nibe fighter 1245 running costs

tallaghtjoe

I came across this thread and is very interesting. I have VVM320 heat pump unit. it is currently set at +4. I was advised by the installer to leave it running all the time, rather than have a timer on it. Looking back at the posts here, looks like most have a schedule set up. Is this more economical?

Its a new house (2080sqft) in it since June last year. I had found the house cool at night esp and I now have it moved up to +4, since Christmas. I havent notice a huge difference in the heat in the house, temperature remains between 19 - 20, which I find a little cool. I would prefer the living room at maybe 22, but the thermostat never seems to reach that level and rooms are cool. The bedrooms I have set at 20.

My real problem is the cost of the running of it. Again looking back on the post, my costs alot more that what others seem to be paying. for example Dec - Jan 3591 units were used, my elec bill works out at €755. Oct - Nov 1682 units were used, elec bill was 368. The level was at +2 and +3 during Sep/Nov. Does this seem high for the size of the house? Would I be better setting a schedule? Is there any other way to save some of the costs?

Thanks in advance

deerpark

You sounds a bit like me with vm320, 12kw outdoor unit, MVHR and a 240Msq house thats 18 months old.
I am having the same struggle.
I am putting it down to a combo of some rooms could be better in terms of ease of heating (lots of glass or high ceiling).
I am also putting it down to the hall thermostat being Nibe and seperate from all other stats (neo heatmiser). The nibe system wants an open circuit heating 24x7 and thats in the hall. The hall must be heated to a temp before the other key rooms are e.g. living room catch up. The logic of it is lost on me and is borne by decisions made by the plumber who installed it.

If we want living room at 23, we have to heat the hall to 23.
On this basis the cost of the system to run is high because we are heating parts of the house to a huge level unnecessarily.

I need to have a conversation with our plumber. If possible I would like the open circuit to be the living room, where we like it warm (we have no fireplace or chimney of any type). Then the hall could be adjusted without worrying about the temperature of other rooms.

DP

tallaghtjoe

deerpark wrote: »

You sounds a bit like me with vm320, 12kw outdoor unit, MVHR and a 240Msq house thats 18 months old.
I am having the same struggle.
I am putting it down to a combo of some rooms could be better in terms of ease of heating (lots of glass or high ceiling).
I am also putting it down to the hall thermostat being Nibe and seperate from all other stats (neo heatmiser). The nibe system wants an open circuit heating 24x7 and thats in the hall. The hall must be heated to a temp before the other key rooms are e.g. living room catch up. The logic of it is lost on me and is borne by decisions made by the plumber who installed it.

If we want living room at 23, we have to heat the hall to 23.
On this basis the cost of the system to run is high because we are heating parts of the house to a huge level unnecessarily.

I need to have a conversation with our plumber. If possible I would like the open circuit to be the living room, where we like it warm (we have no fireplace or chimney of any type). Then the hall could be adjusted without worrying about the temperature of other rooms.

DP

That makes sense about the Nibe thermostat in the hallway and I hadnt thought of it like that. I was going to ring the plumber today, but as I dont really know what Im talking about, I thought Id try here first for advise. I will need to contact him, but let me know how you get on with plumber.

JoeA3

deerpark wrote: »

You sounds a bit like me with vm320, 12kw outdoor unit, MVHR and a 240Msq house thats 18 months old.
I am having the same struggle.
I am putting it down to a combo of some rooms could be better in terms of ease of heating (lots of glass or high ceiling).
I am also putting it down to the hall thermostat being Nibe and seperate from all other stats (neo heatmiser). The nibe system wants an open circuit heating 24x7 and thats in the hall. The hall must be heated to a temp before the other key rooms are e.g. living room catch up. The logic of it is lost on me and is borne by decisions made by the plumber who installed it.

If we want living room at 23, we have to heat the hall to 23.
On this basis the cost of the system to run is high because we are heating parts of the house to a huge level unnecessarily.

I need to have a conversation with our plumber. If possible I would like the open circuit to be the living room, where we like it warm (we have no fireplace or chimney of any type). Then the hall could be adjusted without worrying about the temperature of other rooms.

DP

I also have the same Nibe indoor unit, though in my case it’s coupled with a 6kW outdoor unit (F-2040-6) and also a Nibe MHRV.

House is a bit smaller at about 205 sq/m but we do have some very high ceilings!

Overall, very happy with how it’s performing. After a bit of experimenting I have the curve set to 3 with an offset of +1. I meddled with the scheduling a bit a while back but gave up on that and now I just leave it running 24-7. The only thing I schedule is the MHRV. I set it to the minimum setting for a few hours in the evening as the vent above my head in the living room was annoying me.

Anyway, at those settings, I have the house at a constant 21.5-22 degrees throughout. Very comfortable, t-shirt climate basically, even in the atrocious weather we’ve had in the last while.

My plumber also set it up predominantly as an “open loop”. My entire kitchen/dining, hallway and bathrooms are on this open loop. The Nibe stat is in the kitchen/dining. Each bedroom and the living room have their own stats but tbh I’m not sure what they do beyond cut off on he flow to those rooms at the set temp. Essentially the open loop drives everything and if that loop is at 22 degrees well there is no point in setting the living room to 24 degrees because that heat is not available.

Energy consumption is high but not off the scale. Nothing I didn’t expect. Using about 40 kWh per day in the last week or so of the really horrible spell. I’d expect that to settle way back when weather is milder.

Have to say, the MHRV system is a fantastic job. It’s one of those things that you don’t really know what it does until it’s turned off. I had to switch mine off last week as local farmers were spreading slurry. Smell was horrific. Turned it off for 24 hours and you could definitely feel that the house was stuffier and there was condensation on the windows that I’d never seen before. If we put clothes out to dry on a Clothes horse they are dry within a couple of hours. And no moisture in the utility from it. Great job.

In terms of energy costs. Shop around! I switched last month from Electric Ireland to Energia and the savings (look at the unit price per kWh and ignore all the other gimmicks) is very significant.

Edit: just remembered another setting I changed on the Nibe. Disable “additional heating”. That’s basically the immersion heater and it will kick in when temps are like they’ve been the last few weeks. That has a serious appetite for electricity.

hurikane

Have an air source heat pump in the house, it keeps all rooms at 21 degrees. What I miss is, being able to blast the heat. Turn it on and bang, piping hot rads.

JoeA3

hurikane wrote: »

Have an air source heat pump in the house, it keeps all rooms at 21 degrees. What I miss is, being able to blast the heat. Turn it on and bang, piping hot rads.

Yes it’s a very different mindset. You just have to get used to finding a comfortable all-Round temp and stick with it. I know with my system that if I make any adjustments, it would take till Monday afternoon before I’d notice the effect!