some concrete I can put a temp bench in for a sunken seating area and put a chimea in the inshot where the pump and heater will sit when the hot tub is in place, so will have an extra place to sit outside and enjoy the rain. Drainage will be easy as storm drain for the house will be pretty close and can get power from the shed.

Oh and before someone else says it I already have a large bowl for all the car keys!!!

Edited September 2, 2016 by Declan52

[K78]

They look a bit tacky. 

 

Noticed a few new on ebay recently for half the RRP. 

Edited September 2, 2016 by K78

[ProDave]

There was a spate of "sheds with hot tubs" here when Tesco were selling them very cheap.
 

[Declan52]

That was my original plan but after I cut all timber left over from my build and my trees and i need  space for a pallet of pellets plus a work bench, golf clubs kids bikes I couldn't fit a bucket of water in the shed.

[slidersx200]

I know a guy who hires them out. No idea how far from home he takes them, but they start at £80 for three days. Try before you buy?!

 

 www.rubbahottub.com

[TerryE]

Don't know anything about inflatable hot tubs, and in fact this post was when I learnt of their existence. But having watched a couple of YouTube videos they look like a good budget way of having a hot tub. However, we did have a conventional hot tub for nearly 10 years so I do know about the ins and outs of these. We liked ours and the kids thought that it was great when they were growing up. There's nothing like watching our pub next door's New Year fireworks display sitting in the hot tub with a bottle of three of fuzzy. But some things that you need to consider:

• They are bloody expensive to run.
• A typical hot tub will take 2 tonnes of water which you need to replace every month or so at least.
• You have to heat up 2 tonnes of water 20-35° depending on season each refill. Do the maths. This takes over 24 hours.
• You have to keep the thing at or near running temperature, because you don't want to have to plan your dips 24 hours in advance. Again estimate some rough U values, etc. and do the maths.
• Having that amount of water at body temperature is a fantastic vat for breeding at sorts of nasty buggies so you need to use some fairly nasty chemicals to keep them under control, and these linger on your skin, so you do need to shower when you get out.

For the last few years I used to heat it and cycle the pump only during the economy 7 window and heat it to 40° then let it cool during the day. This meant it was as temp for a morning dip, and you had to boost it for an hour before getting in if you wanted an evening one. But this pretty much halved of running cost. When I sold it our electricity bill pretty much halved and there was a noticeable drop in our water usage.

 

Your hot tub will have a far greater energy footprint than your house.

 

Even so we and the kids really enjoyed it and in the days when I was earning good money, we could afford to run it.  If you want to try one, then an inflatable one seems to be a fairly cheap way of dipping your toe into the water.

 

Note that the inflatable tubs are usually a lot smaller than traditional ones and only take about a tonne of water.

Edited September 3, 2016 by TerryE

[Onoff]

Two mates have one. The first has a "proper" one costing several thousand at the time. He's quoted all the above reasons about it's running costs and cleaning. It's comfortable enough. Less so when he tells how you have to add chemicals to counter the washing powder residue in swimming cossies or something to stop it foaming / scumming up.

 

His brother has just bought one of the square, Lazy Spa inflatable types for less than £500. Imo it looks seriously uncomfortable. Where's the sculpted seating you get with the proper ones? It looks a lot less inviting than a proper one and even those I can take or leave. Tbh I don't cherish the thought of a bath with anyone and then you have to shower afterwards anyway to feel clean. 

 

Other people's flaky bits & scum.....yuk! 

 

The missus is mad keen on us having a proper one some day and I don't think I'd ever get her out of one. We just had out own private one on the deck on holiday and she lived in it.

 

Hoping she'll forget about having one when I get the spa bath plumbed in!

[PeterW]

I have a mate in the leisure industry and they nickname the hot tubs in the hotel the "bucket of skin soup...."

 

My brother had one - not cheap to heat and if you buy branded chemicals it gets pricey. You can get cheaper stuff which is just as good. Apparently if you fill them with rainwater it's slightly better, I've also heard the cedar ones keep the water cleaner for longer although a wood fired cedar hot tub is a long way off for me ..!!!

[SteamyTea]

I used to supply and build, spa baths.  The worse job I ever had to do was clean out the DE filter from the Sheffield YMCA leisure club.  I still don't like to think what those young men got up to in it.

One we fitted in Shrewsbury leaked, the shop below was not happy.

Two minutes in the one at Bedford Leisure Centre (the one mention frequently in the Brittas Empire) caused my legs to go very rashy.

http://www.skinsight.com/adult/pseudomonasFolliculitisHotTubFolliculitis.htm

 

Vile things that are best avoided.

Edited September 3, 2016 by SteamyTea

[Onoff]

Being of the "could I" rather than the "should I" school, I've mulled over making one.

 

Tentative thoughts are to start with a level base (either below or at ground level) with a scaffold pole set in it dead vertical as a datum. Then build the basic structure from Celcon blocks set to give a circular form. Line with thick EPS or PIR like 300mm thick. Then using the central pole form a giant hot wire cutter to rotate around the pole and form a continuous seat profile. Fibreglass matting thereafter.

 

Haven't figured the jets yet...

 

[SteamyTea]

You can buy the jets, there are two sorts, water and air.

Its is not the jets though, it is all the pipework that needs to be leak free when making one 'back to front'.

 

You can buy a shell at a reasonable price if you hunt around, a lot easier.  Try SpaForm in Southhampton (if they are still going).

[joe90]

My mates wife just bought one and we tried it, for the money ( Tesco) it was great fun for an hour but I dread to think of the running costs.

[Onoff]

46 minutes ago, SteamyTea said:

You can buy the jets, there are two sorts, water and air.

Its is not the jets though, it is all the pipework that needs to be leak free when making one 'back to front'.

 

You can buy a shell at a reasonable price if you hunt around, a lot easier.  Try SpaForm in Southhampton (if they are still going).

 

 

It's just another pipe dream.....

[Declan52]

Think I might hire one out first and see what it's like and keep an eye on the electric meter and try and figure out rough running costs.

I also was looking at the wooden tubs that have a stove attached to heat the water but they are near £1500+ and they are permanent. The blow up ones can be took down and put away which would be a positive for me.

 

[Ferdinand]

I went to a showroom in Stockport when I was looking at cars recently.

Prices went from a couple of thousand to about 15k.

 

More realistically - is it practical substantially to heat these by changing part of the water for hot water from heat stored in eg a Sunamp, or using a gas boiler - which will be about 20% of the cost of electric, rather than treating it as an expensive kettle.

 

Running some numbers.

 

According to this calculator, to heat 2000 litres of water by 15C takes 35.2 kWh.

 

A 4 cell Sunamp PV stores 10 kWh. A Sunamp stack can store up to 100kWh, though it presumably needs a stonking solar array to warm it up. But this looks like a good use for summer solar energy :-).

 

According to the brochure Sunamp output *power* for a 5kWh two-sell Sunamp PV is 35kW, which suggests that it can go from full to empty in 5/35*60 minutes. Or if we have enough heat batteries (ie seven) that there will be no issue with delivering enough heat to the hottub in 1 hour - provided we can supply enough water to carry the heat. ie the Sunamp power output is not a pinch point in the system.

 

If the water Sunamp is delivered at 50C, to match domestic hot water temperature, I make that half the water will have to be changed in the hot tub to raise the temperature from 20C to 35C.

 

Or 1 cubic metre of hot water would be required in Terry's example, which is 1000 litres. At 12l / minute volume for a normal hot tap that is 90 minutes anadi (as near as damn it).

 

Which looks to me to be a within-spitting-distance-of-being-practical way substantially to cut the cost of heating a hot tub with no loss of useability. And it would be easy to reheat when people are in it. And there would be some benefit from diluting ST's flaky bits by half each time.

 

There would be a small extra cost of 50p to £2.00 for the water, and it would be made easier by having a generous throughput capacity in the water system. Or an approptairelt sized pressure maintaining vessel.

 

My solar system has generated around 3500kwh since January, so that is a lot of nearly free refills, once I have swallowed the cost of the tub and the Sunamps.

 

In the absence of a Sunamp, my own domestic boiler, albeit a stonking Worcester Bosch Greenstar 42 CDi which is the top of their combi range, can deliver 17.2 l/minute at a temperature increase of 35C, which has approx 15% spare capacity over the 30C here to spend on heat losses.

 

Where am I wrong?

 

I would argue for an effective water recovery system for anyone who does this, unless you want to give greenies heart attacks.

 

And where can I get an insulated hosepipe?

 

And I suppose that this might be *one* place where heat recovery is more justifiable.

 

And who has done this? Presumably that chappie in Wales on Grand Designs with the Japanese wooden bath on his roof had something not dissimiiar in concept.

 

Ferdinand

 

Edited September 3, 2016 by Ferdinand

[Tennentslager]

21 minutes ago, Ferdinand said:

I went to a showroom in Stockport when I was looking at cars recently.

Prices went from a couple of thousand to about 15k.

 

More realistically - is it practical substantially to heat these by changing part of the water for hot water from heat stored in eg a Sunamp, or using a gas boiler - which will be about 20% of the cost of electric, rather than treating it as an expensive kettle.

 

Running some numbers.

 

According to this calculator, to heat 2000 litres of water by 15C takes 35.2 kWh.

 

A 4 cell Sunamp PV stores 10 kWh. A Sunamp stack can store up to 100kWh, though it presumably needs a stonking solar array to warm it up. But this looks like a good use for summer solar energy :-).

 

According to the brochure Sunamp output *power* for a 5kWh two-sell Sunamp PV is 35kW, which suggests that it can go from full to empty in 5/35*60 minutes. Or if we have enough heat batteries (ie seven) that there will be no issue with delivering enough heat to the hottub in 1 hour - provided we can supply enough water to carry the heat. ie the Sunamp power output is not a pinch point in the system.

 

If the water Sunamp is delivered at 50C, to match domestic hot water temperature, I make that half the water will have to be changed in the hot tub to raise the temperature from 20C to 35C.

 

Or 1 cubic metre of hot water would be required in Terry's example, which is 1000 litres. At 12l / minute volume for a normal hot tap that is 90 minutes anadi (as near as damn it).

 

Which looks to me to be a within-spitting-distance-of-being-practical way substantially to cut the cost of heating a hot tub with no loss of useability. And it would be easy to reheat when people are in it. And there would be some benefit from diluting ST's flaky bits by half each time.

 

There would be a small extra cost of 50p to £2.00 for the water, and it would be made easier by having a generous throughput capacity in the water system. Or an approptairelt sized pressure maintaining vessel.

 

My solar system has generated around 3500kwh since January, so that is a lot of nearly free refills, once I have swallowed the cost of the tub and the Sunamps.

 

In the absence of a Sunamp, my own domestic boiler, albeit a stonking Worcester Bosch Greenstar 42 CDi which is the top of their combi range, can deliver 17.2 l/minute at a temperature increase of 35C, which has approx 15% spare capacity over the 30C here to spend on heat losses.

 

Where am I wrong?

 

I would argue for an effective water recovery system for anyone who does this, unless you want to give greenies heart attacks.

 

And where can I get an insulated hosepipe?

 

And I suppose that this might be *one* place where heat recovery is more justifiable.

 

And who has done this? Presumably that chappie in Wales on Grand Designs with the Japanese wooden bath on his roof had something not dissimiiar in concept.

 

Ferdinand

 

Hi Ferdi,

Thought you were in Melbourne enjoying the southern spring?

None the less, nice to hear from you, please send some pics of the beach volleyball?

[Barney12]

I'm certain I read somewhere that a student did a PHD on pregnancy rates and hot tubs. 

From memory there was a very clear correlation showing increases in pregnancy and hot tub ownership.

flesh + heat = frisky = promiscuous = babies.

 

thus in conclusion........when it comes to self build; hot tubs and Kevin McLoud are best avoided unless you want a partner up the duff  

[Ferdinand]

2 hours ago, Tennentslager said:

Hi Ferdi,

Thought you were in Melbourne enjoying the southern spring?

None the less, nice to hear from you, please send some pics of the beach volleyball?

 

I have buffer built in.

 

Istanbul in the next day. Sydney on Tue.

[SteamyTea]

On 03/09/2016 at 20:01, Barney12 said:

I'm certain I read somewhere that a student did a PHD on pregnancy rates and hot tubs. 

There was some research done on swimming pool water quality back in the 80's, they found that most swimming pools where pregnant.

Confirmed what I always though that the words 'swimming pool' has a silent P in it.

[daiking]

Some inspiration

 

 

https://uk.pinterest.com/pin/493214596664012225/

 

lovimg the the block work one

 

Edited September 5, 2016 by daiking

[Onoff]

I find the DIY ones are never "organic" enough for me. The commercial ones are so much more sculpted!

[Bo Lee]

You might want to check out the inflatable hot tubs made by the [ company name removed ] company. They have models which have 5 inch thick foam walls, which come in 8 sections. This means that if there was an issue with one of the sections, it'd be relatively easy to deal with if you went down the "hole" route. It's pretty heat efficient, because of the foam walls, and the jets are pretty strong too.  It'll set you back about £750 but still cheaper than a rigid hot tub.

 

edited to remove reference to the supply company. Please PM Bo if you need further details. 

Edited August 28, 2017 by Nickfromwales
No direct commercial reference in new membership please