NIBE F730 R - Air to Air Heat Pump in new build - good? electricity bills estimate?

DonnieCorko

Hi there,

I am looking at new build apts and I wanted to judge the quality of the energy system they have there (as it might be an indication of cost cuttings elsewhere), how efficient it really will be, and potential energy costs.

The air to air system in the apartments are NIBE F730 R. Is this a good system/setup?

The apt is 80 sq metres, 2 bed.

Any idea what the potential energy bills could be in winter?

The maintenance charge for the apt is high, but if it offsets the electricity cost, id be tempted to buy.

conor_mc

NIBE would be a high-end manufacturer which is a good sign. Impossible to estimate energy bills as it depends on many factors, but should at least be comparable to a gas boiler cost-wise if unit prices are roughly 3:1 (as in, electricity is 3x the unit price of gas).

DonnieCorko

https://www.boards.ie/discussion/comment/122289344#Comment_122289344

Thank you for the reply.

How can I figure out how efficient the place will be before buying? Is there anyway to know?

For example, this is air to air, there is also some air to water systems. Which is better?

One friend bought a new build last year and it has GFCH, which I was very surprised by.

conor_mc

personally, I’d prefer a2a in a smaller property like an apartment. Your main protection against efficiency being undermined is at snagging stage, get someone who knows what they’re doing re efficiency of the building fabric, and test the system for any noise/vibration etc caused by poor installation.

TerraSolis

The F730 R is an exhaust air heat pump. These are typically only suitable in efficient low-heat load buildings. Generally, I would see it as a positive sign for bills and running costs. The F730R includes ventilation which is a good sign that you won't have condensation issues which are synonymous with so many Irish apartments.

https://www.boards.ie/discussion/2058356834/nibe-f730-r-air-to-air-heat-pump-in-new-build-good-electricity-bills-estimate

DonnieCorko

Thank you both for the replies.

https://www.boards.ie/discussion/comment/122290176#Comment_122290176

Any recommendations on someone for this? What role would they be? QS?

https://www.boards.ie/discussion/comment/122290700#Comment_122290700

That's great to know, thank you.

Would the fact its a first floor apt with only a car park beneath it cause issues do you think? In terms of increasing the cost of heating the place etc?

DonnieCorko

https://www.boards.ie/discussion/comment/122290700#Comment_122290700

Do you think eleccy costs in winter could be around 100 per month in an apt with this system? This would be a big plus in terms of buying the apt.

TerraSolis

https://www.boards.ie/discussion/comment/122290967#Comment_122290967

RE Car-park, mid-floor apartments can benefit from reduced heat loss (as walls border warm neighbours' apartments rather than the outdoors', but really it's a function of whatever insulation is in place. Do you have a BER cert? I could give you a good stab estimate if you can get the HLI (Heat Loss Indicator) from the BER.

DonnieCorko

No BER cert but these are the specifications. Can see it under Energy Efficiency and the type of system under Utility Room.

I understand that mid floors would have benefits in terms of neighbours heat etc but what you said about insulation is also what makes me think it could be very cheap to heat.

DonnieCorko

I have a friend who bought a 2 bed ground floor apt in a duplex type setup. He has this system modulair 180L TUMA 00180 LFC - which seems to be similar to the one I mentioned above and I think he has said it was costing him 10+ euro a day in winter to heat the place, which is extortionate.

TerraSolis

Being conservative, at an A3 BER, the building is expected to consume < 50kWh per sqm per year all in. This would put you at about 4000 kWh per year, averaging 333.33 kWh per month. In a new apartment this will all be from electricity. Assuming an average tariff of 30c per kWh, you're talking 100 euros per month with heating included (plus the standard charge).

You can expect deviations from this figure based on your own behavior of course. For example, leaving the window open (instead of boosting the ventilation via the NIBE unit) and heavy use of a regular (non- heatpump) dryer would drive these up of course.

But actually, as a rough benchmark, you are indeed talking about 100ish beans per month. More likely this would be around 70 per month in the summer and 130 per month in the winter or so.

DonnieCorko

https://www.boards.ie/discussion/comment/122291105#Comment_122291105

Ok this is great info, thanks very much. I looked at my current gas and eleccy bills and its around 2500 per year before govt subsidies so looks like 1k in savings there. Much appreciated for your input.

Any idea about my friends system compared to the NIBE? Why would his be so high, bar maybe him over estimating the costs.

TerraSolis

https://www.boards.ie/discussion/comment/122291155#Comment_122291155

A lot of people get a shock moving to heat pumps because all electricity + heat is then on the one bill. In contrast, people often psych themselves up for a week before calling the oil or kerosene crowd to come top up the tank, so they're in a different headspace.

It is possible to configure a heat pump with crappy settings (high flow temperatures, no weather compensation) such that the efficiency falls off a cliff. If you encounter this problem, you have the opportunity to do some internet research and to correct the settings. The NIBE unit will have all the right possible settings that you can change if you need to. Has your friend look into this?

Other possibilities include:

Behavioral influence (does your mate open the windows for half an hour a day in the winter? Many people have it in their heads that they need to, even when moving into well ventilated buildings with plenty of fresh air circulation. Do they use a lot of hot water?)

Electricity Tariff (does your mate ever switch? Are they stuck on a tariff with expired discount when there is much cheaper available?) 10 euro a day to heat implies 33kWh elec used at 30c/kWh, implying about 100kWh of heat demand (assuming COP of 3). Which is an average heating load of 4kW constant throughout the day. That's frankly way too high for a modern apartment, which should be about half that.

Also, the unit your mate has is made by Joule, who would be below the NIBE in the ranks for sure.

DonnieCorko

https://www.boards.ie/discussion/comment/122291301#Comment_122291301

Thanks very much again for the reply.

I did mention to him that perhaps he should get an expert to look in to this. He is only in the house since December so I doubt he is on an older electricity tariff, as he was duel fuel previously.

I am also looking at new builds in the same estate as he is, so it would also be a similar system. I have attached an image of the setup for the duplexs below, which is what I would be looking at versus his 2 bed ground floor apt. Any idea what kind of setup this is? The specs make it sound the same as in the NIBE apt.

I would imagine that the difference between NIBE and Modulair shouldn't be THAT much though to explain the difference, or affect the heating costs for the NIBE 2 bed apt versus the 2 bed ground floor apt that he is in, so I suspect its either user error or overestimating his actual costs (perhaps he didnt do a meter read).

Exiled Rebel

It appears to be a high spec apartment you're considering with nibe a2a, nordan windows and Roca sanitary ware, all of which are high end brands. The developer hasn't skimped on these elements which would give me confidence in the build quality.

DonnieCorko

https://www.boards.ie/discussion/comment/122293350#Comment_122293350

Thanks for the reply.

One concern I had was noise. The apt we are looking at is on the ground floor, right next to the two doors that everyone in the block would need to enter to access the lifts.

We tested it out noise wise by standing in the apt and another person opening and closing the door outside, and we could hear the door slamming pretty loudly. Granted the apt was empty so sound would travel.

Would this be expected in even a well soundproofer apartment do you reckon? I know the specs say concrete floors and high performance party walls, but they didn't sound too high performance to me :-)

Exiled Rebel

https://www.boards.ie/discussion/comment/122293780#Comment_122293780

Personally that would drive me mad. I lived in an apartment in London a few years ago and for about two hours in the evening flights taking off from Heathrow used to bank to the right as they passed over our house with the engines at full throttle. It did my fricken head in...so much so it was one of the reasons we left after the 12 month lease was up.

DonnieCorko

https://www.boards.ie/discussion/comment/122294150#Comment_122294150

Yes that is what I am thinking too. Gf said its fine but I think she is the one who would actually go crazy with it eventually.

It also made me realise I am slamming the apartment door when I leave in my own place. Feel bad for the ground floor apt now :-(