Heat pumps for hot water

Asdfgh2020

Looking for peoples experiences/views on the the above……270 litre tank sounds great but what are the running costs…..are they that much better than traditional immersion / indirectly heated copper cylinder…..the one in link below sells for €2600 approx……?

https://www.heiz24.de/Hot-water-heat-pump-Atlantic-Explorer-Evo-2-WT-cylinder-270-litres-1-heat-exchanger-New?curr=EUR&gclid=CjwKCAjwqauVBhBGEiwAXOepkZTRKSPVEnCPHbHtGwBEmHpFD3Tyr9oChYWnaIWzAWwupkoP1UIFRRoCYJoQAvD_BwE

John.G

You might possibly get say a COP of ~ 3.0 ("300% efficiency") overall if you only heat to 45C with one weekly increase to 60C for legionella protection. I am paying ~ 30c/kwh for Elect just now so if all the water is been heated at full cost then 30C/kwh or ~ 15C/kwh for night rate, effectively becomes 10C/kwh & 5C/kwh. I paid 140C/liter for oil, last fill in March. If you allow ~ 70% boiler efficiency on HW heating only, then the cost becomes 19.4C/kwh, you might want to factor in cost of replacement unit/compressor every 8 years or so and while a gas/oil boiler might be somewhat similar (but every 10/15 years) you are also running the CH off this so probably shouldn't factor the boiler replacement cost?.

Asdfgh2020

https://www.boards.ie/discussion/comment/119218601#Comment_119218601

So to summarise……..you are saying (as is the norm with these type of ma-sheens) there isn’t a lot to be saved and there is a massive Payback time…?

John.G

If you assume DHW requirements at 200LPD at 45C (from cold water at average temp of 10C) then energy requirement is 8.14kwh + say 1.5kwh/day for cylinder losses, total, 9.64kw/day or 3519kwh/year. Heat pump cost €352 or €176. Oil cost €603, simple pay back time, 2600/(603-352), 10.4years or 2600/(603-176), 6.1 years.

Asdfgh2020

https://www.boards.ie/discussion/comment/119222236#Comment_119222236

What do you mean by €352 or €176. Is that day rate v night rate…?

also what would be comparison with using electric only as in immersion element……I would Think vastly better…?

John.G

First point, yes, day vs night rate.

Normal electric immersion will cost you 30C or 15C per kwh, so day rate cost, €1056/year, night rate €528/year.

Borzoi

My thoughts would be:

A 5 year warranty is useless, if there's no one in Ireland who can (is prepared to) service / repair them.

its an exhaust air heat pump, so it takes heat from the surroundings and then dumps cold air to outside using a short duct. so it should be on an external wall, or near one. and you have to factor the costs of heating the air that is is using as a warm air source into any calculations

asdfg87

https://www.boards.ie/discussion/2058250575/heat-pumps-for-hot-water

Hi Brother,

I think the key to this is if you put 1.8 kw in what do you get out, ie what amount of kw is picked up from outside eviornment.

An experienced plumber told me recently that air to air heat pumps for heat increase by factor of 3.

If the pump is 1kw it will give 3kw of heat to the room.

Asdfgh2020

https://www.boards.ie/discussion/comment/119222440#Comment_119222440

Brother……? I take it you are basing this pseudo familiarity on the similarity of our user names…..?

In any case I don’t quite get your point….I’m purely talking about a heat pump to heat water only……not spaces…?

Asdfgh2020

Bumping this thread……does anyone know if there are grants available from SEAI for these ‘air to water’ water only type units….?

snowcat

https://www.boards.ie/discussion/comment/119222448#Comment_119222448

I have one of these powering 6 showers for 8 people. About 3kw a day to power it. Very cheap to run. Long term reliability I cant comment on. Have it 18months so far.

Asdfgh2020

Were you able to get any grant towards its cost…? I’m seriously considering getting one installed……4 showers for house of 7 people.?

snowcat

https://www.boards.ie/discussion/comment/119629557#Comment_119629557

I put it in as part of a new build. It can be used instead of solar panels. I dont know about the grant. I have a second one recently installed in another house. About 2100 with a coil. Without a coil they are a good bit cheaper i think about 1600. I have 6 showers in one house and 7 in the other.

Asdfgh2020

W

https://www.boards.ie/discussion/comment/119629594#Comment_119629594

Thanks for responses……especially given it’s a Saturday am….😀 I’m just about to start my ‘Childrens activity sat am pick drop multiple times routine’ so only time for one last question…..what make and model did ya install and what part of the country are you in….pm me if ya don’t want to reveal where ya are…!

snowcat

https://www.boards.ie/discussion/comment/119629629#Comment_119629629

I installed the Atlantic one. 270litres with a coil.

Jinglejangle69

https://www.boards.ie/discussion/comment/119222236#Comment_119222236

And your heat pump will be busy after around 8 years.

Meaning you will have no payback as you will have to buy a new one.

They are a con job, not fit for Irish weather.

thugtomas

Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly.

10-10-20

https://www.boards.ie/discussion/comment/119629662#Comment_119629662

? 8:48 might be a bit early for you.

So they are fit for what 'weather' then? If it's German 'weather' that they are fit for, consider that Germany have a lower average Winter temperature than us, so please enlighten us further.

snowcat

https://www.boards.ie/discussion/comment/119629799#Comment_119629799

Considering a standard 270litre cylinder would be around 1000 the cost of the heat pump part is about 1100. Im saving around 50 euro a month on electricity so payback over 2 yearsfor me.

John.G

Is that saving based against oil or gas or electric immersion cylinder heating?.

10-10-20

https://www.boards.ie/discussion/comment/119630058#Comment_119630058

I was rather directing my ire at Jinglejangle69.

Even though I'm using gas to heat my water, I'd probably have pretty good savings as my boiler is ~25m from the hot-tank. The losses there are going to be large enough.

What I especially like about these devices is how they can become part of the ventilation system within the house, tapping the outgoing feed for warmth with better efficiency than a plate heat-exchanger.

Asdfgh2020

https://www.boards.ie/discussion/comment/119629662#Comment_119629662

Can you elaborate a bit further please before I go further with this……how do I know you are just not a troll working for an alternative product…..?

snowcat

https://www.boards.ie/discussion/comment/119630093#Comment_119630093

Basing it on 7 electric showers at 10mins once a day. Im approxing 10kw electric shower @ 20cent a Kwh

deezell

Just to call bullsh*t on some of the figures touted on this thread, particularly the one that compares the cost per kwh of heat from a heatpump, compared to oil, and has the heatpump at just over half. Its claimed the kwh cost of the heat pump HW is 10 cent/kwh. This must be based on the fantasy 4 to 1 return per kwh of the heatpump, and 40c per unit for the electricity.

It's then claimed oil will cost 71% more, about 17cent/kwh. Last time I looked a litre of kerosene had an energy output of 10.35kwh per litre. Having just paid 1.13 for a litre, and with a highly efficient 93% condenser boiler (especially if I only allowed flow to heat to a measly 45°), I make that about 12c/kwh. In cold weather you will struggle to get a COP of over 2 on your heat pump. If you're paying 50c/kwh for your daytime rate, as punishment for cheaper night rate, then your heatpump HW is costing 25c/kwh. Double, not half of your oil boiler. Add the massive installation and depreciation costs of heat pumps, its a waste of money.

Biggest joke, the electricity you are consuming in this heatpump is currently close to 90% generated by burning mostly gas, but also oil. 55% of the gas heat and 62% of the oil heat is lost in the generation process, and a further 5% of whats left is lost over the transmission lines to your home. So much for lower carbon ar&e print. Its nonsense to ban burning gas ( or oil) directly in your home in a cheap efficient burner which can be installed for as little as a grand for gas. The eco bull continues to be peddled though. We are so far away from independence from fossil fuels, we should just face reality. Pour all the grant money into insulation and passive homes, and burn the tiny amounts of gas needed in them.

Be not afraid

https://www.boards.ie/discussion/comment/119996524#Comment_119996524

Great practical points deezell on how the costs really hit your pocket. And to add, the jury is still out that increasing carbon dioxide is a negative to our planet. Repeating a lie, a million times doesn't make it true, but it might make one richer and admired (or prevent one from getting fired or shunned) in the near-term if you're a scientist, in education, or in media, because one is going along with the narrative that is the flavour of the month at the moment, kind of like the earth being flat or when slavery was acceptable in a previous time. Google "How to Think About Climate Change | William Happer"

"It's easier to deceive people than to convince them that they've been deceived."

Asdfgh2020

https://www.boards.ie/discussion/comment/121307513#Comment_121307513

Thanks for bumping this thread. We still haven’t done the ‘heating upgrade’ and most likely will leave it until the spring now. From reading through this Thread again and in particular the post above from deezell, it looks like I’d be mad to go for the air to water water heater….I’ll stick to what we have ie. New more efficient oil boiler that is convertible to HVO and improve insulation.