06.30.08
Euro 2008
Aw. What a shame its all over. Bill, John, Liam and Eamo. What stars. I didn’t watch the matches (except the penalty shoot-outs) but LOVED the boys. Eamo should really stick to football. He’s great. And poor Liam leaving. It was emotional really.
And good that Spain won.
NOW, I have a question.
Heating hot water in summer. Which is cheaper? The emersion or the oil-fired boiler with the radiators turned down?
FERGUS O'ROURKE said,
June 30, 2008 at 3:36 pm
Almost certainly the immersion heater but as always (nearly) ICBW. The immersion is customised to the task. Oil-burner use will inevitably result in heat loss between boiler and water-tank, as well as using energy to drive water through system.
Mol said,
June 30, 2008 at 4:24 pm
Immersion Sarah. Yours is new and well insulated so literally 15 minutes will do you to get hot water & it will stay hot.
Moll.
pete said,
June 30, 2008 at 5:50 pm
The ESB has a very good feature on their siet for calculating the cost of runnig appliances on electricity:
http://www.esb.ie/main/energy_home/appliance_calculator.jsp
They are currently charging 15c per KW-h.
According the this site, oil costs about 8.49c per KW-h:
http://www.irishlinks.co.uk/electricity-gas-oil-prices.htm
As mentioned in other comments, the immersion is much more efficient than the oil boiler, but even so I still think the oil boiler comes out slightly cheaper. There’s probably not much in it.
However, if the ESB get the price rises that they’re looking for, the oil boiler will win hands down :
http://www.independent.ie/breaking-news/national-news/esb-to-seek-30-rise-in-electricity-prices-this-year-1413595.html
Gordon Davies said,
June 30, 2008 at 6:24 pm
The idea of keeping hundreds of litres of water hot all day is somewhat ridiculous. We will be moving soon and intend installing a combinaision boiler – one that heats the water when you need it, using preheated water from a solar panel. I
For a shower unit in a guest room the logical installation is to use on of those electric shower units.
The hot water tank seems to be a legacy from Imperial times – I never saw one in nearly a quarter of a century in France.
Gordon
Sarah said,
June 30, 2008 at 6:34 pm
Oh Gordon. You can be so over the top. I heat the water before I need it. The question is how.
We did look into solar panels, wood pellets, geothermal bla bla and all that. Cost a bloody fortune and you still have to have the oil boilers for back up.
And those electrical showers use so much electricity that if you want more than one the ESB has to put special higher voltage lines into your house. When we got our electricity connected we had to tell them how many electric showers we had. One. And we’ve never used it. They are the most useless things. I’m taking it out.
Andrew Lawlor said,
June 30, 2008 at 10:27 pm
Electric showers are fantastic, Sarah. I use mine at least once a month whether I need to or not!!
Gordon Davies said,
July 2, 2008 at 9:44 am
Sarah,
Not over the top – European. I have never seen a house in Europe with a hot water tank. They do not store huge quantities of hot water they heat it when they need it. This system can be combined with solar heating in an efficient way. And you never run out of hot water. I went to a sporting event in Holland where 800 competitors got a hot shower every day.
In the same way they do not have festering tanks of cold water in the attic, water comes from the mains.
The electric showers are useful for a very specific use – when showers are required only occasionally, without much warning. An example is where I train – most people go home and change at home (the enthusiastic cycle home). The shower gets used perhaps once or twice a day – and the electric shower is the logical choice. Or, a local sailing club – showers used one day a week. It costs a fortune to heat a tank. Electric showers are logical and more eco-friendly.
Gordon
PS – Many houses do have an under-powered electircal supply, which leads to inefficiencies.
pete said,
July 2, 2008 at 10:09 am
I hadn’t heard of Gordons idea before, but it makes lots of sense. Use solar panels to keep the hot water tank warm, then boost the temperature to “hot” using an instant gas or electric heater when it’s required. Very simple and efficient.
While electric showers do use shocking amounts of electricity (no pun intended), there’s no point in taking it out. It costs nothing to leave it installed, it’s a great standby if your other water heating systems (oil/immersion) break, and it can be very handy if someone needs a shower NOW and there’s no hot water in the tank.
For a single person, it’s probably cheaper to use an electric shower than incurr the losses of storing a tank-full of hot water, but for a family a ( well-insulated) tank makes much more sense.
On a pedantic technical note, if you have more than one electric shower the ESB installs a line than can supply a higher current, not a higher voltage. Yes, I know, I’m a nerd.
Sarah said,
July 2, 2008 at 4:28 pm
I don’t get it. If you don’t have a hot water tank, then where does the water get heated?
In winter, our system is simple. We have oil fired central heating and when the radiators are hot the oil heats the water. We can switch of the oil and the hot water stays hot for hours and hours afterwards. Its not using energy to keep it warm, just to get it warm.
With the immersion we just flick it on 20 mins before we need the water (and to the “sink” option which will do two quick showers or the children’s bath. )
I don’t think that’s wasteful.
I was just wondering that if we turn on the oil, turn off the radiators, and let the water heat that way, which is more expensive? The oil or the ESB?
We did look into the solar panel thing when we built the house. What we discovered was that you had to install the whole solar thing and then the conventional heating systems too. So you need two systems – not one replacing the other. (as you point out) So the capital costs were high. We thought too high. As was the geothermal system and the wood pellet thingy.
People in Europe must heat their water some way. And there has to be some repository between a well and a tap where the water is heated.
Sarah said,
July 2, 2008 at 4:28 pm
Nerdiness forgiven btw.
pete said,
July 2, 2008 at 6:02 pm
Ok. There are basically 2 ways people get hot water to come out of their taps:
1. Stored hot water. This is what you have. Water is heated up in tank, in advance of when it is required, and stored until it is required. Of course, while stored it is losing heat to the surrounding environment (even with a very well insulated tank), and that’s what can make it wasteful. The better insulated your tank, and the less time the hot water is stored for, the less waste.
2. Instant hot water. This is how an electric shower works. Cold water from the mains is fed into the shower, and hot water comes out. Instantly. Since the hot water is not stored, no heat is lost to the surrounding environment. BUT heating water up that fast requires huge amounts of electricity, as much as running 4 tumble dryers at the same time! “Combi” gas boilers do the same thing, by using lots of gas instead of electricity.
In terms of choosing between using the oil boiler and the immersion to heat your water, as you can see from my earlier comment, oil is much cheaper in terms of raw energy (measured in kilo-watt-hours). But you have to consider how efficiently that energy gets converted into hot water.
The immersion is literally inside the tank, in contact with the water, so all of the heat from it ends up as hot water.
The oil boiler loses lots of heat through it’s chimney when it burns the oil, and more heat is lost heating up the boiler and the pipes, and keeping them hot (they will constantly lose heat to the environment). You probably lose 30% of the energy from your oil in this way (unless you have a modern “condensing” boiler and lots of insulation).
But even if you have to buy 50% more kilo-watt-hours worth of oil than electricity, to compensate for the loses, the oil still works out a bit cheaper.
Sarah said,
July 2, 2008 at 8:45 pm
hmmmmmmmm
thank you
you ARE knowledgeable.
Andrew Lawlor said,
July 2, 2008 at 10:12 pm
If all else fails, Sarah, youcould up sticks and move to Iceland.
http://www.guardian.co.uk/environment/2008/apr/22/renewableenergy.alternativeenergy
betty said,
July 3, 2008 at 12:50 pm
RE your oil system—-ours has 2 switches, one for water and one for room heating—-the water option switches on for 1 hour each am , that gives us hot water all day, though not a lot —if there is extra demand we have to boost it -the immersion or more oil. Sadly we have had to turn on the oil for heating a few evenings this year—too lazy to light the solid fuel stove.
pete said,
July 3, 2008 at 1:56 pm
Thanks Sarah, your thanks makes the 4 years that I spent in UCC getting a physics degree that never earned me a penny all worthwhile
Liam said,
July 3, 2008 at 2:15 pm
Would Solar panels look after all your hot water needs from April to October?
The remaining months would be covered by your space heating system, your oil boiler, and by using the two you would have constant hot water, yes? Or is this wishful thinking on my part?
betty said,
July 3, 2008 at 2:38 pm
Liam, I believe on a cost benefit analysis it takes 14 years to recover the cost of installing solar panels , 8 years to recover the cost of wood pellet stoves (complicated by supply of said pellets) and 18-20 years for geothermal systems(plus high running costs). Use less hot water, turn down the thermostat, wear a cardi,etc, or have a solid fuel in the main living area, downside —dusty ,work , ashes, but felxibility of supply—grow your own, Sarah.