Nibe Fighter 360p ashp costing me loads to run

lovesfarmbpha

Hey...you would need a CoP of a Constant 300% to even match gas. Any exhaust or air source heat pump does NOT achieve a constant CoP (its actually impossible)indeed we know that most Exhaust air heat pumps struggle at anything less than 8C .The CoP is calculated in laboratory conditions and does NOT take into acccount seasonal variance nor calculate the constant fan power.
The CoP the heat pump manufacturers put on and the BRE or MCS is not true of the running CoP in any heat pump unless you live in a Laboratory!
also Gas does not produce NOX (acid rain) electricity does.
We have sent a formal complaint to UKAS and the BRE as we feel they have incorrectly calculated the CoP on the NIBE system....The BRE emailed us back saying how did we get a CoP of 2,6...we said from NIBE 360p manual(worrying reply from the BRE) They also said the guy who calibrated the NIBE 360p has now retired (probably with a fat pay cheque) They have said they did not calibrate it which contradicts what they said before ..fact the BRE is no longer a public organisation it is run by the manufacturers so there you have it..."do as we say"...we also have successfuly got the MCS web site to change both the NIBE (360p & 205)exhaust air heat pumps from the air source heat pump section to where they should be under exhaust air heat pumps....dodgy they were there in the 1st place...
These systems have been put into alot of social housing and I personally feel there is a bit of a cover up going on as people scatter when you question the maths..
But as I said before,,,the maths dont lie and the fact is that if your connected to gas and its a code level 3 build then you should have your prime source as gas not electricity....
The loves farm estate has now taken the complaint also to the housing ombudman....and Im off to read the EN code for the certification of the CoP....
Let me say that I am not anti gren power infact support it greatly but this is a con through and through,,,,,,,hidden by Housing associations and builders alike....but hey...whats new?

jasonoldy69

Hi all. I'm new to the forum, and it's this discussion that has brought me here.

We've just moved into a shared-ownership 2 bed terrace, that has a Nibe Fighter 360p. The house was bought from Longhurst & Havelock HA and they have given us all the documentation explaining how "cheap and eco-friendly" this system is.

I've managed to get our total household usage down to an average of 0.8Kwh, from 1Kwh+. The system has been on 24/7, Spr/Aut mode, fans on Speed I, all the radiators on full, the thermostat between 3/4, lowered the HW temp, no XHW and 0 offset. I've been lowering the heating curve day-by-day, allowing 24hrs to feel the effects - It's currently on 9, from 13, with no noticeable changes. All these settings have been changed with crossed-fingers.

The outside temps have been between 7-11, and we've managed 20 inside with a few hot showers.

I don't believe turning it off is a good idea. If you put your hand over a vent, you can feel the fans sucking cold outside air, as well as the air in the room. So, with it off, that outside air won't be held back from entering the room.

As soon as 2012 arrives, we will be seeking a full demonstration of the unit. The lady that welcomed us on the moving day could only read the starter guide to us and no more, but in her defence she was filling in for someone else.

It annoys me to think that unsuspecting people have been left with a brief instruction manual and misleading electricity bill estimate. If I decided to leave it on winter mode (because it's winter!) with a heating curve of 13, offset -2, we'd be looking at over 200Kw/week!

Also, have you noticed the 360p model has vanished from the Nibe website? I swear it was on there a few weeks back.

lovesfarmbpha

Hi and welcome.
Yes the unit will run at a sort of resonable level in those temps but anything lower than 8C it will struggle...we have a 3 bed semi shared ownership....switching the unit off is a big no no in the winter months......blocking the vents also is a big no no.....mind you some sort of porous filter in the vents (more than what is currently there) may tone down the outside noise from traffic and high wind without stopping the flow of air....be aware that when we took a thermal camera to our new build we found that the house had not been sealed and thus the boiler unit pulling air from the cavity wall space rather than the vents(not fresh air and a damp patch in the kitchen which cost loads) Interesting they are selling the unit to you as eco...are you connected to gas?
We have a facebook page called nibe boiler problems......we try not to rant but sometimes just cant help ourselves :T

1plus1equal3

hi Jason , i dont know if i was reading your artical right, but did you say you are using 8 units of electric a day.I have a different nibe to you , mine is a nibe fighter 2005, and i generally use about 24 units a day, which is an improvement on the previous 2 years. I dont have thermostats in my house, so every thing is run off the curve switch outside, so i havnt got a clue what the temprature in my house is, but im normally chilly. 3 weeks ago my housing association had an engineer come round to scan my underfloor heating, as i am constantly complaining to them that i am cold, and their report back said that i was getting about 20 degrees heat, and the ha says that is all they are obligated to make sure i get. but hopefully they are still going to work with me on this, as i am not going to leave it.

jasonoldy69

Thank you for the Welcome.

lovesfarmbpha wrote: »

Hi and welcome.
Yes the unit will run at a sort of resonable level in those temps but anything lower than 8C it will struggle...we have a 3 bed semi shared ownership....switching the unit off is a big no no in the winter months......blocking the vents also is a big no no.....mind you some sort of porous filter in the vents (more than what is currently there) may tone down the outside noise from traffic and high wind without stopping the flow of air....be aware that when we took a thermal camera to our new build we found that the house had not been sealed and thus the boiler unit pulling air from the cavity wall space rather than the vents(not fresh air and a damp patch in the kitchen which cost loads) Interesting they are selling the unit to you as eco...are you connected to gas?
We have a facebook page called nibe boiler problems......we try not to rant but sometimes just cant help ourselves :T

Yes, we have gas. I almost considered disconnected the gas, thinking what's the point, when everything's on electric (Except the hob).

I think it's amazing that it heats water without actually using anything but air. But, it's cancelled out by the amount of energy used for - I guess - for the pumps and fans.

1plus1equal3 wrote: »

hi Jason , i dont know if i was reading your artical right, but did you say you are using 8 units of electric a day.I have a different nibe to you , mine is a nibe fighter 2005, and i generally use about 24 units a day, which is an improvement on the previous 2 years. I dont have thermostats in my house, so every thing is run off the curve switch outside, so i havnt got a clue what the temprature in my house is, but im normally chilly. 3 weeks ago my housing association had an engineer come round to scan my underfloor heating, as i am constantly complaining to them that i am cold, and their report back said that i was getting about 20 degrees heat, and the ha says that is all they are obligated to make sure i get. but hopefully they are still going to work with me on this, as i am not going to leave it.

We're roughly using an average of 0.8kw/hour, so (0.8 x 24 hours) 19kw/day. That's ~£4/day, over £100/month! If my maths is wrong, please tell me, I'm new to KWh measurements...

Turning the thermostat from low to high, there's no difference, or it could be faulty. I'm treating the curve as a kind-of thermostat now, and the difference in temps can be felt in a few hours. We don't have underfloor heating, and feeling the radiators, I'm very glad.

Now we've hit 2012, I will be getting hold of Longhurst & Havelock to see if this heating can be explained and if any changes can be made. I will return with results as soon as.

Cardew

jasonoldy69 wrote: »

We're roughly using an average of 0.8kw/hour, so (0.8 x 24 hours) 19kw/day. That's ~£4/day, over £100/month! If my maths is wrong, please tell me, I'm new to KWh measurements...

Yes your maths is wrong!

You shouldn't be paying more than 10p to 12p per kWh for electricity so £2 a day is a better estimate.

I suspect you are using the Tier 1 price for electricity in your calculations. Most tariffs have 2 prices - the higher price Tier 1(or primary) unit which is only for a 500 or 900 kWh a year and Tier 2(or secondary units) and you should use the latter in your calculations.

denial2010

jasonoldy69 wrote: »

Turning the thermostat from low to high, there's no difference, or it could be faulty. I'm treating the curve as a kind-of thermostat now, and the difference in temps can be felt in a few hours. We don't have underfloor heating, and feeling the radiators, I'm very glad.

It's not faulty it just has the same problem as mine did... it just wasn't activated. The dial should change the target room temperature on the system. Have you looked at my settings for the unit as we pretty much have an identical setup. 2 Bed Terrace. They are here: http://forums.moneysavingexpert.com/showpost.php?p=43004790&postcount=258

You are however doing exactly what I did. Kept lowing the heat curve to see the lowest you could go. I got to 5! The menus to ensure the RG10 stat are activate are menu 9.1.14 (providing its an RG10) and menu 6.1 and 6.2. Typically 6.1 should of been balanced (mine is balanced to 3.0) and 6.2 activates the controller when its assigned HeatingSystem1.

John_Pierpoint

Most heat pumps boast about their "heuristics".
Translating from ancient Greek, this means they are "clever" and learn how to adjust themselves to balance the variables, like outside temperature and its rate of change, to keep the internal temperature just right. Modern houses with controlled ventilation and brilliant insulation plus thermal mass should take days to heat up and cool and so need a clever heating system to keep them at the "Goldilocks" temperature.

Right back to reality - I very much doubt that this piece of kit has good heuristics and I very much doubt it is installed in modern housing meeting the above standards.
Now we have the "infinite monkeying about" method of setting up the initial settings for the "heuristics".

It sounds to me like trying to pass a driving test without any lessons.

jasonoldy69

Cardew wrote: »

Yes your maths is wrong!

You shouldn't be paying more than 10p to 12p per kWh for electricity so £2 a day is a better estimate.

I suspect you are using the Tier 1 price for electricity in your calculations. Most tariffs have 2 prices - the higher price Tier 1(or primary) unit which is only for a 500 or 900 kWh a year and Tier 2(or secondary units) and you should use the latter in your calculations.

Thanks for pointing that out. I was aware of the two tiers, but I thought it wouldn't be good idea to ignore the higher tier. It would take a good ~40 days, each quarter (our tier 1 is per quarter), to eat through 900kw.

grahamc2003

John_Pierpoint wrote: »

Most heat pumps boast about their "heuristics".
Translating from ancient Greek, this means they are "clever" and learn how to adjust themselves to balance the variables, like outside temperature and its rate of change, to keep the internal temperature just right. Modern houses with controlled ventilation and brilliant insulation plus thermal mass should take days to heat up and cool and so need a clever heating system to keep them at the "Goldilocks" temperature.

Right back to reality - I very much doubt that this piece of kit has good heuristics and I very much doubt it is installed in modern housing meeting the above standards.
Now we have the "infinite monkeying about" method of setting up the initial settings for the "heuristics".

It sounds to me like trying to pass a driving test without any lessons.

Agreed. And for an exhaust heat pump, the parameters are very interconnected - I doubt users could soirt them out, I doubt any housing association knows anything about them, I doubt the installers know much useful, and I doubt the heuristics built in by the manufacturers make much sense unless the house design itself is compatible and the parameters are all within the correct regime. The thermodynamics of exhaust heat pumps is very much more complex than standard heat pumps imv, due to the feedback of the exhaust air temperature onto every other variable (such feedback not existing for 'normal' split HPs).

Starting from the situation that these types of pumps work fine in very colder countries (that's anectdotal, is it true?), we have to see why they often don't appear work here, in a less demanding weather environment. My view is it is the house design and the installaton.

One major advantage of exhaust HPs is the avoidance of defrostind - -i.e. the heat is extract from exhaust air at about 20C (where the damp warm air will condense and run away, instead of depositing ice which causes problems). Seems to me exhaust HPs have problems when the exhaust air is below that warm value (i.e. if being turned on and off a lot, or any other situation where tha house isn't warm enough to exhaust 20C air). This could explain why these HPs have 8/10kW electric heating elements - to get the room warm quickly so it exhausts at 20c so that the heat pump can work as it should (when of course the heating elements aren't needed). The steady state running I expect is fine i.e. extracting say 5kW from exhaust air at 20C isn't too demanding as to air flow rates, I.e. it wouldn't cause a gale through the house). It would rely on all air being exhausted through the proper exhaust, and entering through the proper vents (i.e. no windows open, or leaky doors), and a decent level of insulation.