Not Stag Related-----------------Heat Pumps

[RogerP]

Hi
Hopefully someone can help shed some light as we've such a diverse group on here.....I'm looking at reducing our gas bill, now our boiler is some 30 years old and it's either on or off, although we've thermostactic valves on all radiators we have to have the boiler on to heat the water.....I have just tried using the emersion heater using the energy produced form the Solar Panels and that works fine...So i'm now thinking of a heatpump for background heat because I can also run that from the Panels during the day........................Question is has anybody got any experiance of these heatpumps or come to that anything else, are they anygood??

RogerP

[liam]

Hi Roger I have been involved in quite a few heat pump installations They are good when fitted correctly ,the heat pumps run at lower temperatures so are ideally suited to under floor heating which generally runs at lower temperatures than radiators, you can run a heat pump on rads but you will more than likely have to up size your rads to compensate so as to reach the same heat outputs as your boiler system, another consideration you need to make will be that you may have to fit whats called a buffer tank which can be as big as a normal cylinder as well as a cylinder to store the hot water..
I have been impressed with the ones that I've been involved with & would recommend them in a new install as mentioned before,fairly sure there are grants available for these but to get these you have to use an accredited installer.
I have a wood pellet boiler which is doing our hot water & underfloor heating & also hot water solar panels for hot water which for the last 3 weeks has pretty much done all our hot water I would say that the pellet boiler is ok but time over again the heat pump would have been the way to go less dust & mess, I have to store 3 tonnes of pellets at a time as we live in west Cornwall there isn't a local supplier so we buy all the fuel in one go & you have to manualy fill the boiler & clean it once a week which whilst not difficult is a bit of a drag, one other thing we have got is a wood burner which keeps fuel bills down as my brother is a tree surgeon & I tend to bring timber home from work on building sites . Hope this gives you a little more idea give me a call if you want.
Liam

[Guest]

Liam is there the capabioity to run those bio-mass boilers from mains services if needed?

[RogerP]

Hi Liam

Thanks for the detailed reply, the one's I was looking at are the Air Conditioning type, so you can have hot and cold.

Roger

[liam]

Piscean not quite sure what you mean?
Liam

[liam]

Hi Liam

Thanks for the detailed reply, the one's I was looking at are the Air Conditioning type, so you can have hot and cold.

Roger

Hi Roger
Each manufacturer has different features Never seen one set up to do that so can not state for sure, I know you can do this with air con but not sure about air source heat pumps .
Just for your information there are air source ,ground source which can be layed with coils of pipe about 1 mtr below ground in trenches ,you can also use a bore hole as well & the last one which is possibly the least known about is the water to heat heat pump where a pipe is placed in a lake or even the sea ,my experience has been with air source & the bore hole method, air source is probably most popular as there are no additional cost other than buying the kit & know are all most as efficient as other systems generally around a 3 to 1 efficiency to give you a better idea the last one I was involved with on normal running the current being drawn was around 9 amps around 2 killowatts this was in a refurbed large 3/4 bed house well insulated all under floor heated & all hot water, guessing electricity is around the 15ppkwh mark there is a potential of max running @ 30pphr but realistically these would be top end figure on a new install running cost.he key to any insatall is to ensure you have as much insulation installed as possible.
if you wish to pm me i would be more than happy to talk to you.
liam

[Guest]

Piscean not quite sure what you mean?
Liam

Hello Liam,

Sorry for being uncloear. The pellet burning boilers are called bi-mass boiler I think. Do you know if they can also run on mains gas / electric?

Ian

[Jeff]

Hi Liam

Thanks for the detailed reply, the one's I was looking at are the Air Conditioning type, so you can have hot and cold.
L
Roger

Hi Roger,

I have a Panasonic a/c unit in our conservatory giving cold air in summer but we use this more in the winter as a heater, only drawback is if it's too cold outside, it does affect the heat output. We are in Spain at the moment and have an LG unit much the same as the Panasonic and that unit heated the whole place in December, don't need it on at the moment.

There is a lot of talk about the air source heat pump which I believe is cheaper to run but do not know too much about them.

Jeff.

[Westfaling]

Guys
Before deciding on heat pumps or other heat sources you really need to establish the cost of heat (per kWh or whatever) for each heat source to see if it's really going to save you money. Air source heat pumps will usually give a seasonal coefficient of performance around 3.0 on average so you can divide your average electrical cost by 3 to establish the cost per kWh. There should be plenty of on-line calculators for this. When burning gas, oil, coal etc you need to take account the (seasonal) efficiency of the appliance to figure out the real cost of heat. This could be as low as 60% or as high as 95%+ for condensing gas boilers. I'm not up to date with energy costs in the UK so I can't give specific advice but you should note that air source heat pumps may only last 10-15 years. I'm not against them I heat my house with a ducted air source heat pump but you need to do the arithmetic before deciding.
Nick

[liam]

Hi piscean57
You can install any type of heat source to work with any other type if installed corectly I am not aware of any one making a dual fuel type unit perhaps you are on to some thing there,see you on dragons den soon ,Joking apart the bio mass unit we have can also burn logs as well as pellets.
liam

[73stagman]

My landlord (and next door neighbour) uses ground source heat pump and solar panels and reckons its all good value but read here and the savings versus cost of installation are not great.
http://www.energysavingtrust.org.uk/Generate-your-own-energy/Ground-source-heat-pumps

[marshman]

Hi Roger,

Personally I would forget it - its a non starter as far as getting your PV to power any form of heating. When you actually want it to provide heat - in the winter months - the solar panels are producing least amount of electricity. I assume you have 3 to 4kW pk of panels - they only produce full output for a few hours around mid day in the summer months. I suspect you could use most of the power they generate to heat your water, do the washing etc. A better way to heat your water would be directly via thermal solar panels. As already suggested you could use PV to power airconditioning (cooling) as peak production from the PV matches peak demand for cooling. My experience of hot air for heating at home is that it can be inefficient as it causes drafts and its not a pleasant heat. It can also be noisy. I would get the boiler replaced with a modern condensing boiler.

The main problem with PV and large loads is matching the generated power to your demand. If you go and boil a kettle whilst having your air source heat pump running you will almost certainly end up paying for some "imported" power at peak rate. To be honest I think people over estimate how much useable power PV produces. At best you will get 1000 units per 1kW pk installed per year - so for a 4kW system (in the south of the country) you will get around 4000 units which equates to about £800 worth at peak rates (depending on your tariff) - You can easily use around 50% anyway just in normal day to day consumption - so the maximum left is £400 worth. Also bear in mind that a lot of the time you will only be generating 1 or 2 kW - in the early morning and late afternoon, or if its a bit cloudy. So that is not going to provide enough to run a large load without being supplemented from the grid at peak rates. I suspect this already happens more often than you realise at the moment when you have your immersion heater on.

I have 2 PV systems of my own, one of which I monitor by datalogging its output every 30 seconds throughout the day (I have several large anoraks and I'm not afraid to wear them). If I look through the log files its amazing how the output fluctuates over even short periods on apparently bright sunny days.

Just my 2p worth.

Roger