Which ASHP are set up to cool

[DanT]

3 hours ago, Bob77 said:

Yes I’d definitely be interested in that. Sounds like a cheaper option than going for separate AC. 

Not sure if this link will work but this is where I got it. They wouldn’t ship to the UK when I bought it last year so we had it sent to a colleague in Ireland. Daikin part number for ours is EKHBCONV. This was for 6Kw split
 

https://www.gus-astuces.com/pompe-a-chaleur-moyenne-temperature-daikin/702-kit-rafraichissement-daikin-altherma-3.html

[RussMac81]

Hi everyone

 

Thanks for all the helpful stuff above, it was a god send to find the cheap coding resistor trick 😊

 

I’ve done a lot of research regarding cooling with Vaillant Arotherm Plus which I thought helpful to share – not least because any critique would be helpful too.

Also really interested in how the fan coil mentioned above worked out for people.

 

We live in a classicly problematic modern house – loads of insulation, loads of glass and all south facing.  Cooks even on spring and autumn sunny days.  Like many, we want to cool 4-5 bedrooms.  Not fussed about downstairs.  Got the 10kw or so cooling capacity out the Vaillant and reluctance to have another outdoor unit and all the faff that entails.  Having spoken to various air source and air con people we’ve decided to go down the fan coil route.  Advantages being that we can just run a dedicated cooling water supply from buffer tank to the fan coil in loft which I can insulation to high standard and then not have to worry about dew point and condensation issues as you would with rads and underfloor.  We’re lucky in having a service space directly from boiler room to loft (from oil boiler / flue days).  Also the fact that it’s much easier to get the 10kw out quickly via  fan coil than it is through the underfloor or rads given limited temperature deltas, although I've spoken to others who have had a good experience with rads and the axial fans you can attach to them (there are even hidden ones) which effectively turn them into a fan coil.

 

You can get fairly cheap ducted fan coil units (i.e. water rather than refigerant based) to go in a loft space (hung on straps from rafters for noise insulation) from where I understand simple 200mm flexi ducts would be OK for each room.  The more sophisticated fan coils can vary fan speed/flow rate by room (google for multiroom by Ability as an example).  You could have a single exhaust centrally in hall but you’d get less control and might confuse the system as it’ll be permanently pulling hot air up from downstairs, plus we want to control by room so we’re going to run an exhaust from each room.

 

Anyway, the aircon guys I spoke to said not to be put off by the various assertions that everything needs to be calculated and what not and that in general terms:

• 200mm flexi duct in and out of each room, opposite corners would be fine.  Simple diffuser on end of each flexi. 
• Insulate cold ducting (no need to do that for exhaust)
• Aim for 28-30 cu m / min flow on high fan, with high static pressure, and with filter included
• Air going into room aim for 10-12 degrees
• About 2-2.5kw per bedroom normally fine

We plan to go one step further and put simple duct actuators on each room if we can’t get the better fan coil with individual room control.  Also, given that often our house overheats on days where it is perfectly cool overnight (but hard to exchange air into room given high ceilings etc), we’ll have a fresh air setup that doesn’t run cooling water and simply pulls air in from outside into the rooms.

 

Because there shouldn't be the big lag issues others have experienced via UFH/slab, I'm figuring that a fairly simple zone control setup will work fine.

 

Anyway, all theory thus far as we haven’t started the install.  Interested in any feedback in case any of this is wrong, and I can follow up here once we know how it performs (likely now next summer tho!).

[joth]

This sounds reasonable and like you're on a good track. Surprised you've found Aircon installers familiar with doing FCUs from wet ashp but it's only going to become more popular with time.

 

Where are you finding the supplier for FCU?

 

16 minutes ago, RussMac81 said:

We plan to go one step further and put simple duct actuators on each room if we can’t get the better fan coil with individual room control. 

 

Not quite clear if you're talking one single big FCU splitting ducts via electric baffles into each room, or one FCU per room. The latter gives finer control per room, the former maybe cheaper, needs less condensate drains, but limits your options around duct routing as everything needs to come from a single central source.

I'm doing a mix (2 FCUs each serving 2 rooms).

I got cheap electronic 200mm duct baffles from AliExpress.

 

19 minutes ago, RussMac81 said:

Also, given that often our house overheats on days where it is perfectly cool overnight (but hard to exchange air into room given high ceilings etc), we’ll have a fresh air setup that doesn’t run cooling water and simply pulls air in from outside into the rooms.

 

Do you have a plan how to pull in this air from outside?

Do you have MVHR? The extra penetration for this new air intake may unbalance it, and also it annoys me to think of bringing in extra cold air from outside during heating season. Otherwise I'd have done this too. (We almost installed a skylight in the loft space specifically for this use case 

 

Keep us updated!

 

[RussMac81]

@joth   FCU I am thinking of using is from Agility.  It has 4 outputs each individually controlled.  £1600 so not really much different in cost to buying one FCU per room, though has a commissioning charge on top.

 

No MVHR.  I don't need to worry on fresh air as I'm only doing it when we consciously want to bring in cool evening air to get rooms down in temperature without having to pay to run the ASHP.  In winter ASHP will be via underfloor and rads, so FCUs not running.

[RussMac81]

PS:  regarding the question on source of fresh air, our old decommissioned oil boiler (before ASHP) had a flue going out roof which is still there.  Although flue only 100mm looks like its encased in a second duct so whole thing 200mm which may be enough for my fresh air to avoid a further roof penetration.  If not I'll have to core drill a gable wall which I'd rather avoid.

 

[J13USH]

I am having a Samsung Joule 16kw ASHP installed in my house. Has anyone set this ASHP up (or a similar one) to do underfloor cooling? 

 

If so how did you do it?

 

Samsung have said the UK models don't have this function but I suspect they are just trying to cover their backs. 

 

The spec says 14kw cooling so I am not sure what that would mean if they don't do cooling.

[JohnMo]

I would get a full set of manuals, down load them for the heat pump - not the Joule one. Then get reading, it should be reasonably straight forward.

 

There will be something it looks for to enable cooling, mine not the same as yours, has a switch contact that changes it from heat to cool. You will/may also need a thermostat suitable for cooling, unless you does that.

[Blooda]

@m0deller  Sorry to resurrect an old thread, how is the cooling with the Vaillant ASHP turning out?  Have you altered the settings since last year.

 

Thinking of splashing out the fiver for the 0020266328 plug.

 

Thanks 

[JamesPa]

21 minutes ago, Blooda said:

@m0deller  Sorry to resurrect an old thread, how is the cooling with the Vaillant ASHP turning out?  Have you altered the settings since last year.

 

Thinking of splashing out the fiver for the 0020266328 plug.

 

Thanks 

That's come down in price, was £200 a year ago.

 

I guess Vaillant realised that selling a resistor for £200 wasn't sustainable.

[Dan F]

22 minutes ago, JamesPa said:

That's come down in price, was £200 a year ago.

 

I guess Vaillant realised that selling a resistor for £200 wasn't sustainable.

 

No, I think they still sell it for that, or more.  You need to get the boiler one and not the ASHP one 🙂

[Dan F]

46 minutes ago, Blooda said:

@m0deller  Sorry to resurrect an old thread, how is the cooling with the Vaillant ASHP turning out?  Have you altered the settings since last year.

 

Thinking of splashing out the fiver for the 0020266328 plug.

 

Thanks 

 

Works really well here with UFH.  Do you also have UFH or other emitters?

 

The only issue with Vaillant and cooling UFH is controls. I just posted about this a couple of days ago and the thread has other people's experiences too:

 

 

[Blooda]

We have UFH with Rad's and Towel Rails upstairs.  But would probably run it manually. 

 

I have ordered the resister and will probably fit it by the time it snows.

 

 

[DanDee]

1 hour ago, JamesPa said:

That's come down in price, was £200 a year ago.

 

I guess Vaillant realised that selling a resistor for £200 wasn't sustainable.

Edited September 7, 2023 by DanDee

[m0deller]

2 hours ago, Blooda said:

@m0deller  Sorry to resurrect an old thread, how is the cooling with the Vaillant ASHP turning out?  Have you altered the settings since last year.

 

Thinking of splashing out the fiver for the 0020266328 plug.

 

Thanks 

Have had cooling running for the last few days, just downstairs using UFH. It does help. It's not as effective as A2A AC , but for £5 it's worth it. 

I am also exploring using fans on rads for upstairs. It drops the temp down a few degrees. 

[JamesPa]

3 hours ago, Dan F said:

 

No, I think they still sell it for that, or more.  You need to get the boiler one and not the ASHP one 🙂

Are they the same then?  And how does a boiler do cooling, or is the boiler one for some other purpose but in fact the same part?

Edited September 7, 2023 by JamesPa

[Dan F]

13 minutes ago, JamesPa said:

Are they the same then?  And how does a boiler do cooling, or is the boiler one for some other purpose but in fact the same part?

With boilers they are used to select the type of gas e.g. propane/butane etc., but the same thing.  It's what they call a "coding plug" or "coding resistor" I think.  You'll find more details if you go back up through this thread.

[JohnMo]

21 minutes ago, JamesPa said:

Are they the same then?  And how does a boiler do cooling?

On a gas boiler its a resister for natural gas to lpg conversion. At the beginning of the thread it mentions it

 

Repeat of the above h too slow doing the response 

Edited September 7, 2023 by JohnMo

[JamesPa]

3 hours ago, Dan F said:

With boilers they are used to select the type of gas e.g. propane/butane etc., but the same thing.  It's what they call a "coding plug" or "coding resistor" I think.  You'll find more details if you go back up through this thread.

 

3 hours ago, JohnMo said:

On a gas boiler its a resister for natural gas to lpg conversion. At the beginning of the thread it mentions it

 

Repeat of the above h too slow doing the response 

I found it back up the thread, its a useful tip thanks.  I will (a) use it myself and (b) pass it on.  

 

Unfortunately the practice of selling 'upgrades' when there is no actual change in the hardware or software (other than the contents of a register) has been established for decades.  I did a bit of work with ICL in the 1980s/early 1990s (remember them, the Manchester based British mainframe company, eventually bought by Fujitsu), I was told that several of their models could be 'upgraded' with a software 'switch'.  So you didn't even get a nattily packaged resistor for your money!

[JohnMo]

6 minutes ago, JamesPa said:

the practice of selling 'upgrades' when there is no actual change in the hardware or software

Is just a con, even more so when you just change a part number, and upsell a £5 item (which cost pennies to make) for several hundreds.

 

Puts you off the brand altogether.

[Dan F]

54 minutes ago, JohnMo said:

Is just a con, even more so when you just change a part number, and upsell a £5 item (which cost pennies to make) for several hundreds.

 

Puts you off the brand altogether.

 

Agree! My social media following is non-existent, but be good for someone to call them out on it.

 

Mine came as part of my initial insulation, and the part list wasn't itemized in the quote. So, I'm pretty sure I would have paid full price for it 😞

[Blooda]

On 07/09/2023 at 12:53, Blooda said:

We have UFH with Rad's and Towel Rails upstairs.  But would probably run it manually. 

 

I have ordered the resister and will probably fit it by the time it snows.

 

 

So the part is fitted. and sensocomfort lets me set up cooling. and for a period of time.  

 

The rad's upstairs have TRV's so these will need to be set at 5.  

UFH has 3rd party Emmeti Eletrothermic actuators on the manifold, normally closed.  so just wondering the best way to get control of them ? 

 

 

 

[JohnMo]

You either need to tell UFH it's in cooling mode, or turn the thermostat up to full so the the actuators open.

 

Not sure cooling and radiators works.

[JoeBano]

I have given up trying cool with radiators doesn’t even lower the room temperature, Tried multiple fans scenarios with no luck. Gonna have to start looking to change the radiator for cooling option ones. 

[Dave Jones]

fan coils are not aircon and never will get as cold. The lowest temp needs to be above the dew point so the pipework doesn't condensate and rot out the house.

 

May be worth investing in electronically controlled blinds to stop some of the heat getting in the first place.

[yngndrw]

Just wondering if anyone can help with the configuration of the outputs for a Vaillant Arotherm Plus which we've just put in.

 

We have it all piped up with a mid-position valve to switch between cooling and heating modes and have just received the fan coil units for cooling. (Yet to install these, there was a long lead time) The way we have it piped up we can choose to either use the fan coil units just for cooling, or for both heating and cooling.

 

The fan coil units are Daikin FWS06ATV along with the FWS06ATV horizontal drain pan. We didn't get any controllers with them as I realised that the fans just need mains power and a 0-10V signal for the speed, so I'll use some 0-10V light controllers for those to pre-set the fan speeds.

 

In order to get the diverter and fans running at the right times, we need two outputs from the heat pump. Once when there's a cooling demand and one when there's a heating demand. (The cooling demand one drives the valve and the heating demand one is used to drive the fan coil unit fans when they are used for heating)

 

In the Vaillant heat pump interface, we have used MA1 for for the cooling output and MA2 for the heating output (As a zone). The manual suggests that this should be possible:

 

In the controls however, we can't find where to tell it what MA1 or MA2 actually means as the diagram suggests that it could be triggered by multiple things. Sadly we cannot test the configuration as the outside temperature needs to be above 14C for it to go into cooling mode. Can anybody help with this aspect of it? We're happy to put it into manual cooling mode when required. It's also worth noting that we have hot-water priority setup. (The hot water valve is before the heating/cooling valve)

 

As an aside, does anybody know if the Vaillant Arotherm Plus is "smart grid ready"? I believe that some heat pumps can be told to heat the cylinder to a higher temperature if there's excess solar, for example.

 

Thank you!