Air Conditioner

Its a heat pump I have which heats my house in winter, they are geared to reduce carbon emissions such are their efficiency. In winter for every 1Kw of electricity I use at the meter the heat pump is delivering 3kw of heat inside the house so Im using approx 66% less electricity than I would be if I had electric panel heaters. So the use of heat pumps reduces carbon emissions by virtue of using electricity in a very efficient manner. These heat pumps are part of the government climate change strategy to wean people off oil & gas to more efficient ways of heating a home.

In summer you can reverse it and the heat pump can deliver proper air con on hot stuffy days. It is not as efficient at cooling as it is at heating but still for every 1kw of electricity used at the meter it is delivering approx 2kw of cool air into the house. I ran it for 30 mins yesterday with a 20c/kwh rate so to cool the ground floor of the house cost approx 5 cents of electricity.

That's wrong. A well insulated house stays warm in winter and cool in summer.

So the plan would be to upgrade insulation and ideally make it airtight (but that might be a challenge).

When you say water source, my understanding was that it was just a heat pump outside that extracts the heat from the air to heat up water which is pump into radiators like a regular oil or gas central heating system. Have I misunderstood?

This is what I did- I replaced 3x 25 year old storage heaters with a single air to air heat pump, it has one unit outside on the wall and another inside providing warm or cool air as needed. Cost was just under 1,900 installed and worth every penny as the storage heaters were need in replacement anyway. My electricity bill went down a fair bit after installation, a direct comparison was a bill of 252 for Oct/Nov before installation and then the following Oct/Nov the electricity bill was 145.

But as Sleeper said the insulation of the house is important before installing any heat pump. They are remarkably efficient at providing heat but if your house is badly insulated and has draughts then they have to work extra hard to produce the same heat and they can actually turn out very inefficient and expensive to run.

Maybe crossed wires, I am talking of air to water heat pumps, which are air source but use the heat to heat up water which is then pumped to radiators to heat them similar to a GFCH. It doesn't get as hot hence the need for good insulation.

Having both systems is interesting. Do you have your gas zoned or do you just turn off the radiators?

This is very interesting, How do you find the hot air for heat as opposed to traditional radiators? €1,900 seems very reasonable for this. Do you live in an apartment or a house?

I've turned off any apartment that is based on storage heating as I figured I couldn't replace it because of the rules about drilling through external walls.

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.

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.

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.

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.

This is the one we got.

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.

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.

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

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...

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!

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.

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?

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

Except that the Irish heat pumps are regularly attached to radiators; not as efficient a method of achieving cooling.

He's a good guy.

Next step would be to find out who supplies that make in Ireland. They should have service engineers for covering the warranty period. I know yours is out of warranty but same engineers can repair the unit out of warranty