Air Conditioner

Sleeper12

An air pump is the least efficient of the 3 types of heat pumps because they become very inefficient at 5C or below. The ground & under water is warmer than the air when the air is 5C or below. At 5C or below a bog standard gas boiler is cheaper to run than an air pump.

Air to water works far better with underfloor heating compared to using it to heat rads as it only heats the water to around 30 degrees compared to 65 degrees using gas or oil. To use it for central heating then you'd be looking at spending close to 40k on an older house to bring it up to standard. You won't save this in your lifetime. Apart from spending all this money on airtightness you'd need to double the size of any rads. Water only reaching half of the temperatures or gas /oil means needing to double the size of the rads.

This type of setup is only viable on a new build imo. But then on a new build you would go for ground or water source. You'd be mad to go air (least efficient) on a new build when you'd have ground diggers & the likes on site anyway.

Any idea of the BER rating of the building you are looking at? Or the age of it?

Muahahaha

https://boards.ie/discussion/comment/117627950#Comment_117627950

Mine is in a house so just on the ground floor kitchen-living room which is open plan. I still have regular panel heaters in the bedrooms upstairs. And yeah the price was very reasonable, it probably would have cost me not too far off it to replace the 3 knackered storage heaters with 3 new ones. Both units are Mitsubishi so hopefully they will last for years to come.

I havent lived with radiators for over 20 years so cant really compare. I have always had storage heaters in rented accommodation and I often found the air from them very dry, sometime visitors would say it effects their throat. The hot air from the heat pump is dry but not as dry as storage heaters in my experience. Its never bothered me anyway but it might for some people with sensitive throats.

Regarding apartments yes the outside wall is owned by the management company so you cant drill pipes through it to place the heat pump on the balcony. However I do know people are doing this as my installer was telling me about it. A lot of storage heaters in apartments are getting to 20+ years of age and some people in apartments are replacing them with air to air heat pumps. It could cause the trouble down the line with the management company but I suppose it depends how exposed the balcony is to outside eyes, some balcones are very private and it wouldnt be possible to see it so I guess some people are willing to take a risk.

ercork

https://boards.ie/discussion/comment/117626918#Comment_117626918

An air to air heat pump would certainly be better than storage heaters. For every unit of electricity you use, storage heaters give you one unit of heat - a heat pump will give you 3 or 4 units. Storage heaters do make use of half price night rate electricity but even at that, the heat pump would definitely beat them. If the house is not too big, then the single indoor unit as described by the poster above will probably suffice. That might depend on the layout of your house though - if the downstairs is mostly open plan you'll be fine.

Fitting an air to water system would cost a lot more - both the unit itself and the fact that you will have to retrofit radiators or underfloor heating throughout the house. But, it would provide hot water which an air to air system will not.

JimmyVik

So glad of the aircon both in the car and in the house this last week.

Maybe get two weeks use of the one in the house and then switch it off for another year :), but it is nice at the moment.

Sleeper12

https://boards.ie/discussion/comment/117633094#Comment_117633094

I agree air to air would be better than storage heaters. Just wanted to point out that air to air doesn't always give 3 to 4 KW for every 1KW it uses. This is it's best possible performance. It all depends on the outside temperature. Colder it is outside the harder it has to work. When temperature drops enough then storage heating would work out cheaper because of night saver rate. I'd rather pay a little extra though & not have storage heating

ercork

https://boards.ie/discussion/comment/117640067#Comment_117640067

You're definitely right that water and ground sourced heat pumps are a better job given that water and earth hold their heat a lot better than the air does. But the significant capital cost of installing them as well as the fact that most people do not have access to a water body on their property makes them unrealistic for the majority of people.

Regarding air sourced hps, many manufacturers claim to have overcome the problem with them struggling below 5C. My own one claims to maintain the efficiency down to -10C.

Sleeper12

https://boards.ie/discussion/comment/117645491#Comment_117645491

Oh you can get air pumps that work perfectly at very low temperature. They come with a defrost mode. The real issue is that air heat pumps are very expensive to run below 5c. Not too bad in new air tight homes but in regular homes you still require gas or oil for colder days to keep your heating bills low

JimmyVik

https://boards.ie/discussion/comment/117645935#Comment_117645935

We have one that heats a 50sqm room on the North side of a house with no direct sunlight on it up to about May.

January was more expensive than December to heat it, and was the most expensive month.

On its consumption meter for example in January this year it used an average of about 7.5 units of electricity per day.

In Feb the average dropped to about 5 units per day, same hours.

That was coming on at 6am and off at 9pm.

The last two weeks its been an average of about 2 units per day to cool to 20C from about 8am until 8pm.

Here are the averages for the last year

Jun 0

May 1.5

Apr 3.75

Mar 4.75

Feb 5

Jan 7.5

Dec 7

Nov 4

Oct 2.25

Sep 0.25

Aug 1 - Cooling

Jul 1.5 - Cooling

It was €900 fully installed (two 6 inch holes and a half inch hole through an outside wall). Then just plug it into a normal socket. It has an app and can be set and controlled over the web from your phone. You can hear it struggling (fans going full blast) when the outside temp is less than about 4C, but it still keeps the room at 20C even when it was below zero outside. You can get ones with an electric heater in them to help them too for an extra €200, but we didnt bother with than one. Ours is purely air to air.

Now thats a big room that its in and you would need one in each room if you used the type i have if you wanted to heat the whole house (BER E, but we put in attic insulation and pumped the cavities but havent got a new BER yet).

But smaller rooms would cost significantly less to heat also. At the moment have panel rads in the other rooms controlled by individually controlled by automated thermostats, but thinking of getting air to airs in them maybe too.

I guess you get get one big air to air and duct it, but that might be an expensive job.

The one we have would do a whole apartment i think though if you left the doors open in the bedrooms.

Sleeper12

https://boards.ie/discussion/comment/117646200#Comment_117646200

You might want to get an electrician in to check that out. Pretty sure they require their own dedicated cable going back to the fuse box & a dedicated RCBO. I'm a plumber and not an electrician but I have never seen a heatpump plugged into a regular socket before. Usually the outside unit has an electrical shutoff within a few foot of it. Might be a good idea to ask on the electrical forum here. They will be able to tell you what the regulations state.

noplacehere

https://boards.ie/discussion/comment/117646200#Comment_117646200

Would you mind sharing more information about the original cost/install? How do you know what model etc?

JimmyVik

https://boards.ie/discussion/comment/117646419#Comment_117646419

It come with a 3 pin plug on it. Its fine.

JimmyVik

https://boards.ie/discussion/comment/117646531#Comment_117646531

This is the one we got.

https://www.nationalheatershops.co.uk/product/powrmatic-vision-3-1-dw-air-conditioner/

https://www.kdsupplies.co.uk/products/powrmatic-vision-3-1-dw-unit

Ignore the prices. I saw the same model for anything up to €4500 without even installation.

Contacted a builder I know and he sourced one for €900 and fitted it in an hour.

That was about 3 years or so ago. Pretty sure you can get much better ones now too.

This one is all inside with only the air goin outside.You can also get ones with a big outside unit instead of having the heat exchanger in the inside unit.

If I was going for another one id probably go that way, just because the inside unit would be much smaller.

I actually saw someone post what looked like the exact same one but with different branding on boards last year for about €750.

ercork

https://boards.ie/discussion/comment/117646419#Comment_117646419

For the air to airs, the power consumption is about 1kW so no need for a dedicated line to the fuseboard. Air to water units are a bit more power hungry - they would have the direct line and the direct shut off switch alright.

ercork

https://boards.ie/discussion/comment/117646829#Comment_117646829

These air to air units are a very tidy solution - no bulky fan unit on the outside wall, just two discreet holes. They would probably be a good fit for apartment buildings where the management company may not allow a unit to be installed on the external wall.

The main downside of them is their low(ish) efficiency. The brochure on that website quotes a COP of about 3 whereas the better quality split units can be as high as 5. On the other hand, the split units require a fully qualified refrigeration engineer to install so are a bit more costly in the beginning.

JimmyVik

https://boards.ie/discussion/comment/117649023#Comment_117649023

I find that unit is grand for a 50SQM room. If I was going with one for a normal sized room i would go for the smaller one though.

No point oversizing for the amount of heat it is required to give. Just wasting money on it. Plus you need one for each room you want to heat, unless you leave the doors open.

They are very noisy on the outside though. If you had a load of them in an apartment building, the outside might sound like an airport :)

Quiet enough inside though.

Markcheese

Anyone ever tried the American style window units ? Are they even available over here ?

Euphoriasean

Has any added an AC unit to their existing Air to water system. Have an exiting air to water system but interested in added air con. Have underfloor downstair with rads upstairs. Any idea of approx cost & what would build work would be required?

Strumms

With these summer temps as they have been this summer and the overall effects of climate change that will, are and can be felt and will always be I think you’ll see even more calls for information for AC installation advice... won't be getting it this year at home but I think next year I’ll bite the bullet post the covid shîtshow...maybe February / March and get set....it’s a newish build as in less then 10 years where I am,, the insulation is absolutely incredible in the winter, but the downside of that is if the temps in the summer are as they are now it becomes absolutely like an indoor Sahara. Once 24/25 degrees plus you need every single window and back door open wide...for a good duration at least...

im liking the idea of getting four units installed at home....one in both bedrooms, one in kitchen / dining area and one in the living room...

be interested to hear of anybody who has gotten or is getting aircon systems, reviews, thoughts, prices etc...cooking earlier and I’ve never know heat here like it I just wolfed down the food to get out of there.... weird... anyway what I like please is any experience positive or negative of getting systems installed...including prices, thanks...

vickers209

https://www.boards.ie/discussion/comment/117650737#Comment_117650737

Intrested to know this also i have a mitsubishi ecodan r32 air to water heat pump used to heat rads up and downstairs

not even sure if this can be used for cooling but would like to know costs involved

FGR

https://www.boards.ie/discussion/comment/117658409#Comment_117658409

Have an air to water heat pump that heats rads downstairs. Would like to know if this option is available for my dimplex unit before I go and get a seperate system installed altogether.

I vowed during the heatwave a few years back that I wouldn't be caught out again. And of course I got caught out!

Euphoriasean

https://www.boards.ie/discussion/comment/117660226#Comment_117660226

I'm presuming this would require significant ducting which would end this option for me. Wish I thought of this when the house was being built a couple of years ago.

Cuddlesworth

https://www.boards.ie/discussion/comment/117661964#Comment_117661964

If its new and has good insulation, you would probably find some external shutters would do wonders for temps in the house over air-con.

Euphoriasean

https://www.boards.ie/discussion/comment/117662353#Comment_117662353

Would certainly help, but for the limited days per years that this would be required, I don't think I'd change the external image of the the property. Now that the rains back, I'm sure I won't think of this again until we get out next heatwave whenever that will be.

ercork

I don't know if it's possible to retrofit a/c to an existing a2w system but my guess is that it isn't. Most a2w systems are monoblocs where all the refrigerant components are housed in the outdoor fan unit. To add a/c an engineer would need to open up the unit and run some additional refrigerant lines from it to each room in the house where a/c is required. Monoblocs are not designed to work that way.

Even if it is possible and feasible, I assume if you use it for cooling you can't get hot water for showers at the same time?

Cuddlesworth

Air to water, with water being on the inside through radiators? In theory, its possible. But the thermal mass of the water combined with the hot water tank would be difficult to do.

Nermal

https://www.boards.ie/discussion/comment/117622618#Comment_117622618

It isn't.

This thread is Jevon's paradox in action.

Energy efficiency gained by installing heat pumps is not 'saved', it's just consumed elsewhere.

kozak

Hello

Couple of comments in this thread mentioned Powrmatic Vision 3.1 air to air heat pump. Any advice what company or engineer can service and fix those in Dublin? Mine was installed in 2017 (apartment in Dublin 18). Heating works fine, cooling in summer very inefficient, take ages to cool 18sqm bedroom. Original installer assured everything is fine, did servicing for 3 years, now gone.

Thanks

Sleeper12

https://www.boards.ie/discussion/comment/121825074#Comment_121825074

I'd imagine it's undersized for the room or else the coolant needs topping up / recharging. He would have topped it up as part of the service so possibly the unit is undersized

NSAman

https://www.boards.ie/discussion/comment/117048431#Comment_117048431

That’s not always the case. Our apartment can be stiflingly hot in summer, air con will be installed this year. Our holiday home already has air con, it allows for heating, cooling and dehumidifying a very valuable addition to our home.

kozak

https://www.boards.ie/discussion/comment/121825102#Comment_121825102

One of comments in this thread mentions the same model being sufficient for 50sqm room. It's 3kW unit so should be ok for 18sqm. Coolant is more likely reason - so back to my question - any advice who can do maintenance of such unit in Dublin, say coolant top-up?