BBB 2015 hot tub

[Jamesrl]

I've just run up the pump and checked fittings with hose and copper coil, it all plumbs together a treat

You're gonna need some serious coil and heat input to exceed  heat loss to the ground and atmosphere.

[Tony]

Maybe someone else with another M67?

They're about 65000 BTUs, though can peak at more than double that at the expense of chuffing and soot.

[Head Womble]

I was thinking about this today, we need to get the ball rolling as there's not much time left.

Can the M67 be cleaned so no heat exchanger is needed, would solve a lot of problems.
To maintain level in the M67 drum you just pump water into the drum and run the outlet as an overflow.

[Tony]

What do you mean by outlet? It would overflow, for sure   I considered adding a port to the side but then you need decent plastic waste plumbing for the return, and a suitable height differential - it would mean an elevated platform for the M67 and drum, which doesn't sound too safe.

[Dickjotec]

I heat my tub from a 205L tank, heated by either the Lister or a boiler, using a finned heat exchanger from a CH boiler. The HE is under a wooden duck board, held down with some slab cut to shape. This has worked well for a number of years. It raises the temp by about 1 degree an hour. the heat source has to run for less than an hour a day. Pumps etc are controlled from PIDs. Initial heat of the year is boosted with a heater from one of the inflatable tubs I got second hand run from the lister, this gets it up to temp in a day. We run at 37c with the 205 never over 60c, a bigger differential would, of course heat it quicker.
If you go for a tank I would suggest placing your tub on some polystyrene and lagging with bales.

[Tony]

Well the copper coil I have is 12mm, I'm not sure how long (I'll have to check, either 5m or 10m) so should heat water nicely enough, the question is flow rate through it and the garden hose (and loss to atmosphere from the hose).  The 205 I'm sure we can get up to 60-80C though with kids around it's probably better to keep it on the lower end, certainly when we start we can bump the temp right up to get things going.

[Dickjotec]

My tub, and the house and cabin, is fed through 15mm barrier pipe admittedly underground, and there is very little loss. Circulation with a CH pump and a big height difference.

[Tony]

Just checked and the coil I've got is 10m, it's only the flow that is a worry.  Perhaps we need pipe insulation for the hose?

[Dickjotec]

Depends on how far the 205 is from the tub. I would not worry if it is up to 15M. The water is not in the pipe long enough to loose much heat to air. I assume a cCH pump is planned for the circulation?

[Tony]

This fits hose pipe perfectly

http://m.rs-online.com/h5/mobile/uk/catalog?url=%2Fweb%2Fp%2Fcentrifugal-pumps%2F0266979%2F

(I didn't pay that for it!)

[Keef]

Love it ...... Tony, the man with a pump for every occasion 

[Tony]

It's a pleasure, and a curse

[knighty]

everything's gone to crap here

went to make some phone calls and left a lad moving some stuff around to get the tank out and tidy up a bit in the process... he knocked the forklift into gear as he jumped off it (without putting the hand break on)

forklift drove off and straight into the tank, crushing it against a wall

totally ruined :-(



anyone have any other ideas of a tank ?  I'll collect and bring it down to the BBB no problem

feel really crap after everyone's made plans around this tank :-(

[Tony]

Depends on how far the 205 is from the tub. I would not worry if it is up to 15M.

Can't have it too close or the tub will get a layer of soot on it from the M67 if the wind is the wrong way (particularly when it's running full chatter).  I wonder if the wind blows a particular way on average there?

totally ruined :-(

That's a shame but at least no-one got hurt in the incident, could have been a lot lot worse.  We'll just have to find another way.

[Dickjotec]

How about
Cut an IBC down. Cut it into quarters then extend the sides with shuttering or OSB. Line with polythene or buttyl if anyone has some. Might need a frame round the top but should work unless huge.