Nibe Fighter 360p ashp costing me loads to run

John_Pierpoint

Here is a posh private sector attempt do build a home like yours.

It would be interesting to see how an expensive version works.

I have my doubts about overheating in the summer.

I don't see how this passive air-conditioning works in the summer, I wonder if they simply mean fresh air ventilation through a cooker hood filter?.

There is no calculation of thermal gain through the fancy argon filled windows as they should be "U negative" if they face in a southerly direction.
Otherwise there is no indication how heat is to be created in the property.

I have a client with a fancy hear exchanger extractor fan - she finds it a noisy expensive waste of money.

http://www.canterburyecohomes.co.uk/files/ecofeaturesbooklet.pdf

richardc1983

John_Pierpoint wrote: »

Here is a posh private sector attempt do build a home like yours.

It would be interesting to see how an expensive version works.

I have my doubts about overheating in the summer.

I don't see how this passive air-conditioning works in the summer, I wonder if they simply mean fresh air ventilation through a cooker hood filter?.

There is no calculation of thermal gain through the fancy argon filled windows as they should be "U negative" if they face in a southerly direction.
Otherwise there is no indication how heat is to be created in the property.

I have a client with a fancy hear exchanger extractor fan - she finds it a noisy expensive waste of money.

http://www.canterburyecohomes.co.uk/files/ecofeaturesbooklet.pdf

The nibe systems and the one in the link above are not connected to a cooker hood, it removes air from the rooms through ducting but cooker hood is not connected due to grease etc. See here for how the nibe system operates and is connected up.

http://www.nibeonline.com/pdf/411482-1.pdf

The system you have linked to is a true heat recovery ventilation system and compliments the underfloor heating system on page 6. It does not create heat it just collects heat. Air removed from the living space will pass through a heat exchanger which "collects" that heat... the fresh air being sucked in to the building then passes through the other side of the heat echanger and is pre heated by the heat it collected from the air going out. This is a separate edition to the underfloor heating plant. It is designed to save the heat that the heating plant has generated whilst being able to have fresh clean tempered air circulated around the building. In summer it will bypass the heat exchanger (this is known as passive cooling) and it will run in fan mode just pulling fresh air into the building so this is what is classes as "passive cooling" basically it is just like having a window open with a fan in it. Some commercial buildings with air conditioning will use the heat exchanger also to recover the coolness from the stale air inside and then pre cool the air coming being pulled into the building... putting less strain on the air con system. Without it it is like running the air con with the windows open. The building you linked to above has done it the right, whilst it may suffer from overheating in the summer due to being so well insulated and glazing always causes heat build up it will be very efficient in the winter... using the glazing and the sun to create extra heat. Not sure how the underfloor heating is heated gas/electricity but they could improve efficiency by using air source heat pumps that will use the outdoor air to collect heat.

The nibe system is completly different... it is the the only heating system and has the ventilation part included as part of its operation. Without the ventilation part no heat is generated. But unlike the above system you linked to which will use gas/electricity to heat the underfloor heating circuit. The nibe gets its heat from the indoor air. It simply cannot generate enough heat to cope with the natural heat loss and from the side effect of cold air being sucked into the building to replace the air it sucked out.

The Nibe system I would assume is quite efficient in the summer on warm days (some people have reported) as there is plenty of heat generated internally so any fresh air pulled into the building helps cool it down and is welcome. Heating will also be off so all heat generated goes towards heating the hot water.

Heat build up is created through normal activities, cooking, lighting, appliances, people. This heat is then extracted through the ducting which then in turns goes through the heat exchanger, and ends up being multiplied and put back into the heating system.

The problem is you cant keep removing heat from the indoor air in winter as the air it extracts you have cold outside air replacing the air it has sucked out so you are fighting a losing battle trying to build up heat within the property as you are removing heat then just replacing it with the same heat you have removed. You can only increase temperatures inside if you are putting more heat into the property than it is losing otherwise you are wasting energy. This is when the immersion heaters come on. As you are recovering the same heat to heat the property back up. The system would be much better off using indoor air in summer for the heating then in the winter using outdoor air as the heat source. Obviously the system would have to use better compressors and components that are capable of using the low temperature outdoor air. Any ventilation that goes on in the property eg from extractor fans could be ducted to the NIBE to recover the heat you are sucking out. Any fresh air being brought into the property could then be pre heated by this waste heat a true heat recovery system. This system would then be pretty efficient.

Until the system works as above it is a complete failure in the winter as you are sucking the heat back out only to put it back into the building again. For example 3kws of heat sucked out through the duct work... you may put 5kws back into the building but bear in mind the 3kws of heat in the air you have sucked out has to be replaced by fresh air from outside through the trickle vents which is very cold so this will then need heating up so the 2kws extra heat the system has generated out of the 3kws recovered is pointless as it is taken away by the cold air that is being pulled into the building by negative pressure. The internal air down as the heat cannot build up. So really the system is producing 5kws from 3kws of heat but you are not getting anything extra from it due to the cold air that is being pulled back in this takes anything gained away.

If you was to use the outdoor air to recover heat from rather than internal air any heat being put into the building would help raise internal temps as you are not taking it directly out (other than natural loss through roofs, walls etc).

Sorry if I have repeated myself several times but hope it explains how the system works a little clearer.

John_Pierpoint

The only figure I noticed as s struggled through those graphs, which I still don't understand, was 16 degrees.
If the exhaust from the building is below 16 degrees then the unit does not even try to recover heat from it. My bet is that when the exterior temperature is (say) minus five, the interior temperature of this not very airtight building, averages less than 16 degrees all the time, to you might as well have some night storage radiators and at least get the heat from using half price nuclear over night electricity. I don't think they have got much of that left in Sweden but there is more cheap hydro electricity available 24/7 up in Scandinavia.

I think this unit is more to do with keeping a steady stream of ventilation to avoid mould and spores, rather than to achieve cheap heating.

richardc1983

John_Pierpoint wrote: »

The only figure I noticed as s struggled through those graphs, which I still don't understand, was 16 degrees.
If the exhaust from the building is below 16 degrees then the unit does not even try to recover heat from it. My bet is that when the exterior temperature is (say) minus five, the interior temperature of this not very airtight building, averages less than 16 degrees all the time, to you might as well have some night storage radiators and at least get the heat from using half price nuclear over night electricity. I don't think they have got much of that left in Sweden but there is more cheap hydro electricity available 24/7 up in Scandinavia.

I think this unit is more to do with keeping a steady stream of ventilation to avoid mould and spores, rather than to achieve cheap heating.

You are possibly correct a proper air source heat pump will recover heat from air down to -15c the nibe doesn't attempt when internal return air is less than 16c! It's pointless and compressor is not upto the job!

ra200

Had environmental health back here today to reinstall the sound recording equipment,
Also Nibe came and messed about with the 360p again but a usual the sound is just the same and so is the energy consumption,
Melin installed a Nibe RCU 11 http://www.nibe.co.uk/Documents/nibe_co_uk/RCU11.pdf they told me it was to assist with the sound monitoring but by looking at the user manual it is to remotely control the nibe unit via an Ethernet connection or 2G GSM data connection via inserting a sim card but they have not connected the unit to a landline broadband network or via gsm and if they did good luck getting a cell phone signal in this house so it looks like I have been told different,
Also they did not fix the problem of low heat upstairs at all and my children have got to put up with that,
Also have spoken to shelter cymru who gave me the best advice of knocking the unit off and managing without it until we move from this house,
Also Melin sent a contractor who banned from coming to our home due to make out we are lying and accused us of creating a high bill on Melin did this to make us look band in front of Torfaen environmental health I am not happy about this at all,
So we have to manage without the heating system if we are still here in the winter and because Melin refused to move us and we have been told by they to make our own arrangements which we will have to do,
Melin asb team refuse to telephone us and help with asb problems we are constantly telling them there is still asb problems going on here we had some on the weekend again but it is waste of time in phoning them as it is all made out to be our fault and they made out my daughter is a liar & myself and my partner ,

ra200

This morning it was 7.2c outside and upstairs in my house was very cold melin homes still have not fixed this problem and they expect children to sleep in it,

Also i had anti social problems on the weekend again and Melin can not even be bothered to call me back about it,

John_Pierpoint

Is the RCU 11 (Remote Computer Unit type 11?) turned on and monitoring how you are (not) using the heat pump?
As it is you home are they going to allow you read only access to the gizmo?
Are you capable of recording the power the heat pump uses as well as reading your own electric meter?
Have you got at least one of those weather station thermometers that at least reads the room temperature where it is and the temperature outside?
Are you prepared to record these readings perhaps morning noon and night?
What have the boffins done to prove you are not having a laugh, by leaving the doors and windows open and running off the hot water?

I think they should offer you electricity at the night time rate (call it £0.05 a unit) and then accept the challenge to run your heat pump and obtain acceptable indoor temperatures.

John.

PS I've had a look at the manual for the gizmo - any ideas what language the heat pump speaks - is it Scandinavian or German.
(There are not a lot of English instructions, using words starting with a "K".;))

NeverShareAgain

Hi Ra. I have been following this thread as I have a supposedly "eco-home" with one of these Nibe monstrosities in.

I am a working mum with a young daughter, and I have sensory issues which mean I *cannot* tolerate over-heated buildings. We live on the top (2nd) floor of a small apartment block, in a new build housing association flat.

Being as these HA "homes" are often inhabited by people on a tight budget it seems ridiculous that electric heating has been installed in the first place, when GCH is cheaper to run. I feel like my estate has been an experiment that has gone wrong; there have been numerous complaints about Nibe running costs from people, and we all live in different accommodation, from 1 and a half bedroom battery-pigeon flats, to 2/3/4 bedroom beige shoeboxes :A

So, in 18 months, we have had 3 X FOUR HUNDRED POUND + electricity bills. We live simply, have a computer but no
TVs, and do not run the heating. The place is insulated and catches heat from below, and to the sides, plus I prefer not to breathe stupifying, stagnant air.

The engineer came to check the settings and told me that the HA had set it to some generic mode, assuming that all their tenants want the same thing; baking heat and no flow of air, and so he reset it to reflect *my* needs of.. y'know actually opening my windows, and not running the heat except very rarely to take an edge off any chill. Apparently, you are meant to keep all internal doors open.. EFF that, the place is tiny, you do what you can to cut noise and gain some rudimentary privacy. Why bother even installing internal doors? :mad: I do not wish to live in an hermetically-sealed box, that feels like a goldfish bowl.. it would have been nice to have been told this all prior to accepting the tenancy!

Since December 10 I have had the stupid thing switched off at the wall. We use the shower and kettle if we need hot water, and our bills are now a much better £100 per quarter.

The HA are investigating all the complaints but it could take years and there are other things I'd rather do with the cash I work for, like enjoy life with my little girl Why the hell should my environment be dictated by a heater/HA? I want heat I can control instantly, and pay for without sacrificing quality of life.

I've never had this problem with GCH.. it was affordable and easily manageable in terms of temperature, and was designed to be used by people that opened windows and closed doors from time to time! :rotfl:

I really hope you get rehoused Ra, because neither you nor yours need the stress, or expense xx

John_Pierpoint

They don't need the hassle of the annual gas certificate for a start?

NeverShareAgain

John_Pierpoint wrote: »

They don't need the hassle of the annual gas certificate for a start?

The kitchens in every home on the estate are "eco kitchens" and came ready-fitted with a washer/dryer, F/F, and gas oven, gifted to the initial tenants.

So god knows what they are up to. I do think it's some "right-on" experiment that has backfired. The brownfield site used was also "on the edge of develop-ability" and various other waffle there were load of barrels of chemicals here