Air conditioner or air source heat pump?

[MrSniff]

Hi, I've been a bit of a lurker on this fantastic site, happily soaking up information and tips. I'm not a self-builder (yet - it is certainly a dream to one day take the plunge), but a DIY maintainer and updater of a couple of houses.

 

We recently bought a house here in Luxembourg (built in 2009 out of plenty of concrete and the most solid blocks I have ever come across). The main heating is UFH, heated by a district hot water station, the controls for which will be the subject of a separate post...

 

The house also has three wall-mounted Haier air conditioning units, each with its own external unit. One has never worked, not showing the slightest interest in life. The other two work (although one of them only after swapping the capacitor from the dead'un) - until now, when a second has died whilst in heater mode: the louvres remain open, so not a controlled shutdown. I have checked the obvious: electrical supply, connections as well the fuse located on the control circuit board which seems purposefully designed to be dropped into the guts of the machine. When we bought the house, the sellers said they had never used the AC units, so that is at least 5 years of disuse.

 

So, a couple of questions.

• The first is sort of in the title: is an AC unit an ASHP which I should be able to use for supplementary heating, or is it likely the heating was supplied by some sort of element which burned out causing the unit to fail?
• Is there anything else I should check - any fuses I haven't found in the external unit?
• I plan to replace all the motor capacitors, is there anything specific I should look for? I think it should simply be a straight swap of a new 450VAC 25μF polypropylene capacitor, but is there any other specs I should be looking for?

 

Any thoughts would be very much appreciated.

 

 

[Onoff]

Welcome. Make sure the capacitors are motor rated.

[scottishjohn]

ASHP is nothing like an air con unit

it runs on electric 

I suppose it depends how cheap you get your hot water from distict heating system .

It needs to be outside the building and does make some noise,less than air con unit so position from neighbours needs to be though about

 

[Gone West]

There are different types of ASHP and an AC is an air to air ASHP. A2A HPs can provide cold air only or warm and cold air.

[Jeremy Harris]

On 12/01/2019 at 14:44, scottishjohn said:

ASHP is nothing like an air con unit

it runs on electric 

 

 

FWIW, the core components of an air con unit and an ASHP are identical, and many units can be run both ways quite happily.  The only difference  is that a heat and cool unit will have a 4 way reversing valve, a heat-only unit will also have a 4 way reversing valve, but a cool-only unit may or may not have a 4 way reversing valve; it depends on whether or not the manufacturer just uses a generic refrigerant circuit for several models in their range.

 

We've been running our ASHP in both heating and cooling mode pretty much since the day I installed it.  Cooling mode wasn't advertised as being available by the UK company that badge engineered it, but was there in the control system and just needed to be set up to enable it to work.

[scottishjohn]

5 hours ago, JSHarris said:

 

FWIW, the core components of an air con unit and an ASHP are identical, and many units can be run both ways quite happily.  The only difference  is that a heat and cool unit will have a 4 way reversing valve, a heat-only unit will also have a 4 way reversing valve, but a cool-only unit may or may not have a 4 way reversing valve; it depends on whether or not the manufacturer just uses a generic refrigerant circuit for several models in their range.

 

We've been running our ASHP in both heating and cooling mode pretty much since the day I installed it.  Cooling mode wasn't advertised as being available by the UK company that badge engineered it, but was there in the control system and just needed to be set up to enable it to work.

don,t confuse  the non techie people ,not as though hes going to make one is it?

 

[Jeremy Harris]

14 minutes ago, scottishjohn said:

don,t confuse  the non techie people ,not as though hes going to make one is it?

 

 

 

Sod all to do with making one, just about knowing how they work so that one that does heating and cooling can be chosen.  Not rocket science, just a matter of reading the specs and understanding that the manufacturers of ASHPs often hide the fact that they will cool just as well as they heat, perhaps because to be eligible for the RHI the cooling functionality has to be hidden, even though it's always there for a heating ASHP.

[newhome]

34 minutes ago, scottishjohn said:

don,t confuse  the non techie people ,not as though hes going to make one is it?

 

 

I’m never ever going to make one but I do like to know how things work in theory at least and @PeterW had already explained to me how similar it was to an air conditioner  which didn’t require any technical knowledge on my part at all TBH. Even having a basic knowledge of how something is supposed to work prevents being done over when someone comes to service it or whatever. 

[MrSniff]

Thanks for the responses. The units do have cooling and heating settings, and I couldn't see a heating element so it's helpful to understand that although not installed as an ASHP, it provides A2A heating in the same way. With that understanding I can at least have a bash at looking for obvious reasons why it stopped, and as a next step have an informed discussion with an engineer (not so easy despite the fact that most here speak English to varying levels). Since there is so much buildings going on in Luxembourg paying far better than individual customers, getting a decent tradesman in the first place is challenging. With that in mind, given that the fuses are intact and that at least one of the motor capacitors in the compressor units has failed (proven by switching) and I can see no other obvious sources of failure, I will replace them with new as a first step...