Hi Does anyone have any ideas/views on

04/29/2011 - 16:48




Does anyone have any ideas/views on what to install as back-up to a sansa heating system that currently does heating and domestic hot water (DH)…? It’s the DH we are looking at, although the stuffa is in a store room downstairs so not a heat problem for us in summer, we feel it is a waste/expense to put it on for 40-50 minutes each day for DH…. Most of the year there will only be the 2 of us living there, but come summer we will have the occasional visitors to make it 4-5 people.   Any ideas on a back-up and summer use and cost to install and run would be good… 




I'd say the cheapest installation has got to be an electric 'scaldabagno' - straightforward immersion heater. These things (Italian) tend to be a bit slow to warm up - they generally run at 1.2 to 1.5kW - but they are heavily insulated (almost like a thermos flask) so once they are hot they stay hot. If you have more than one bathroom (the second one only in use if you have visitors) then it probably makes sense to have two scaldabagni: that way you can time them (just using a plug into the socket type timer) so they are not both demanding electricity simultaneously. This gets over the potential snag of a limited kWattage on the electricity supply.  Coupling a scaldabagno into an existing boiler fed system shouldn't be too onerous - but this depends on how your current plumbing has been designed. They work most efficiently if they are close to the taps where you want the hot water, but if you can't achieve this then you'll have to put it (them) near to the boiler. They are designed to work safely at mains pressure, (so don't worry about expansion tanks, or cold water storage to give you a head pf pressure). A 120 litre scaldabagno will just about cope with a bath, and will happily cope with two showers.

... in with the sansa boiler i.e. be an alternative feed to it? No doubt you can tell, we know little about either.... :) I think we do already have a scaldabangno in the dungeon bathroom downstairs… but would not send anyone in there at present... I doubt if it's 120L,so it may not be of much use... But it is currently near the boiler (next room), so might enable the installation of a new one if they are the best way forward... Water pressure is nothing like what we are used to in Italy and quite exceptionally weak for over there.... We have been recommended to contact ACA about it, but not got around to that as yet. Ty very much Fillide for the post, that's one for the list to look at, have seen these in the shops, so will have a closer look at prices etc now... 

I totally agree with Fillide's post. Cost to buy a 120 litre scaldobagno should be in the region of €100-€125. I've even seen them discounted down to €80 from time to time. To heat from scratch, which takes 1-2 hours dependent on temperature setting will cost something in the region of €0.5. So four showers a day (emptying tank twice) and running costs to maintain temperature when no water is being drawn, you are talking at something like €1.5 per day. Mounts up over the year, but if only being switched on for a few weeks or months, could easily be your most economical solution.

Steve, Presumably the salsa furnace heats a tank already, so maybe an external immersion heater would do the trick... the cost is trivial (to install - not too bad to run just for summer either) and they work on a simple gravity circuit on your existing tank. On the same principle you can add solar power to an existing tank that was not originally designed for the job.

The payback on solar is not always as good as one might imagine so it has to be cheap to justify doing it. Here we pay €1,200 for 5mq of plain vanilla panels and then http://www.thesolarshop.eu/acatalog/Pump_Stations_from_Tiemme.html will get you a pump station and controller for £342.72 inc VAT.....fluid will be €80 odd.... all you need then is some insulated 16mm copper tube (22mm is too big and too expensive) and a trench dug in the garden (or a roof fixing kit). For buried tubes put them in those big red plastic tubes and squirt foam around them to make really sure there is no water conducting away the heat N.B. don't forget the sensor wire - 0.75mm twin flex will be fine. So the cost is under €2,000 and a bit more for help to fit it up. You don't need professional pressure filling - just pump in the fluid with a garden sprayer.. they can make 3 bar easily enough. Don't cast a concrete pad to put them on... precast kerb slabs chucked on the ground will do or we have done concrete filled plastic drain pipes too. A final word - don't chase efficiency with fancy panels... THE SUN IS FREE.