Nibe Fighter 360p ashp costing me loads to run

ra200

You can heat the house using the exhaust air providing the outdoor temp is above 8c but below that you need the system in winter mode so the system is allowed to use the 7kw immersion to boost the water / flow temp but the more the outdoor temp drops below 8c the more the system uses the immersion resulting in very high electricity use below 2c outside the system is almost relying on the immersion for the heat make is very uneconomical ,

The fresh air is provided in vents in the windows and the system has three exhaust ducts one in the kitchen one in the shower room and one in the bathroom, the only problem with the vents in the windows is when it is cold out it makes the room colder a very stupid design I think,

John_Pierpoint wrote: »

How much "fresh" air does this Nibe 360P use, in addition to the waste energy it is seeking in the exhaust air from the house?

There is no way that a house can be re heated efficiently by putting back the heat that is mechanically removed in the exhaust gas and speeding up the process as the weather gets colder.
http://www.bbc.co.uk/dna/h2g2/A467714
In such a system the only new heat added to the loop would be full price electricity used coincidently in the house plus about 80 - 120 watts for each sweaty occupant. (let us pretend that no gas is available in the property).
It makes a little sense as a dehumidifier for a house that is hermetically sealed to "passiv hause" standards:
http://www.renewables-in-school.eu/WorksPassivHouse.htm

Meanwhile I think the original poster will be interested in this thread:
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6681

grahamc2003

John_Pierpoint wrote: »

How much "fresh" air does this Nibe 360P use, in addition to the waste energy it is seeking in the exhaust air from the house?

There is no way that a house can be re heated efficiently by putting back the heat that is mechanically removed in the exhaust gas and speeding up the process as the weather gets colder.
http://www.bbc.co.uk/dna/h2g2/A467714
In such a system the only new heat added to the loop would be full price electricity used coincidently in the house plus about 80 - 120 watts for each sweaty occupant. (let us pretend that no gas is available in the property).
It makes a little sense as a dehumidifier for a house that is hermetically sealed to "passiv hause" standards:
http://www.renewables-in-school.eu/WorksPassivHouse.htm

Meanwhile I think the original poster will be interested in this thread:
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6681

It takes a bit of getting your head around, but I think a house could be heated efficiently by using such an exhaust system. I must admit, I initially thought as you John, that it seems to be a circular nonsense to extract the heat from air going out the house to heat the air going in.

However, these systems are installed in other places and they work well apparently (I accept there are many problems with them for posters on here), so good evidence it's time to think a little further how the thermodynamics may work.

The key is that the warm air leaving the house and warming the working fluid is cooled to a much lower temperature than ambient. E,g, if its 7c ambient, and the exhaust air is at 20C, the air exiting the heat exchanger (having heated the working fluid) is probably far below 7C and possibly something like -10 or -20C. From that likely scenario, you can see the attraction of such an exhaust system - the cop could be very high indeed, negated to some extent by the exhausting of warm air from the house. It even explains why they have masisve electric heaters built in - simply to get to a steady state of 20c (eg) inside the house, which could be difficult to acheive from the heat pump alone at low temperatures. At steady state, the heat supplied by the heat pump would have to be the heat loss from the house structure (the normal situation) plus the heat loss from the exhaust air (a difference from a conventional system). I can see that its certainly probable that the very high cop (due to warm air used toi heat the refridgerant) could more than compensate for the extra heat load exhausting the warm air entails. (I've done a lot of thermodynamics, and it takes quite a bit for me to get my head around this system, but now it seems a pretty good system to me, at least in theory).

So there's no doubt that there's nothing in the thermodynamics saying such a system coiuldn't work, and indeed, it looks like there are some positive features of such a system (when working coirrectly).

No help for those having problems with their systems of course. I'd say the problem, assuming everything is set up correctly, that the house doesn't reach the required steady state temp, even with 8kw heaters going, for the system to get into its efficient range. That could be down to extremely poor insulation or the heat escaping through draughts and not making it to the system exhaust point (or many other reasons I suspect).

John_Pierpoint

Yes I get your point and I had missed the fact that the exhaust air might be considerably below the external ambient temperature.

However if the exhaust is approaching zero the sweaty internal air is useful input to an ice maker - and then the ice and its latent heat has to be melted to get rid of it.

Modern building designs are all about reducing the rate of air change - the mantra is "build tight - ventilate right". It seems to me we have a building where draughts are being dragged in through the various vapour barriers in the depth of winter and being put through a heat pump to produce a large rise in temperature and so an inefficient level of COP.
I have heard people in this new industry talking about "flat building syndrome" where the temperature inside and out of the building is so cold that the heat pump seems to make no progress in heating up the building (more in the context of rich people getting back from a skiing holiday and trying to turn on their heating). It does not really make sense to me but I will agree that my solid fuel heating would take a day and a half to get my home back to 20 degrees, if I were to leave it for a fortnight and come back to internal temperatures of say 10 degrees (I have good thermal gain through the windows as the property is well oriented and reasonably well insulated).

At least give the poor tenant a log burner, so he has the same control over his financial destiny in mid winter, as a gypsy in a caravan. (*)
Most of these eco warriors tend to love their a log burner:

http://www.sustainable-energyacademy.org.uk/superhomes

(*) Woops that would not work as the "active" heat recovery and augmentation pump would gas the occupants by sucking the log burning gasses back down the flue and into the room, I have a feeling that sucking the other way would not work with wood but it would work with the flue gasses from a gas boiler (hopefully CO2 and water with just a trace of NOx and SO2?) !!

ra200

Our house that is build to code level 3 has double glassing windows and 100m insulation board in the walls and around 200mm loft insulation but the build quality of our house is very poor the flooring is coming up and the plastering is poor I think the carpenter who made the doorframes and hanged the doors was blind that’s how bad the workmanship of Greenhill is the only good reports I have heard about the Nibe 360p if from people who have them in higher insulated houses that are of good build quality and they have a second source of heat like as a log burner so the Nibe 360p is a good bit of kit if installed in the right environment so Nibe can thank the house builder for their product getting a bad name,

I have left the Nibe 360p on since yesterday to test it and it is 8.9c outside and the nibe is struggling to heat the house in autumn/spring mode (immersion disabled) just using the compress at this moment 1.45pm it is try to achieve a flow rate temp of 36c but can only get it to 34c and the hot water is 33c for me to have hot water of 55c and the flow rate temp of 36c the nibe would have to be put in to winter mode to allow the immersion to kick in, So for me to have a warm house tonight I would have to put it in winter mode by 3pm to allow the under floor heating to heat up, It is a shame they did not install solar pv and also as we have gas in the house a flueless gas fire in the living room

ra200

Thanks for the link some interesting properties on there,

John_Pierpoint wrote: »

Yes I get your point and I had missed the fact that the exhaust air might be considerably below the external ambient temperature.

However if the exhaust is approaching zero the sweaty internal air is useful input to an ice maker - and then the ice and its latent heat has to be melted to get rid of it.

Modern building designs are all about reducing the rate of air change - the mantra is "build tight - ventilate right". It seems to me we have a building where draughts are being dragged in through the various vapour barriers in the depth of winter and being put through a heat pump to produce a large rise in temperature and so an inefficient level of COP.
I have heard people in this new industry talking about "flat building syndrome" where the temperature inside and out of the building is so cold that the heat pump seems to make no progress in heating up the building (more in the context of rich people getting back from a skiing holiday and trying to turn on their heating). It does not really make sense to me but I will agree that my solid fuel heating would take a day and a half to get my home back to 20 degrees, if I were to leave it for a fortnight and come back to internal temperatures of say 10 degrees (I have good thermal gain through the windows as the property is well oriented and reasonably well insulated).

At least give the poor tenant a log burner, so he has the same control over his financial destiny in mid winter, as a gypsy in a caravan. (*)
Most of these eco warriors tend to love their a log burner:

http://www.sustainable-energyacademy.org.uk/superhomes

(*) Woops that would not work as the "active" heat recovery and augmentation pump would gas the occupants by sucking the log burning gasses back down the flue and into the room, I have a feeling that sucking the other way would not work with wood but it would work with the flue gasses from a gas boiler (hopefully CO2 and water with just a trace of NOx and SO2?) !!

1plus1equal3

I have been following ra,s problems on here with his heating system for a few months now. I also live in a new build housing association house, but mine is fitted with a nibe 2005 fighter unit. And i can honestly say the last 18 months have been so stessfull, i live in a 2 bedroom house, and at one time my daily consumption of electricity was 60 units a day, and considering i only get an income of 75 pounds a week , i was going out of my mind with worry. I have lost count of the number of heating engineers that have been round to try and get the system running correctly, each one undoing what has been done by the previous one, and doing what they think is correct, and never has been. i have ranted and raved at the housing association, and i will give them their due, they have always remained polite, but i think they were also at a lost at what to do to put things right. finally last month, they paid for an engineer to come from norwich, and he really did know what he was doing, and since hes been my electric consumption has gone down to between 24 and 32 , which is far better. im still not happy with this figure, because looking on all the nibe sites they all say that having these systems will save money on bills, and i moved from a 4 bedroom house with gas central heating and my combined gas and electric bills were far cheaper then what my nibe system costs to run, and i feel a lot of the time my house is too chilly, but i dare not turn the curve switch up any higher, as it will cost even more. i know nothing about these system, but i sometimes feel that the housing association expect me to learn them inside out, and have gone from saying leave them alone, when i first moved in, to learn how to use it now, which is never going to happen.I think its all well and good building these houses of the future, but like ra, i also have problems with the house itself, but i have asked the housing association to move me to another new build , in the same area, when they have them, and the association have assured me that they wont be using these systems again.so i think i can moan forever about the cost, the noise, the awfull design of the house, which has deterioated terribly, or i can cut my losses and move, as i will never feel at home in this house, and in hindsight, i should of asked more questions about the cost of of these systems to run, i should of realised they are noisy, and i should of known that the lovely colour wood they used to build my house, was going to go mouldy and grey, and look like it was a really rough area, and not in keeping with the surrounding houses.you live and learn, but i would like to say to ra, consider moving, i dont think you will ever be happy with where you are

denial2010

1plus1equal3 wrote: »

finally last month, they paid for an engineer to come from norwich, and he really did know what he was doing, and since hes been my electric consumption has gone down to between 24 and 32

Norwich? Where are you based? Are you also having to deal with Flagship Housing Group?

1plus1equal3

hi denial, im actually in ipswich , and with orwell housing association. but i think they tried so many heating engineers, all supposedly nibe experts, and eventually found the brilliant one called browns in norwich. he has the same system in his own house so knows what hes talking about.

ra200

How is every one getting on with their nibe 360p now the weather has been warmer we have been knocking ours off to save on costs as we do not need it running in this weather,

A couple of things have happened since posting on here last Melin have paid us £500 to pay towards our rather large electric bill but this does not really help as we have another large bill on the way at the end of the month,

We are now looking to private rent as Melin have chosen not to rehouse us and we have told us if we want to me we have to look for a exchange and sort the mess out our self’s which we think is a cheek,

Also apart from the heating issues that we have had the neighbour problems have continued but we have not reported them to Melin homes as last time we did they made us feel so uneasy and we was spoken down to last time we reported them by one of their housing officer ,

Also Melin homes staff have made us out to be lying about the problems we have had with some of theire staff we reported the problems of staff intimidating us and also housing officer throwing a tantrum in our house and they said we are lying,

Also this estate is getting as bad as Melin notorious Taliesin estate in Cwmbran the police are always in and out of our small estate about a week ago around 9pm there was a big police raid there was around 15 police vehicles police dogs police in riot gear people being taken away police taking away cars being impounded it was like something out of the bill the police where at one house for over 24 hours , My partner is now to scared to let the children in and out,

Also we have had vandalism to our property some one on the estate vandalised a lot of our spring flowers and pots and spring hanging baskets so we have now removed every last bedding plant and flowers and plant pots now the small front garden is just a patch of plain mud some idot though it was funny to throw one of the pant pots at the front door during the night and stamp on the bedding plants and smash up some plant pots so this spring and summer our front garden will be plain,

I wish I took the advise I was given about Melin homes housing estates before I moved here we was told they are full of anti-social behaviour problems and drugs and we chose to ignore this and it is a pain to get a repair done how stupid was I to ignore this I learnt my lesson the hard way,
I would strongly advise anyone who is thinking of buying or renting a melin homes property in Cwmbran Pontypool Mountain Road Ebbw Vale Gwent Monmouthshire to do their research first or you will end up with large bill if you have one of these heating systems installed and if you end up on a estate like ours I hope it does not end up with anti-social behaviour problems and police raids so you cannot let your children out,

So we are being forced to leave our home due to the way we have been treated by our landlord and high running costs of the house and also due to vandalism to our property and belongings and we feel the area is unsafe for young children we are the only people with young children on the estate any neighbours on the estate do not have young children they are grown adults I do not think melin homes can see this,

So the sooner we private rent the better ,

ra200

Just to update our nibe is off again due to the fact then even with the warm weather we have had it is not economical to run, Also the last !!!! that we have has again is from their head of construction according to him our bill is high because we do not know how to use the nibe unit, With the amout of bull$sh@t that comes out of that guy mouth since January he would be alright working in Lybia for Gaddaffi ,


Also our landlord melin homes has chosen not to do anything about the problems and it is now almost April and we have found out today they are installing solar pv in properties on our estate to reduce people energy bills but not our house with young children in it we put this down to age discrimination and we have been told that due to our high energy bill which was made by their equipment we should get debit help from shelter Cymru ,


Also we are now fed up of all the Bull$h!t that we have had from Melin homes and some of their staff we have now had enough of them from them accusing us of breaking the nibe to staff threading us and staff trying to belittle us and saying we are lying,
We have not started to put all the information about the nibe system that we have gathered along with all the information I have put together about the C£$p we have had from Melin homes and their staff on a web site I am building,

And I would strongly recommend to anyone thinking of buying or renting a melin / greenhill construction property to do their research first if you do not want the problems we have had from the heating systems to problems with their staff intimidating and threatening to the problems on our housing estate with neighbours houses being raided by the police in riot gear with drug sniffing dogs, Melin have new homes in clos y goedlan garndiffaith Torfaen and clos odyn pentwyn Pontypool woodland street Cwmbran Conway road Pontypool clos sgol bron-y-bryn swffrydd Blaenau mountain road ebbw vale gwent eastville road all of these are melin homes and some have nibe heat pumps if any one reads this who is thinking of buying one or renting like us do your research first or the heating system will cost you a lot to run or if you end up on a estate like ours you might end up like us to afraid to let your children out because of drug raids right on your front door,

We are now looking for the right house to private rent as melin have chosen not to help us and we have had it with all the problems here,