Heat Pumps - post here.

Hello Thread people. I am new to Boards.IE so go easy on me. I hope I am posting in the corect Forum. Apologies if not. Please excuse the long post, but I need to inmpart and request some information.

I have recently moved into a 370 sq meter Dorma bungalow with radiators in all rooms and Zoning. Itis BER rated A2 with good roof and reasonable cavity wall insulation and double glazing.

I have two Mitsubishi 14Kw heat pumps and a 170 litre hot water cylinder. The cylinder is topped up by 19x .4kw so;ar panels.

All works fine in the summer with the heating off but when heating is selcted my bills are extremely high with an average of 800-900 euro bi-monthly and with rads not getting particularly warm with temp set to 19 degrees or lower.

I am based in South East Ireland and a reputable renewables company (air and ground only) has quoted me €30K to get my ssytem working properly which includes upgrading the rads to run with lower flow temperatures (45 out and 40 return), a buffer tank, removing the zoning and increasing size of the hot water cylinder and getting the heat exchangers to run weather biased in cascade rather than in in parallel. I have no problem with their recommendations apart from ofcourse the cost which amounts to what the original install would have cost. The other issue is that even with this expenditure ther is no guarantee that I will be roastie toastie....affordably.

I would like to look at a hybrid system. Something like a pellet boiler / heat pump/ buffer tank combination that doesnt require the costs of radiator upgrading and would hopefully achieve hotter radiator temps in winter whilst being able to turn off in the summer months.

My biggest problem is that I am new to Ireland and as soon as I Google "Proffesional Hybrid system installers" there is a dearth of information out there as to reputable Companies that could (importantly) quantify and install and maintain such a sytem.

Is there anyone out there that has had a hybrid sytem fitted professionally and well and can comment on such an install or know of anyone that could (whilst observing Forum protocols) ?

Any helpful comments taken with thanks.

All the best

Madgollfaddict.

MOD NOTE. As suggested below, I'll move this thread.

If two 14kw heat pumps can't heat the house then you have a major heat loss issue and no matter what heating system you install it is going to be very expensive to run.

That’s crazy. Not wishing to offend but are you really sure you have 28kW of heat pump? Your house should be like a sauna with that volume of heat.

Thats even crazier than the 28kW of heat pumps. It sounds like they are doing a rip and replace which is complete overkill. Assuming the heat pump is in good order they should be able to get it working for a fraction of that.

I have the same size house as you and have a 12kW heat pump. It does the job fine.

I wonder is your system running in failover mode (i.e immersion heating). That would explain it.

My advice is get another one or two installers out to take a look and fix what you have.

Forget hybrid, that’s just adding more expense and complication and maintenance and things to go wrong.

@Madgolfaddict

First things first you need to need to put an energy monitor on those heat pumps to live monitor them so you can see when they are coming on and off. Don’t know how tech savvy you are but you could put a ShellyEM on the circuit and set up Home Assistant but there are other options

See my graph below from last November I can see exactly when the heat pump is coming on, if I notice that it’s a nice day and it shouldn’t be coming on then I will look into it. Normally its one of my young fellas has his window wide open and its then calling for heat. Or the missus ramped the room temp up to 22-23 degs ☹

You are saying your bills are 800-900 in the heating season, but don’t forget the unit price of elect has doubled in the last 2 years so everyone’s bills are high. You have a big house so will require more heat than the average joe.

I wouldn’t bother with complicated hybrid systems, keep it simple at least you will only have one thing to worry about going wrong. Also I wouldn’t start shelling out any big money yet until you understand what is driving the consumption

I have also put in a graph below of my rolling 7-day average consumption of my heat pump over the last year, I live in a A1 230m2 house. During the summer I am 4-6 kWh/day during the winter that about 20-25 kWh/day. That big spike was that really cold snap last December when we had days reaching -5deg for a week or two.

Here is a typical day for me in late november last year, the yellow line is the HP, most of this is showers but there is a half hour in the middle of the night.

Hi

The system is supplied by Brunner Products - Heating center (brunner.eu).. I looked at it. it's expensive. Bear in mind if you upgrade your insulation as well as underfloor heating you will use less and less the open /stove. We're 10 years in with an Air-source heatpump and we only use the stove in the late autumn when the heatpump is not heating (yet) . Once the heating is on and we light a fire in the stove the house downstairs will get hot ( 23C) (this is due to latent heat in the floor before someone comments .. heatpump does not know about my need to light a fire 😋 ) . The concept of having a Thermal store to use solar heat, heat-pump and stoves is great but you need to calculate out your needs carefully. (And then calculate your savings v cost , ROI .. )

How easy are the Shelly din-rail power monitoring devices, e.g. Shelly Pro 1PM, to install for a non-electrician?

You mentioned other options??

Do you have a graph of your heat pump from a normal cold winters day? Like 5-10C outside.

Here is a graph from the 26th Jan 2023 the mean air temp on this day was 5.1c for the entire day never got about 7 and went as low as 3.3 deg. I cant differentiate between heating and hot water unfortunatley, but at night up until 7am its all heating. From 7am to 9 its proably showers, and again after 6pm there woudl be a coupld of showers again also. The HP consumed 40kWh for this day which is a lot I presume...

For the 22nd Jan 2023 the average day temp was 9 deg so still a cold day (never got above 10deg) a few degs makes a big difference (also if its very windy) for this day the HP only used 20 kWh and a lot of this is probaly showers.

Do you have a buffer tank or zoned heating controls? Is it using weather compensation?

I dare say it's important to park the bill. It can take a week or two of getting used to but all that matters is average KW per hour or per day. If you think in KW you can act faster to adapt system settings and build a feel for the pump. Elec company changes their fees or fee structure and comparisons with peers or historic performance are immediately redundant.

I did a write up of how i installed the ShellyEMs in another thread, here is the link

Power / Electricity Apps? — boards.ie - Now Ye're Talkin'

Please direct message me some names for ground loop pump installers and type of pump they do.