Heat Pump Running Costs

staples7

https://www.boards.ie/discussion/comment/121568833#Comment_121568833

2421KWH for the year, 733 of this was hot water. A2 house 260m2

Bar the hot water, heating was exclusively on night rate @ 14c inc VAT

(Water heating can come on at any time) Mitsubishi Ecodan HP, during winter maintains a pretty constant 20' but could dip to 19' on freezing mornings but would recover back to 20'+

2022 was 2559Kwh

2021 was 2774Kwh

Pretty consistent and very happy with cost, your looking at under E500 to heat the house and provide constant hot water for the year.

zoom_cool

House is 200m2 two storey extensively renovated UFH down stairs Alu Rads upstairs used in 2023 2163Kwh that includes Hot water Stats are at 20/21 downstairs and 19 Upstairs hope this helps.

staples7

HP running at about 20kw per day this cold week, could prob do with a bump as ive seen 19' by night in the house.

mitresize5

Can anyone tell me where or how I get the number of kilo Watts used by the heat pump?

First full billing cycle since we moved into renovated A2 retro fit and got a nasty surprise 😮

dominatinMC

https://www.boards.ie/discussion/comment/121628148#Comment_121628148

Very low usage, I'm averaging about 30kWh at the moment due to cold spell.

dominatinMC

https://www.boards.ie/discussion/comment/121632080#Comment_121632080

Depends on the brand of pump, but usually you should be able to access this type of information from an interface/panel on the indoor unit.

How much was your bill? If you haven't had a heat pump before, it will take a while to fine tune it and get it right for your house

TimHorton

Lad I know has a Geothermal System from 10 + years ago , His bills are massive and we looked at his half hourly usage the other day (recent smart meter installed) and this week he is using 150 to 180 units per day ! What can he do to lower the usage - Installer not interested in resolving.

Eleusis

https://www.boards.ie/discussion/comment/121632565#Comment_121632565

The half hour usage on esbn site are weird. You have to half them to get accurate reading. (Unless you did that already)?

Even after halving it, that's high though.

mitresize5

Thanks, the bill was 860e

I'll look at the control panel to try and get the usage.

First heat pump alright. Any suggestions for fine tuning it.

The one thing that jumps out is it maybe heating the hot water too hot. Is this a 'thing'? In the shower the temperature of the water is too hot when the wheel is turned just a little over half way.

graememk

https://www.boards.ie/discussion/comment/121632589#Comment_121632589

Regarding bill, the amount is what everyone sees, but what was the actual use, did you have an estimated bill before hand?

As it's a retrofit, did you live in the house before hand? (If you did what did you spend on gas/oil before)

If you have a smart meter, you can see your half hourly use on esb networks website (separate from your supplier) - if you pull out the data file, you need to divide the power by 2 to get the kWh(units on electricity bill)

Do you have radiators or underfloor?

Is the house hot enough?

Regarding Domestic hot water(DHW), the shower are thermostatic, it will mix the hot and cold to the set temperature, the kitchen tap would be a better indication of how hot the water is.

I'm sure there's room to improve.. but if you can't measure, you can't improve.

Eleusis

https://www.boards.ie/discussion/comment/121632589#Comment_121632589

Yea it's really hard to know how to help without you providing as much info as you can.

If house is block then it is going to use a lot in the 1st days to get building fabric up to temp. Timber frame much faster(but cools faster too).

House size?

Underfloor/rads?

Heat pump: brand? Split/mono? Size?

What temp is dhw set to heat to?

Unit usage before and after renovation(not how much the bill was) . Ideally compare to unit usage of the same periodbut the year before. Or go into heat pump controller to find your usage. All heat pumps should show this.

Cyrus

We used 73kwh in the house yesterday (no car charging), thats the highest i have seen it since i started tracking.

I dont have a discrete HP monitor yet but on more temperate days (earlier in Jan) we would use around 40khw so all that extra is HP for sure.

I had to increase the flow temps as it was struggling to get the house up to temp downstairs where we have UFH (and we installed solid wood floors over it so less efficient)

ECO_Mental

My 7 day average is up around 30 kWh/day and that includes DHW eg showers which is pretty good. No where near as much as December 22 (42kWh/day) where we had another really cold spell but that was a lot more windy. What I find if its windy it sucks a lot more heat out but this spell of weather is way more settled.

johndoe11

46kwh for me on heating yesterday with air/water heat pump 250sq metre house, probably be similar if not more today. Considering it was barely above 0, I don't think it's too bad.

676 kwh on heating and DHW used since the start of January. House is maintained at 21c downstairs and seems to hold this even at - 6.1c last night. I've got rid of setback during the day as house was getting cold.

idc

Hoping this does not derail thread but what kind of electricity plan would most heat pump users have. Like is there a call for electricity for heatpump 24/7 or can the majority of heating been done via a day/night plan thus most of the kWh used is at least at a cheaper rate?

Similarly would it crazy to switch to smart plan with like 3-4 hour EV cheap rate but higher day rate as you'd be using expensive day rate for most of the winter to power heatpump?

johndoe11

I'm on smart plan but not the cheap EV night window rate. I am now leaving it running the same temp 24hr, weather compensated, running more at night didnt work for me. It will typically use much less during the day during normal winter weather, but the current cold spell means its running much more during the day.

I have solar and 15kwh battery so I can switch a good bit to night rate.

I think you'd need a very big battery to make the EV cheap rate work with a heat pump.

Mr Q

https://www.boards.ie/discussion/comment/121634227#Comment_121634227

My setup is similar to yours. I just let the HP run 24hrs and the DHW at night rate only.

I can get the full day from the battery so it's all night rate cost anyway. With some losses in the cycle.

I found it used more kWh per day if I heated the house more at night than letting it do it evenly through the day.

dominatinMC

https://www.boards.ie/discussion/comment/121633214#Comment_121633214

Similar usage here. 245 m2 house, living areas between 22-21 degC and bedrooms etc at 19 degC.

Agree completely on the wind factor. Although I've a well insulated house, it's a very exposed site and when the storms hit, the house takes the brunt of them and I see the usage go up. Hence, not looking forward to this weekend!

graememk

https://www.boards.ie/discussion/comment/121634474#Comment_121634474

I suppose if you didn't have a big battery, using more to preheat at night is better cost wise.

But if you have the battery, it doesn't matter to preheat at night. As long as you can stay on battery power.

johndoe11

https://www.boards.ie/discussion/comment/121634474#Comment_121634474

You must have a big battery. For the last few weeks, I'd be a good bit shy of getting through the day rate hours even with a 15kw battery. I'm aiming to add another 15kw before next winter, that should cover me most days then.

newhouse87

Approx 28-30 this snap including dhw. Running fixed flow 31 9am to 10pm. House cools to 19/20 overnight and back to 21/22 by midday. Last winter would have been using 60+ on these days with installer settings 242sqm ufh.

Mr Q

https://www.boards.ie/discussion/comment/121634599#Comment_121634599

30kWh battery, usable about 24kWh currently.

Highest usage this week was 28kWh for the heating system over 24hrs. That is from a meter in a sub board that covers the HP, stats and pumps.

I'm not sure how much of that was DHW but the battery is comfortably covering the 15 hours of day rate. I do have solar to top it up but it is East/West and has only averaged 4kWh per day for January.

MicktheMan

https://www.boards.ie/discussion/comment/121634630#Comment_121634630

Last winter would have been using 60+ on these days with installer settings 242sqm ufh.

Do you mind me asking what were the errant installer settings?

newhouse87

https://www.boards.ie/discussion/comment/121634997#Comment_121634997

Wc set too high. My flow last winter would have been 40+ in these conditions, now 31. Not quite installer but I feel running house as 1 zone has made huge improvement too. Hall used be cold last winter but now flow going All over as all loops open and whole house feels Much warmer. Employing setback overnight as my house retains heat v well helps too.

Cyrus

How do you open the zones?

newhouse87

https://www.boards.ie/discussion/comment/121635216#Comment_121635216

Remove actuator heads. Means when heat called for, all the areas of house will receive heat.

graememk

https://www.boards.ie/discussion/comment/121635222#Comment_121635222

Also turn the relevent thermostats of the removed heads down as low as possible so it doesn't generate a false all for heat

newhouse87

https://www.boards.ie/discussion/comment/121635250#Comment_121635250

All depends what way they want to run. Personally using 1 timed stat works for me, all other stats just tell me what temperature is in the room as I have then down @ 15 so will never call. Some people open zones but still use each room as stat on/off.

Eleusis

Using approx 15kwh per day for heating and 3.5kwh for hot water. 220m2 recently renovated. Inside temps around 20-21 degrees. Running weather comp. Flows approx 27 degrees

hero25

how does one adjust the flow setting/temperature?