Saving on heating bills

[Pauline]

Yes, I agree that gas is undoubtedly still cheaper than electricity at present, and that may always be the case - I don’t know.

In our previous house we had a hot water cylinder rather than a combi system, and that had an immersion heater for use in the summer when the central heating was off. However, we found it was much cheaper to continue using the gas boiler to heat the water over the summer.

 

[Bryman]

I wasn't aware of a heat pump that will heat water being available in NZ We have two heat pumps, one at each end of the house, they hang on the wall just below ceiling height and heat or cool the air in the room depending on how they are set.

I think that all domestic heat pumps heat/cool water which is then pumped into the home where the heat exchanger (wall or floor mounted) blows air over the pipes/vanes to achieve the desired effect. The photo shown is that of the heat exchanger. The heat pump itself is located outside and is similar to a kitchen refrigerator running normally to cool and in reverse to heat.

In my case I do not have a heat exchanger unit. The water pipes are buried in the concrete floor which operates effectively as a large night storage radiator and there are no units either wall or floor mounted. This also means that I do not get any cooling effect during the summer, which I am happy with as that avoids a lot of extra operating cost.

 

[Heather]

That's what we'd call an air-conditioning unit in Europe.

In Australia, if it just cools it is an air conditioner, if it both cools and heats it is called a split system or reverse cycle air conditioner.

 

[At home in NZ]

It seems we are all talking at cross purposes because we use different methods of heating our homes in different countries and call things by different names.

The heat pump in NZ is for heating the home when warmth is required and as an air conditioner when it's too hot in summer.
From the beginner's guide to Heat Pumps:
"A heat pump is like a reverse refrigerator.
Two coils, one inside your home and one outside, draw warmth from the outside air and transfer it into your house. Because a heat pump doesn’t require heating elements it is energy efficient to run.
It can also be used to cool your house during the summer."

This has reminded me about how my partner and I were talking about having to learn new words and ways of doing things when we arrived in NZ.
One outstanding example is 'bring a plate'.

 

[Pauline]

In Australia, if it just cools it is an air conditioner, if it both cools and heats it is called a split system or reverse cycle air conditioner.

The latter are used mostly in commercial premises in the UK, I think. The shop beneath us has one, which heats or cools as necessary, but they also have a central heating boiler. The unit outside is about a metre square and sticks out from the wall about half a metre, with space behind it, and has one fan - some of the units I've seen for use as domestic heat pumps have two, but maybe they are for larger houses.

The air conditioning unit is pretty noisy, though, and we can hear it throughout our flat. It's only used when the shop is open and would make sleep impossible if it was running overnight, particularly as it sited on the wall below the bedroom, though I don't think it is any noisier than other air conditioning units I've heard.

I hope the external units for domestic heat pumps will be considerably quieter, for while you could opt to keep your own turned off overnight, you can't control what your neighbours do.

 

[peter]

The latter are used mostly in commercial premises in the UK, I think.

Perhaps I move in the wrong circles, but I don't know anyone in the UK who has either type in their home - it's pretty rare that the temperature gets uncomfortably hot, which is one reason why so many Britons go abroad on holiday (when they're allowed to), and why for many years many of us thought global warming was 'a good thing'. But you'll find both types in holiday apartments in southern Europe.

The air conditioning unit is pretty noisy, though, and we can hear it throughout our flat.

That's possibly because you have your windows open and/or they're not double-glazed. Air-conditioners in shops have to work doubly hard because of the opening and closing of the door as customers leave and enter - ideally when you use air-conditioning all the doors and windows need to be closed, which is why in many hotels the air-conditioning switches off automatically if you open the window.

 

[Pauline]

That's possibly because you have your windows open and/or they're not double-glazed.

All our windows are double-glazed, and the unit is noisy inside even when all the windows are shut.

 

[peter]

All our windows are double-glazed, and the unit is noisy inside even when all the windows are shut.

In that case it's either vibration transmitted through the brickwork, which could be resolved by modifying the mountings, or sound from the internal fittings coming through the floor. Double-glazed windows are supposedly capable of reducing noise by up to 31dB according to one supplier, while another suggests that secondary double glazing can reduce noise by 50dB (but then says that is a 50% reduction in noise, which is actually 3dB - so I'm not sure they know what they're talking about!). What I do know is that we live next to the motorway and close to an airport, and even single-glazing makes an enormous difference to the noise level.

 

[Pauline]

In that case it's either vibration transmitted through the brickwork, which could be resolved by modifying the mountings, or sound from the internal fittings coming through the floor.

Since the unit doesn't run overnight, nor that often during the day, we haven't investigated that closely. We can hear some noise coming through the ceiling, but only if you lie down and put your ear to the floor - something I don't tend do that often! And I guess there may be some vibrations in the wall, but mostly I think we can just hear it, as it's loudest if we stand by the windows on that side. You can hear it outside when it's running, and most nearby outside noises can be heard inside albeit more quietly when the windows are shut.

 

[Pauline]

Perhaps I move in the wrong circles, but I don't know anyone in the UK who has either type in their home - it's pretty rare that the temperature gets uncomfortably hot

I don’t know anyone personally, but I have heard of people having them, and once when we were looking at houses for sale we came across one with an air-conditioner. I’ve no idea which type, though, and we didn’t view that house.

 

[Bob Spiers]

It's a good practical option, but unworkable financially - nobody is going to change from a gas boiler if it means their annual bills will be 3 times higher.

Only recently picked up these postings again, and the above Statement rang so true I simply have to have my say. We bought a new Gas Boiler in May which was installed and up and running in June. I took a long time considering options and chose a Worcester Bosch wall hung condensing boiler bought from and installed by British Gas. Compared to the old one, super quiet and it is monitored 24/7 by a Boiler IQ, part of my Hive system. This is the 3rd boiler in the house: both previous being Pottertons, one that came with the house when we moved in in 1986; the second bought early 2000's and gave stout service up until this year. It had become noisy and the maintenance contract (Homecare) reflected cost-wise the fact parts were getting hard to locate. A new boiler had to be considered and was.

Our Homecare monthly contract has halved, and as I have been monitoring the daily Electricity/Gas costs via our Smart Meter and via our suppliers excellent monitoring reports (We are with OVO on a dual fuel contract, and have agreed to a £5 GREEN supplement per month). But it is responding to Electricity versus Gas costs that I wish now to comment.

We are not the most cost effective couple in the way we use Electricity (by that I mean mostly me with my computer devices, use of lights and appliances on standby 24/7 ) but no sermons please. Whereas my wife likely causes a high gas usage requiring higher thermostat/or time Schedule settings, plus my cooking demands of a Gas Hob and Electric Oven But all that aside, even over the summer months the Monthly average cost between Electric usage and Gas was near as makes little difference 3 to 1.

I monitor costs on a spreadsheet, updated monthly and will be doing so throughout the winter. I can say however that were it not for Gas for central heating and cooking and we had to rely on Electricity for both - then our energy costs would be through the roof, however well insulated it may be.

 

[Bryman]

I can say however that were it not for Gas for central heating and cooking and we had to rely on Electricity for both - then our energy costs would be through the roof, however well insulated it may be.

I think that the only way that electricity can be competitive is by using it with the cheap overnight rate which is probably about 1/3 of daytime rate. I took advantage of building a new house to get underfloor heating installed but that is not generally feasible to retro-fit for existing houses. Night storage heaters would be one avenue to investigate but they are not as flexible or responsive in their use as gas.

However, it should be possible to well insulate such heat storage devices to avoid overheating rooms if weather turns mild and to incorporate a fan to boost heat output if the next day turns out to be extra cold.

 

[peter]

I took advantage of building a new house to get underfloor heating installed but that is not generally feasible to retro-fit for existing houses

Presumably it only works for single-storey homes - what we would call bungalows.

 

[Bryman]

Presumably it only works for single-storey homes - what we would call bungalows.

It could also work for multi-storey homes as long as the heat storage medium can be supported at higher levels. In my case the concrete slab was something like 4-6" thick, or so, and would be heavy to support above ground level. However, that is not an unusual amount of concrete in high rise office blocks so not impossible. I have not investigated alternative media for heat stores so that might lead to something easier to incorporate, although possibly more expensive.

I have just read the one page article in the latest New Scientist (issue 23/Oct) which suggests that heat pumps would be more expensive in UK than many other countries. Is that because only British designed and built models are to be installed? NZ relies on mainly Japanese and European manufacturers which may be further into development and hence able to supply at lower cost?

Sorry to be running out of time again but have just been watching the penultimate episode of "Vigil" and now time to go to sleep.

 

[peter]

I have just read the one page article in the latest New Scientist (issue 23/Oct) which suggests that heat pumps would be more expensive in UK than many other countries. Is that because only British designed and built models are to be installed? NZ relies on mainly Japanese and European manufacturers which may be further into development and hence able to supply at lower cost?

I couldn't see anything in the article that suggested heat pumps would be more expensive than in other countries, nor would I expect this to be the case. Note that the price they mention includes installation, which could well be the majority of the cost for a homeowner switching from a gas-fired boiler - when we replaced our old oil boiler with a new and much more efficient one the cost of the boiler itself was about one-third of the total bill.

 

[Bob Spiers]

Night storage heaters would be one avenue to investigate but they are not as flexible or responsive in their use as gas.

Have never had, nor would I ever want Electric Night storage heaters. My UK sister inherited them back in the 70's/early 80's and never stopped complaining that the house was occasionally too warm (first thing in the morning) but barely comfortable for the rest of the day, and in many cases giving out no heat. She had just gone through a sticky divorce which she won and the house was part of the settlement as was custody of her 4 children. She needed a warm house especially during the winter. From mid/late morning onward the heaters were more ornament than use. She would often ask me if I knew how they could be better regulated, but I had no knowledge of their working. I arranged for a local heating contractor to visit, but the end result was always that the heaters (possibly past their prime) were set to perform to come on at night and retain a residual heat during the day. Just that the residual heat was totally ineffective and she had no money to do anything about it.

She endured the house for a couple of years and then found a new partner and eventually they married and rented a house that had gas central heating. She vowed never again to return to a house warmed by night storage heating even if on Economy 7 Tariffs. I have always considered Economy 7 to be false economy where night storage heating is concerned, and have never bothered to explore any of its other so called 'cost saving' benefits like running washing machines at night, and such.

 

[peter]

Have never had, nor would I ever want Electric Night storage heaters.

Me neither - my in-laws had them and it was always too hot or too cold (mostly the former, which meant that energy was wasted when the patio doors were left open).

 

[Pauline]

Me neither - my in-laws had them and it was always too hot or too cold (mostly the former, which meant that energy was wasted when the patio doors were left open).

My in-laws also had them, and there it was mostly the latter - too cold. And I say that despite us not having any central heating at all in our own home at the time.

 

[jorghes]

Presumably it only works for single-storey homes - what we would call bungalows.

Ah, bungalow... such a confusing word for an Australian. (we simply call UK bungalows - "houses")

 

[peter]

Ah, bungalow... such a confusing word for an Australian. (we simply call UK bungalows - "houses")

On the contrary - I deliberately chose the word bungalow because is not capable of misinterpretation.