Heat Pumps - post here.

Urban plumber says no problem fitting under window or slightly over a manhole

hi folks - what are peoples views on the heatpump grant? i got a quote yesterday from one place to put in a heatpump and use the existing cylinder - was 6.5k after the grant and other discounts.. they priced the heatpump at 15k which sounds way over the top. I know my plumber isnt on the grant scheme setup but im wondering are places just adding the grant onto the price which seems to be fairly common place with other schemes? would you do just as well going without it? with the grant do you need to remove your gas boiler? one of the options my plumber mentioned was leaving the boiler installed and use it as a backup for the heat if the heatpump for some reason wasnt working or was way out on energy consumption etc.. i won't gain a ton of space back by taking on the gas boiler as the press its in is out of the way and will only free up minimal storage. im thinking ill get him to quote for an install only anyway and see how it adds up. i was sort of hoping as i just need a heatpump and pipework, that the grant might cover most of the cost and id end up maybe having to pay 1500 or 2k on top of it but that seems unlikely from initial quotes

yeah there's no major panic with any of it.. i might see if i can line it up for the spring time..

Agree with championc's comment

"

As crazy as it sounds, you might be better off just replacing the gas boiler, if your current one is nearly knackered, given the current low cost of gas"

A few simple calculations show that an efficient gas boiler is likely to be cheaper to run than a heat pump.

In round numbers, a gas boiler costs 10c. per 1 kWh of heat delivered. To deliver 1 kWh of heat, the heat pump uses only 0.4 kWh ( assuming a COP of 2.5), but if electricity costs 30c. per kWh, then the 0.4 kWh of electricity costs 12c. So using these rough round numbers the heat pump is 20% dearer to run.

Id be hoping to run mostly on stored electricity around 5.5 cents a unit. I know it's not the most financially sensible thing for me to do but I've been interested in doing it for a while.. I like the idea of consistent heat in the house rather than cold to hot cold etc..

Yep pinergy.. if only they did one more hour I'd be laughing.. 3 hours is a little tight to charge batteries, car etc..

It's a good question. I was watching a video where someone was flying a drone in close to freezing in Ireland and it came down with icles on it. They reckoned the dampness in the air in Ireland just makes it that much colder. That they have flown in -20 in Canada and never seen it. Does our inheritant damp winters adversely affect heat pump performance? Compared to colder temps in drier countries?

I have several friends who have got heat pumps installed in the last 4 or 5 years. Their houses are very similar to mine. But their heat pumps seem to be costing much more than our gas heating each year.

We are in a 4 bed detached 180sqm house and have gas heating. Ive been monitoring the gas usage religiously the last 3 years. We use roughly €1400 to €1500 each year. Even weekly it nearly doubles on a week like this week, though there have only been 4 or 5 of those weeks the last few years. My friends with the heat pumps all say the cost of their heating goes up massively on these weeks too.

One got IR heating in his house 3 years ago and got rid of his oil tank and burner. His electricity bill has increased by over €3000 a year now and he has mould in some rooms that arent heated now. The IR heating was a terrible idea. Needless to say he is now looking at a heat pump too, so this question is for him too.

I have smart TRVs in each room controlled by thermostats in each room. Only the thermostats call for heat and the rads are set to stay around 20.5c on the thermostats. Step back to 18.5 overnight. Heating is always on whether we are in the house or not. I might step it back to 18.5 if i remember when we are out, but i forget to do that more often than not. Tried geofencing but there is so much coming and going it doesnt work. I have the flow temperature at 61C on the gas boiler.

Is it economical to go for the grant and get a heat pump? Is it likely to save me any money or should I just keep going as I am. The insulation in the attic is all over the place. Squashed, holes all over the place. Needs to be thrown out and replaced. We have normal internal wall insulation and vents in each room. House built in the mid 90s.

Is there a grant for all of this?

can i ask what your HLI is/was when heatpump was installed? Ours is 1.91.. we don't have external insulation (hollow block construction) but triple glazed windows/doors. and a lot of the house is glazing/doors with insulated attic.. all rads.. in the process of getting heat pump quotes.. so interested to see how it works out.. what supplier / tarrif do you use? we are currently on pinergy 3 hours.. which is great but we can only import abotu 16kw per night.. for nov/dec/jan solar could vary from nothing to max 10kw.. i expect i need to move to a longer tarrif window if we go heatpump so we can get more into the batteries (32kw)

Ours was 1.785 before we installed the mvhr, would expect it to be a bit less now at about 1.55. We had a good airtightness test which also helped.

We are on the Energia EV rate at 0.089c from 2-6am. Pinergy would have worked out slightly better for us but preferred the 4 hour charge window for the EV etc.

On the topic of steel or aluminimium radiators. The output of any radiator is declared in Watts and it doesn't matter whether its steel, aluminium or any other material. E.G. a 500w steel radiator has the same output as a 500w aluminium radiator. The only difference will be the size of the radiator which is very little. Aluminium are three times the price of steel rads and presumably a bigger profit margin for the supplier also which seems to be why they are heavily promoted.

I got 3.45 for space heating yesterday - 21kWh used and 72.4kWh generated

The COP (and running cost !!!) can be excellent or enormous - and hugely dependent on the heat curve - provided the unit wasn't oversized in the first place.

And so many installer still appear to be in the gas/oil boiler mindset - installing heatmizers and any number of 3rd party controls and thermostats, and secondary pumps.

Actuators on UFH manifolds have no place in downstairs or main living areas circuits / loops. They cause stop starts. Same with a heatmizer main controller - designed to stop and start. And 3rd party wall thermostats ….. same.

Set thermostats higher than needed (to act as Limiters only), and control the heatpump output by correctly setting the heat curve / compensation curve (Water Law on Samsung's)