Very unusual "Central Heating System"

[buffster]

I've described this as a central heating system, purely because the fundamental part of it is an ordinary radiator, but that's about the only thing that's ordinary about it. What I'm looking at doing is having a single radiator (say 1m by 1m), a small tank with an electric element heating it, and a pump. There will be very little pipework (ie the tank will be very close to the radiator).

So, will something as basic as this actually work? Also, will an ordinary radiator work if it's nearly horizontal - especially with regards to airlocks/bleeding? I know all this sounds bizarre, and it's obviously not for heating a house or anything like that, but it could provide a solution to an interesting problem. The power will almost certainly have to be electric, but the radiator itself will be in a potentially wet environment, which is why I'm considering a solution along these lines rather than a simple oil filled radiator.

Have tried to add a basic drawing. View media item 48229

 

[Norcon]

but the radiator itself will be in a potentially wet environment

The radiator will rust and corrode for a past time and won't last that long.

 

[buffster]

but the radiator itself will be in a potentially wet environment

The radiator will rust and corrode for a past time and won't last that long.

Thanks for your response.

It's a short term project, only about 2 months, so I'm not concerned about corrosion in such a short space of time.

 

[mickyg]

it wont heat up evenly if its horizontal, maybe if you pipe it tboe it will be ok ish...but design of radiators rely on some gravity. It seems like a crazy ar5ed plan tbh... Why do you need the tank?? Why not stick and electrical element in the rad

 

[roguetrader]

We use a small direct unvented cylinder in a similar way when we want to get underfloor heating up and running on any refurb work. We rig up 2 immersions and set the stats accordingly.

 

[buffster]

it wont heat up evenly if its horizontal, maybe if you pipe it tboe it will be ok ish...but design of radiators rely on some gravity. It seems like a crazy ar5ed plan tbh... Why do you need the tank?? Why not stick and electrical element in the rad

It is kinda a crazy plan as you say, but I'm just running a few things through my head and this ticks a lot of boxes so I wanted to see if it was viable. The issue with an element in the radiator itself is that I thought the wet environment that the radiator will be in would make this unworkable. I wanted the electrical stuff isolated from the radiator itself.

We use a small direct unvented cylinder in a similar way when we want to get underfloor heating up and running on any refurb work. We rig up 2 immersions and set the stats accordingly.

So in theory it would work without an expansion tank to pressurise it?

As there is very little pipework and just one radiator, would a suitable pump be enough to ensure that water kept circulating through the system, heating the radiator as it does so?

I guess the radiator could be at a 30 degree angle to the horizontal if that would help it work, would that be sufficient to make it work properly?

 

[Onetap]

The radiator won't heat uniformly, they need to be upright.

Use electric heater tapes embedded in a sand/cement screed, as used in UFH, and cut out the water. The heater tapes/cables are used in bathrooms, so the wet environment shouldn't be a problem. Or use heater mats, as used for home brewing.

If you really want the water, use a grid of pipes in screed, with an air-vent. Use a F&E tank on the cylinder; most domestic cylinders have the immersion heater at the top, so the cylinder needs to be filled to the top.

 

[SimonH2]

I can't see why it won't work. With just one rad and a standard pump, you'll be able to get flow rates that will most likely kill any cold spots.

You may have to experiment with connections a bit. Using diagonal connections would ensure that the water has to flow through the panel, but inertia may make it want to 'squirt' along the heater on the inlet side and only pass through the panel at the far end. Worst case is that you may need a 'spray bar' in one side*. In reality though, I can't see that sort of flow rate, with only 1kW/m^2 allowing much by way of dead spots. It's not going to cost a lot to try.

The water container doesn't need to be pressurised as long as the surface is always above all the plumbing. Keep the pump in the flow side as shown, but take the return direct into the tank rather going over the top.

Don't worry about bleeding. Any air will be carried round and settle out in the tank - as long as you don't have things too turbulent.

* Simply a length of pipe through which the inlet water has to flow. The end is capped, so the only way out is via a number of holes drilled in it - thus ensuring a distribution of flow. That's how the candle moulds at my last place work.
To make one, I can think (offhand) of two ways.
1) Drill out if necessary the rad side of the inlet fitting so you can solder a length of copper pipe into it. BTW - you won't be needing valves, just use BSP-compression fittings. The pipe needs to be a little shorter than the rad, and the end needs to be capped. Drill a series of holes in the pipe. Then feed it in and screw it home.
1b) just turn/file out the stop inside the fitting until a length of pipe will go all the way through - fixed by the compression coupling, and leaving you with a 15mm tail to connect to.
2) Use a standard 15-10mm reducer, and carefully file out the ridge that forms a stop for the 10mm pipe. Pass through a bit of 10mm pipe that's longer than the rad and solder it in place. The 15mm section goes into the rad fitting (with a bit of 15mm pipe if it's a female-female reducer), leaving you with a 10mm tail to connect to.

EDIT: Doh, dunno where the 1kW came into my head from

To add, since there's no need for all the usual controlled flow rates etc, "normal" rules for a rad don't really apply.

 

[SimonH2]

Oops, double post

 

[dcawkwell]

Can't see why you wouldn't use a normal oil filled radiator.
It will do the same.

 

[Whitespirit66]

Two things;

1) You are going to have to keep topping the tank up, as not being sealed, you will loose water due to evaporation. It will eventually boil dry.

2) The draw off and return pipes are very close together in the tank. They will short circuit, meaning as soon as the cooler water comes out of the end of the blue return pipe, it will be drawn back into the flow pipe outlet. Ideally, the flow should be drawn from the hotter water at the top of the tank, not the bottom. However, due to evaporation and the consequent dropping of the water level, this may not be practical.

 

[OLLIE20]

If i was a copper If it wasn't 2 months , with the things you're saying very small room, hot water, moist environment, not to bothered about it not working after, I'd probably be after raiding this gaf, if you know what I mean

 

[gavinda]

This is the second time I've read this thread, the first time I thought he OP was a nutter.

Then I thought the above

 

[SimonH2]

The same thought had passed my mind - any medicinal herbs involved ? But then, don't they usually use overhead lamps for that ?
EDIT: Quickly adding, from what I've seen on TV !

 

[Whitespirit66]

I wouldn't have a clue what you are 'reefering' to!