Andy Hall of Fame

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This is a continuation to the tribute page for Andy Hall, one of the most prolific posters ever to uk.d-i-y

If you have interesting links, to notable Andy threads, then please post them here.


Where do we start... how about these

Running Heating service to outbuildings

On Fri, 21 Nov 2003 11:26:21 -0000, "Paul"> wrote:

do you think it would be ok to go with my suggestion if i omit the gas and
replace it with a central heating flow and return in plastic along with a
domestic HW feed, all from the house combi boiler?

thanks again

I've done something along these lines between the house and my garage workshop.

The first point, though is that the power cable (which should be armoured SWA) should be kept quite separate from any piped services and not run in the same duct. It can in any case be run or buried in the ground.

I did not run a water service, but did run a heating service using 22mm plastic barrier pipe. This was implemented by insulating each pipe with very thick Armourflex insulation (IIRC I used the 22mm thick stuff). The pipes were then threaded through 150mm soil pipe from end to end with the pipe buried, of course. If they were run above ground in some form of box then I would suggest more insulation packed around them.

As far as hot water is concerned, unless you want a lot of it, it may be more practical to run a cold service and have a small electric heater for it in the garage.

One thing that I did do for the heating was to arrange a completely separate circuit rather than running the main heating circuit to the workshop. I did this by using a stainless steel plate heat exchanger to separate the circuits and transfer the heat. The primary side of it is connected to the house CH flow and return with a two port zone valve to control when heat goes to the heat exchanger. The secondary side connects to the workshop circuit which is run sealed. There is a filling loop at a convenient point in the house but the pressure vessel is in the garage where there is a convenient location for it. In the garage there is a separate pump and of course the pipework to the radiators.

The secondary system is controlled by a timer/thermostat which operates the pump. On the secondary circuit in the house there is a flow switch which operates the zone valve. Thus, when there is a demand for heat in the workshop, the pump runs, the flow switch detects it and closes and the zone valve opens and signals the boiler that heat is required.

The reason for the extra complexity is because I did not want to risk compromising the house CH system if anything went wrong with the workshop circuit - for example damage to the pipe etc. I also added a combined corrosion inhibitor and antifreeze (Fernox Alphi-11) to the workshop circuit at a concentration sufficient for -15 degree temperatures. This stuff is relatively expensive, but it would be foolhardy not to use it because if the workshop pump fails or the heating is off for a period, there would be a risk of freezing, insulation or not. It was another reason to separate the systems so that the whole system including the inside would not need to be dosed. The workshop part of my system needed 4 containers of this stuff at around £15 a go and if the house system had been combined another 4-5, so this went most of the way to the heat exchanger cost.

Because of the added volume of water, an additional pressure vessel would have been required for a combined system, so separating the systems did not add to this cost.

Overall, the arrangement works extremely well. I insulated the workshop very thoroughly with Celotex, which reduces the heat loss to 3-4kW, and I sized the radiators to provide quite a bit more than that.

Ding Dongs

Andy had some famous running discussions - many with IMM (aka Adam, Doctor Drivel etc). Here is one