Nibe Fighter 360p ashp costing me loads to run

denial2010

lovesfarmbpha wrote: »

Thats really low power consumption.
Is that just the system or the entire house?
Can I ask...is your nibe 360p your only heat source?
The fan alone will use on average 4.2kw a day on normal fan speed and that before the compressor at 550watts kicks in to heat the water..so your 6.17Kwh suggests amazing results.....do you shower once a day
What size place do you have?
How many people live in the home?
Where you getting your daily power consumption readings from?

sorry for all the questions but with figures like that you must be doing something right...and we want to know what
We are EDF as well we use econmy 7 (the one where after 9pm the power is off peak till 6am)mainly coz we work all day and kids at school .To be honest there is not much difference in all the tarrifs....you may save £10 if your lucky....
we have a 3 bed semi ,one year old which is pretty air tight (now).
Our average energy consumption this week (Nibe on autumn/spring setting) is between 19 kw to 25 kw so not to bad heating on as cold.
The house is a temp of about 21C to 23C.

If you flick back through the thread, I posted the settings I am using. My house is maintained to between 19C-20C. I'll try and answer all of your questions...

The figures I quoted is consumption for the entire house. The Nibe 360P is the only heat source. When the Nibe guy came out, he put an air flow meter on all the fans and found they were running too fast, so slowed them all down. I shower once a day in the morning and its a 2 bed house. 79m2 with an upstairs and downstairs. I never open the windows, sort of defeats the point of MVHR. Up until September it was just me. Now a friend has moved in and the usage hasn't really increased much. I have an wireless energy meter monitoring the entire house supply. But those figures quoted are based on what I've been billed using the actual meter readings.

In terms of tariff and the Nibe. I think Economy 7 is a waste of time. The unit will use electricity whenever it feels like it. However, reading the installation manual (I have done serveral times at length) the Nibe needs to be told its on Economy 7 and will adjust accordingly. I am also with EDF Energy. I am on one of their online tariffs (number 7 I think). I pay 24p daily standing charge and 10p per KW/h. I'm not 100% sure if its the right tariff for the unit, but once I've got a years figures in I can work it out. I chose a daily charge tariff with a cheaper unit price to offset the winter running costs. Also EDF were offering £100 credit and £80 cashback through Quidco on that tariff. So actually its only cost £100 so far this year!

Now to me 21C-23C is too hot. That would suggest to me your heating curve is slightly too high. I'm happy to leave mine at 19C-20C using a heat curve of 5 (... that's way off the "recommended" heat curve of 13 from Nibe!). If I feel a little cold in the evening I just put a jumper on... That's quite rare to be honest!

Here is a link to my settings by the way: http://forums.moneysavingexpert.com/showpost.php?p=43004790&postcount=258

Just a general observation on this unit from when its not set up correctly. It will be forever making a noise day and night with the compressor going, etc. Also the flow temperature will be quite high. Since mine has been tweaked, the unit spends most of the time silent (just as well as Persimmon installed it in the bedroom cupboard!). When its silent and the circulation pump is just running, it uses peanuts! The flow temperature is normally low 20's.

denial2010

Also, just checked the past 7 days consumption on the wireless energy monitor for comparison. I switched the system into Spring/Autumn mode about 3 weeks ago. It's been using between 12KW/h - 15KW/h per day.

lovesfarmbpha

cheers for the info....it helps us and others understand where its working and where its not.
22-23C ...yep agree its warm but we have two young children(7&8).
We have 4 showers in a day.
I think we have hit the sweet spot interms of energy consumption at round about 20 units to max 25 units a day(whole house).
We have had NIBE round so many times on this estate that I think they have set up shop here .....I have moved the fan to its lowest flow inside the machine which draw on 100v at 1.25 amps,,,so about 125w....I have set the fan to go to low flow after 10am till around 17.30 hours so the ventilation kicks in for morning showers breakfast etc and when we get back home from work ..I then switch the fan back to one (manualy on an 8 hour time set)during late evening so the fan is nice and silent.
I have noticed that when its cold outside (night times) having the fan high brings in the chill from the vents so Im testing keeping the fans low for cold snaps or overnight see if iyt works and so far I would say it does.
I have seen the fans set really high on these systems even mine was set really high by the NIBE guy.....(understand building vent regs)
We also laid extra loft insulation and over the duct(pipe) work in the loft as the installer had decided not to follwow the design but lay most of the duct in the loft with only 1mm of insulation foil on it...that has helped the heat capture loads..
Thanks fo your time....and I'm sure from others also
We have a FB page called NIBE boiler problems that has had over 50,000 hits in under 6 months....
The Univeristy of Cambridge,Engineering Dept,Hopkinson Labs are testing heat pumps (the outside types) at the mo...They are interested in visiting the units on the estate to get field readings..
It terms of effciency the sales pitch says its a COP of 2.6...but they only calculate the compressor power (550 single phase)not the fan running for 24 hours....so an avearge fan setting of 140V at 1.25amps will consume 175Watts,which is 4.2 KWh every 24 hours.............just for the fan to run...which if this is added to the calculation of the compressor CoP (effeciency) would make it around a 2.1 score (2.5 score gives it an MCS accreditation).
The NIBE score 2.6 just on the compressor...shady me thinks.....plus the RHI dimissed these systmes as renewable which kind of confirms the MCS accreditation is uhhhmmm...unlike air source heat pumps which will get the RHI payment.
The RHI is not paying out for any make of Exhaust air pump....for those who still think they r the bees knees...
Fact is the owners of these systems are fast becoming super knowlegable about these systems which is good as the installers can be ...well lets say a little STUPID.....


Can I ask are you connected to the gas network?
We are in ....Cambridgshire/Bedfordshire..

denial2010

lovesfarmbpha wrote: »

cheers for the info....it helps us and others understand where its working and where its not.
22-23C ...yep agree its warm but we have two young children(7&8).
We have 4 showers in a day.
I think we have hit the sweet spot interms of energy consumption at round about 20 units to max 25 units a day(whole house).
We have had NIBE round so many times on this estate that I think they have set up shop here .....I have moved the fan to its lowest flow inside the machine which draw on 100v at 1.25 amps,,,so about 125w....I have set the fan to go to low flow after 10am till around 17.30 hours so the ventilation kicks in for morning showers breakfast etc and when we get back home from work ..I then switch the fan back to one (manualy on an 8 hour time set)during late evening so the fan is nice and silent.
I have noticed that when its cold outside (night times) having the fan high brings in the chill from the vents so Im testing keeping the fans low for cold snaps or overnight see if iyt works and so far I would say it does.
I have seen the fmas set really high on these systems even mine was set really high by the NIBE guy.....
We also laid extra loft insulation over the duct(pipe) work in the loft as the installer had decided not to follwo the design but lay most of it in the loft with only 1mm of insulation foil on it...that has helped the heat capture loads..
Thanks fo your time....and I'm sure from others also
We have a FB page called NIBE boiler problems that has had over 50,000 hits in under 6 months....
The Univeristy of Cambridge,Engineering Dept,Hopkinson Labs are testing heat pumps (the outside types) at the mo...They are interested in visiting the units on the estate to get field readings..

Can I ask are you connected to the gas network?
We are in ....Cambridgshire/Bedfordshire..

I am indeed connected to the mains gas network (only the hob uses it)... Gas bills are pretty much peanuts for the quater. So my total energy costs are pretty much what I quoted futhur up plus a couple of quid. I'm a little bit furthur down the A14 in Sunny Suffolk!

lovesfarmbpha

Still struggling to understand how you have managed to achieve 6Kwh per day ,,,,,,reason is even if you set the the fan speed inside the machine(normally done by a qualified person as involves changing electrical connections )to the lowest possible speed it would be 100volts at 1.25 amps,,,which over 24hours would be 3kw just for the fan...the compressor uses 550w and we know that if you dont use the hotwater the compreesor will run 3 to four times in a 24 hour period for circa 2 hours each time....so lets take the 3 times to give it a chance....that would mean 3,300Kw for a 24 gour period....total 6.3 Kwh per day.....so that means that nothing else was running in your home...no fridge...no lights...no hot water usage....nothing????????
was this a estimated bill?
dont forget that at an average of 10p per kwh for electricity lets say you paid 60p for that amazing day you would have been better off with gas which for the same power would have been a third of the price if not more than that...not to forget that electricty releases 2.9 more times CO2 than gas...so you have not saved money nor the planet....
Did you say permissions built it?
really struggling to understand how you tweaked 6Kwh for a day...would love to get a whole house usage to 6Kw a day!.

lovesfarmbpha

sorry we are on eco 20:20....edf

lovesfarmbpha

richardc1983 wrote: »

It makes no difference if the building is airtight you have air vents which supply air from outside to replace the air its sucking out.

Sure the vents provide fresh air however this fresh air intake needs to be controled (as in only from the air vents) In our new home they had not sealed the timber frame sole plate to the masonary so the NIBE was sucking the "new " air from the cavity walls (DAMP AIR) as it was the larger area(air is like water will take the path of least resistance) it was horrible...since they have sealed the house properly now the home requires less heat to keep warm...NIBE themselves say lower than 5m3 etc etc is ideal .......
as you stated in your previous post the venst draw in cold air...any larger non sealed areas will do the same ...if they are greater than the vents then you will have a problem as we did.
An air tight house is imperitive ...any way...if its not then there is really no need for the 24 hour mechanical ventialtion to run...and in affect if you have a house that already passivley vents its self then all you would need is the compressor and fan to run only when heat was needed....or just buy a ASHP......

denial2010

lovesfarmbpha wrote: »

Still struggling to understand how you have managed to achieve 6Kwh per day ,,,,,,reason is even if you set the the fan speed inside the machine(normally done by a qualified person as involves changing electrical connections )to the lowest possible speed it would be 100volts at 1.25 amps,,,which over 24hours would be 3kw just for the fan...the compressor uses 550w and we know that if you dont use the hotwater the compreesor will run 3 to four times in a 24 hour period for circa 2 hours each time....so lets take the 3 times to give it a chance....that would mean 3,300Kw for a 24 gour period....total 6.3 Kwh per day.....so that means that nothing else was running in your home...no fridge...no lights...no hot water usage....nothing????????
was this a estimated bill?
dont forget that at an average of 10p per kwh for electricity lets say you paid 60p for that amazing day you would have been better off with gas which for the same power would have been a third of the price if not more than that...not to forget that electricty releases 2.9 more times CO2 than gas...so you have not saved money nor the planet....
Did you say permissions built it?
really struggling to understand how you tweaked 6Kwh for a day...would love to get a whole house usage to 6Kw a day!.

The compressor doesn't normally run for that long. I will time it next time I hear it start up. No estimated bill, that is using the meter readings from the bill (which are actual figures). I don't mind scanning in my bills to show you if don't believe me! House used 11.96KW/h yesterday according to the wireless energy monitor. And yes Persimmon built the house.

lovesfarmbpha

No need for scanning bills ..
We got same wireless thingy looking at our consumption also...
We are going to wire up monitoring devices to the NIBE so we can see what its actually using and when.....log it all etc..
In theory it should use no more than 10KW a day...
Dont forget the immersion will kick in every 14days to raise the hot water to 60C to kill legionaries disease.....and the immersion runs at 6KW (mind you only need 20mis to boost it to 60C from 40C)

denial2010

lovesfarmbpha wrote: »

No need for scanning bills ..
We got same wireless thingy looking at our consumption also...
We are going to wire up monitoring devices to the NIBE so we can see what its actually using and when.....log it all etc..
In theory it should use no more than 10KW a day...
Dont forget the immersion will kick in every 14days to raise the hot water to 60C to kill legionaries disease.....and the immersion runs at 6KW (mind you only need 20mis to boost it to 60C from 40C)

What heat curve and offset are you running at the moment? Just rads or underfloor heating? Also is your system balanced and the RG10 controller (thermostat) activated correctly? I.e - when you turn the dial on the thermostat does it adjust the target temperature on the system?

Those were the issues with my system. As well as the fans operating too fast. I think the guy also adjust the minimum temperature where it just relies on the emmersion from 5 degrees to 0. Have you set setback times too?