Fan Coil Units for use with a (cooling) ASHP

[puntloos]

On 26/05/2021 at 18:15, Ommm said:

Having done some digging around, I find there are plenty of fan coil units on Alibaba in the $100-200 range:

https://www.alibaba.com/trade/search?IndexArea=product_en&CatId=&fsb=y&viewtype=&tab=&SearchScene=&SearchText=fan+coil+

They appear to be imported into the EU and rebranded as various local brands (found some in Greece, Bulgaria).

 

Of course the suppliers are in China so you need to pay shipping and import taxes (but shipping from Italy might not be a lot different - how much does a FCU weigh?), and the unit price for small volumes may be higher.

 

The main thing that's hard to judge is the quality. But a fan coil isn't that complicated, just a motor and some metalwork, so I wonder if it would be worth the risk?

I was thinking the same thing.. if the fan breaks it's not like the thing will explode. A dead fan in an ASHP would be much more concerning. 

 

https://www.alibaba.com/product-detail/200mm-Ultra-thin-horizontal-ceiling-concealed_60757000125.html?spm=a2700.galleryofferlist.normal_offer.d_image.63de6de78wknwQ is interesting in that it's only 200mm deep, possible to hide in a void.. 

[joth]

2 hours ago, puntloos said:

 

This sounds lovely but how would you be able to split some "15C" coolant(water?) into the UFH and 5C (coolant?) into the coils?

 

This is  what the Esbe ARA662 actuator mixing valve I mentioned is for.

If Z2 (UFH) only is on, the ASHP pushes out 15C water, but if Z1 and Z2 are on it pushes out 5C to send to the fancoil, and the mixing valve closes back enough such that 15C remains circulating in the UFH

(The controller is really graceful - it completely closes the mixing valve off first then changes the primary flow temperature, then slowly opens the mixing valve until correct temp is reached, so as not to shock the system with under/over temp flow )

[Nickfromwales]

2 hours ago, puntloos said:

I was thinking the same thing.. if the fan breaks it's not like the thing will explode. A dead fan in an ASHP would be much more concerning. 

 

https://www.alibaba.com/product-detail/200mm-Ultra-thin-horizontal-ceiling-concealed_60757000125.html?spm=a2700.galleryofferlist.normal_offer.d_image.63de6de78wknwQ is interesting in that it's only 200mm deep, possible to hide in a void.. 

PM me if you go to order. I may want to give one of these a whirl and maybe we can split shipping costs?

[Nickfromwales]

3 minutes ago, joth said:

This is  what the Esbe ARA662 actuator mixing valve I mentioned is for.

I just happen to have one left surplus from a Nu-Heat install, where it was incorrectly specified and sent with an order.  

[puntloos]

48 minutes ago, Nickfromwales said:

PM me if you go to order. I may want to give one of these a whirl and maybe we can split shipping costs?

 

I'm probably 2 months away from starting to buy meaningful amounts of supplies. Let me know if that's too late

[Nickfromwales]

2 hours ago, puntloos said:

 

I'm probably 2 months away from starting to buy meaningful amounts of supplies. Let me know if that's too late

I’ve emailed to see if they’ll do a one off favourable rate inc P&P for a single unit “as a sample” ? Let’s see what they say. 

[puntloos]

1 hour ago, Nickfromwales said:

I’ve emailed to see if they’ll do a one off favourable rate inc P&P for a single unit “as a sample” ? Let’s see what they say. 

Plz report back immediately

[Dan F]

On 23/07/2021 at 21:26, joth said:

Esbe ARA662 actuator 230v 50hz 120 sec

 

The Mitsubishi FTC6 controls it all, with thermistors on all the flow and return pipes plus in the uvc and buffer tank.

You just set a desired flow temp per zone and it does the right thing when the zone calls for heat. 

 

I've checked and we have some ESBA ARA659's on-site ready to be installed.  There are the 1-10v proportional version of the same valve.  I assume these were chosen as I'd mentioned Loxone.  But, digging into the Vaillant installation guides it seems that Vailant also supports multiple "mixed circuits" with different flow temperatures and weather compensation curves, so I think I'd better get these switched out to 230v SPDT versions so that this can all be setup up and and commisioned as part of the ASHP install.  If it works well and adjusts the ASHP flow temp based on the circuits which are on/off and their target temperatures then  they'll be no reason to do anything myself.

 

 

 

[Ommm]

19 hours ago, puntloos said:

Plz report back immediately

 

I'd definitely be up for a shared order.  I was talking to these folks:

https://yuexinlengnuan.en.alibaba.com/

as they have a radiator-replacement FCU for ~$150:

https://yuexinlengnuan.en.alibaba.com/productgrouplist-823836568/ultra_thin_fcu_radiator.html

They do ceiling ones too - do any of these match what you need? (see also the other categories)

https://yuexinlengnuan.en.alibaba.com/productgrouplist-823312868/ultra_thin_concealed_horizontal_fcu.html

 

They quoted ~$320 for UK shipping. That's likely air freight.  It'll cost roughly the same for a pallet to go by sea (~40 days) but multiple units could fit on a pallet.

 

Do PM me for further plotting ?

 

[puntloos]

3 hours ago, Ommm said:

 

I'd definitely be up for a shared order.  I was talking to these folks:

https://yuexinlengnuan.en.alibaba.com/

as they have a radiator-replacement FCU for ~$150:

https://yuexinlengnuan.en.alibaba.com/productgrouplist-823836568/ultra_thin_fcu_radiator.html

They do ceiling ones too - do any of these match what you need? (see also the other categories)

https://yuexinlengnuan.en.alibaba.com/productgrouplist-823312868/ultra_thin_concealed_horizontal_fcu.html

 

They quoted ~$320 for UK shipping. That's likely air freight.  It'll cost roughly the same for a pallet to go by sea (~40 days) but multiple units could fit on a pallet.

 

Do PM me for further plotting ?

 

Slightly offtopic but how do 'we' feel about alibaba style orders anyway? I was debating a wall-mounted kitchen tap but well, just as with fan coils, I'm fairly worried that if they fail, getting replacements is a nightmare, or you'd have to go with a completely different brand, possibly local which might mean the fittings will be useless etc. 

 

Is aliexpress/alibaba a good idea? ?

[joth]

Yeah for aliexpress orders I've always added up the price, lifetime I'd "like" to get out of the thing, the hassle of completely replacing it or repairing if it dies, availability of UK based parts or replacement, and how much loss of function it will cause if it does fail.

 

Most my AliExpress orders were for solid state relays, low voltage lighting  drivers (feature lighting: easy to live without if it fails, and central cabinet installed makes it easy to replace), motion sensors (I thought easy to live without, but I admit would be very annoying if the did all go, but each one is easy enough to replace on its own anyway).

Probably the most critical item is the DMX amplifier / splitter.  

 

For a wall-integrated tap / mixing valve, or for a FCU (esp one that is "burried" in a ceiling void) it's not very promising.  Mostly the hassle of trying to get to it to repair/replace is going to be high

 

Also note that cheap mixer taps like that (we got a similar deck-mounted one) don't have integrated TMV so the hot temp varies a bit unpredictably depending if the sun has been out (PV redirect was on).   You can add central TMV to limit highest temp, but that is annoying for running a bath and can limit overall flow/pressure.   I guess having a  central manifold would restricted temperature DHW to some taps, but unlimited to others where it makes sense (bath, shower, etc)

 

[puntloos]

1 hour ago, joth said:

For a wall-integrated tap / mixing valve, or for a FCU (esp one that is "burried" in a ceiling void) it's not very promising.  Mostly the hassle of trying to get to it to repair/replace is going to be high

Yeah, I'm probably indeed going to pass. (my alternative was to literally order 3 )

1 hour ago, joth said:

Also note that cheap mixer taps like that (we got a similar deck-mounted one) don't have integrated TMV so the hot temp varies a bit unpredictably depending if the sun has been out (PV redirect was on).   

I must say that one is *surprisingly* similar to those FLG ones. I guess there's only so much you can do with a tap (but I wouldn't be surprised if 'Sauber' really is just a rebrand?)

 

But yeah, my main reason for the wall mounting is ease of cleaning (99.9% of taps I've observed in kitchens have a nice ring around the mounting spot) but .. it's kinda 1st world problem to have

 

1 hour ago, joth said:

You can add central TMV to limit highest temp, but that is annoying for running a bath and can limit overall flow/pressure.   I guess having a  central manifold would restricted temperature DHW to some taps, but unlimited to others where it makes sense (bath, shower, etc)

 

TMVs are effectively an unsolved problem as far as I can tell. Not because a brand new one won't work, but limescale (even if descaled) will affect the function soon..

[jack]

On 23/07/2021 at 18:50, MortarThePoint said:

This is cool, literally. If just looking to cool the floor, is it just a matter of having the right ASHP?

 

Yes. On many ASHPs you'll need to enable cooling mode via the control panel. It isn't always in the user manual - ours (Panasonic) came with a slip of paper in the box with instructions for how to access this mode.

 

On 23/07/2021 at 18:50, MortarThePoint said:

Sending 15C water through the UFH pipes feels pretty low risk from a condensation perspective. If concerned by condensation on the manifold, one can always run a separate dehumidifier nearby or perhaps just a fan blowing over their surface.

 

A dehumidifier would be overkill imo, but sure, you could run a small fan if the condensation worried you. I only have our cooling on during long hot spells, like we had in the south east last week, so I'm not concerned about long term damage from condensation. 

[Donegalsd]

Hi,

Has anyone found a UK or Eu website (other than shopclima) that sells fan coil units and has prices on website.

I'm looking to price one that can be ducted to 3 or four bedrooms.

I'm reluctant to order from Ali ect.

 

Thanks

 

 

[joth]

31 minutes ago, Donegalsd said:

Hi,

Has anyone found a UK or Eu website (other than shopclima) that sells fan coil units and has prices on website.

I'm looking to price one that can be ducted to 3 or four bedrooms.

I'm reluctant to order from Ali ect.

 

Thanks

 

 

This place has a public price list https://ampair.co.uk/wp-content/uploads/2020/06/AMP-AQUAREA-PRICE-LIST-20-FINAL.pdf (page 31). Good luck actually sourcing one.

 

Learn from my mistakes:

1/ size the FCU(s) appropriately to use the full capacity of your chosen ASHP without causing it to short cycle. I went for a PAW-FC-D15-1 which is way too small for a 8.5kW ecodan.

2/ pay attention to the "water pressure drop" figure. I really have little idea what this is for, but if you intend to have >1 FCU (or add more in future of different sizes) I believe matching them all with same/similar water pressure drop figures will make balancing the system much easier. (Else, perhaps one could use a manifold with salus autobalancing actuators or similar to manage water flow through them, but that's yet more complexity.

- again the PAW-FC-D15-1 I have is very low water pressure drop compared to any other, so I would have to bear this in mind if adding more (or, throw out my current one and start over) 

- aside: why would water pressure drop vary depending on fan speed? Something odd going on in the thermodynamics I don't understand there.

3/ installing a large buffer tank would also help match smaller FCU(s) to a larger ASHP 

 

[Ommm]

On 28/07/2021 at 12:53, Donegalsd said:

Hi,

Has anyone found a UK or Eu website (other than shopclima) that sells fan coil units and has prices on website.

I'm looking to price one that can be ducted to 3 or four bedrooms.

I'm reluctant to order from Ali ect.

 

Look up 'ventilconvettore' - there are quite a number of suppliers in Italy, where they seem to be popular.

 

Here's a price comparison for example:

https://www.trovaprezzi.it/prezzo_climatizzazione_ventilconvettore.aspx

(for examples of suppliers that list prices, rather than the specific models they have there)

 

As to who will ship to the UK post-Brexit, that's another question...

(perhaps need a freight consolidator in Italy? Or drive to Calais...?)

Edited July 29, 2021 by Ommm

[Donegalsd]

Thanks Both,

 

I'm in ROI so should be OK for delivery. Now I just need to find my Italian friend to help me navigate the sites.

 

[Ommm]

On 29/07/2021 at 13:51, Donegalsd said:

Thanks Both,

 

I'm in ROI so should be OK for delivery. Now I just need to find my Italian friend to help me navigate the sites.

 

I had a look through the sites and most are Italy-only.  I did find: https://www.promoclima.it/ who will quote for delivery to the UK (for 1x large-ish radiator fan coil about EUR60, which sounds about right, for 3x is EUR215, which is a bit steep but probably what it costs for 3 parcels to go UPS. Their list prices are probably ex-VAT, plus customs fees).  They list shipping for most of the EU but not Ireland for some reason - worth asking, or presumably UK includes NI and maybe you have a friend across the border...

(whether they will actually go through with a transaction to the UK is another question, but they let me get as far as payment)

 

For the FCU that was EUR215 plus EUR60 delivery, Sabiana UK quoted £324+VAT plus delivery (which for 3 FCUs was £70+VAT).  So not a huge deal in it if buying multiples.

 

The alternative is one of the 'parcel forwarding' companies intended for online shopping that can consolidate onto a pallet.  I asked SourcingItaly for a quote but they said they're out of warehouse space at present.  I might try others, but not sure it'll be much improvement on EUR215, and probably pallets are a bit too big for many of them.  Might make sense for more units though.

 

[joth]

18 minutes ago, Ommm said:

I did find: https://www.promoclima.it/ who will quote for delivery to the UK

Yes, that's where I got mine (see previous pages of this thread for details)

It was Pre-brexit mind you. 

[Mr Blobby]

On 25/07/2021 at 20:43, joth said:

 

This is  what the Esbe ARA662 actuator mixing valve I mentioned is for.

If Z2 (UFH) only is on, the ASHP pushes out 15C water, but if Z1 and Z2 are on it pushes out 5C to send to the fancoil, and the mixing valve closes back enough such that 15C remains circulating in the UFH

(The controller is really graceful - it completely closes the mixing valve off first then changes the primary flow temperature, then slowly opens the mixing valve until correct temp is reached, so as not to shock the system with under/over temp flow )

 

Thank you for sharing this, your panasonic FCUs and mixing valve look like a really neat solution to get cooling (and heating) upstairs (without rads) while also cooling the UFH. 

 

I assume the mixing valve works ok when heating, with, say, >=40 C flow to the FCUs and <=25 C to the UFH? 

 

How about the physical install?  Did you install in the loft (asuming a warm roof) with cooled-air ducting to the walls or ceiling? 

What about the air intake? I assume you can just let this recircuate loft air without any ducting?

 

Edited September 5, 2021 by Mr Blobby
clarification

[joth]

4 hours ago, Mr Blobby said:

 

I assume the mixing valve works ok when heating, with, say, >=40 C flow to the FCUs and <=25 C to the UFH? 

 

Installed in May so FCU only used for cooling. It's never cold upstairs so I doubt we'll ever use it for heating, but the very quick test I did on install it seemed fine.

 

4 hours ago, Mr Blobby said:

How about the physical install?  Did you install in the loft (asuming a warm roof) with cooled-air ducting to the walls or ceiling? 

Yeah in the warm loft, 125mm duct direct into a circular ceiling vent. 

The return is via loft air. There's a risk this picks up more dust, no issue seen so far. And Nick says it may unbalance the mvhr but we don't run it enough that really worries me. (the q350 stats don't seem to show any change in overall flow when it's on)

 

 

 

 

 

[Omnibuswoman]

I’m also interested in sharing an order on one of these FCUs. Not sure if it’s helpful but my brother lives in Ireland…

[Dan F]

9 hours ago, Omnibuswoman said:

I’m also interested in sharing an order on one of these FCUs. Not sure if it’s helpful but my brother lives in Ireland…

I saw you had PHPP done in other thread.  What was your "cooling load"? If you have already mitigated the majority of overheating risk using overhangs, blinds etc. and know that your "cooling load" is very low,  then you could consider a MVHR heat battery (VEAB or ComfoPost).  This doesn't require FCU per-room and all plumbing stays central. In our case, our calculated cooling load was 335W,  with the UFH able to supply 3.6kW (ground floor) and MVHR ComfoPost (first-floor) 1.1kW which is clearly plenty.

[Omnibuswoman]

Good question! I’ve just checked and that wasn’t calculated (we only asked them for an overheating assessment/advice and the calculations and shading strategy met that brief).
 

I have assumed that even with the shading strategy we have, excess heat would still pass through the walls during extended periods of very high temperatures, and that in periods when the outside temperature doesn’t fall below 20c at night we would want to cool our bedroom down for comfort. 
 

I had thought that MHRV wouldn’t be sufficient for this, but it sounds as though it could be. Our builder, who is passive house trained, will do our M&E work later on. I’ll ask him about this idea. 
Thanks! M
 

 

[Dan F]

1 hour ago, Omnibuswoman said:

Good question! I’ve just checked and that wasn’t calculated (we only asked them for an overheating assessment/advice and the calculations and shading strategy met that brief).

 

If you have the spreadsheet you can make "cooling load" appear by enabling "mechanical cooling" (N29).

 

1 hour ago, Omnibuswoman said:

I had thought that MHRV wouldn’t be sufficient for this, but it sounds as though it could be. Our builder, who is passive house trained, will do our M&E work later on. I’ll ask him about this idea. 

 

May not be suitable, but if i) you are building to PH standard ii) have PHPP with cooling load iii) having a heat pump, then worth considering.