Fan Coil Units for use with a (cooling) ASHP

[joth]

22 hours ago, Nickfromwales said:

I went with 2x regular MVHR ceiling valves with 2x lower extracts in 225x25mm, each with their own 92mm ducts on a previous install. Was a little less ‘prominent’ than that one.

 

 

LOL I had thought what I'd achieved was pretty discrete actually. Maybe I'm biased by what I sit underneath in the office: Now that's prominent! 

 

Edited June 30, 2022 by joth

[joth]

On 25/07/2021 at 21:36, puntloos said:

 

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

 

How did the Alibaba ordering go - did anyone end up trying it? (1 year on - such as seasonally dependent conversation this I know!!).

 

I'm ready to order 2 more FCUs (2 pipe water, 1.5-2kW cooling). Ideally I'd get the same as before, PANASONIC PAW-FC-D15, but they seem impossible to source now, as does pretty much anything like it.

 

I've found this rather oversized 4kW FCU on ebay which could possibly be ducted in to serve both rooms.
Splitting one FCU to two rooms suggests controlling the flow to each room via duct dampers with electric actuators (https://www.aliexpress.com/item/32825795338.html or https://www.aliexpress.com/item/33007338157.html), which is yet another set of relays and control logic needed. Hmmmm

 

Only snag is it's 4-pipe (which seems odd for a water-based system) and I'm not sure what I'd do with the spare pipes. In my mind, I could plumb both in to get full use of both coils. Connecting both coils in series is less pipework joints, but in parallel probably less pressure drop. 

[LA3222]

56 minutes ago, joth said:

 

How did the Alibaba ordering go - did anyone end up trying it? (1 year on - such as seasonally dependent conversation this I know!!).

 

I'm ready to order 2 more FCUs (2 pipe water, 1.5-2kW cooling). Ideally I'd get the same as before, PANASONIC PAW-FC-D15, but they seem impossible to source now, as does pretty much anything like it.

 

I've found this rather oversized 4kW FCU on ebay which could possibly be ducted in to serve both rooms.
Splitting one FCU to two rooms suggests controlling the flow to each room via duct dampers with electric actuators (https://www.aliexpress.com/item/32825795338.html or https://www.aliexpress.com/item/33007338157.html), which is yet another set of relays and control logic needed. Hmmmm

 

Only snag is it's 4-pipe (which seems odd for a water-based system) and I'm not sure what I'd do with the spare pipes. In my mind, I could plumb both in to get full use of both coils. Connecting both coils in series is less pipework joints, but in parallel probably less pressure drop. 

You got a link to that ebay unit bud, may have to look into the use of a FCU for cooling of the bedrooms.

[Ommm]

3 hours ago, joth said:

 

How did the Alibaba ordering go - did anyone end up trying it? (1 year on - such as seasonally dependent conversation this I know!!).

Well, sorta.

 

Things have been somewhat complicated by my "customer" not being able to tolerate even tiny amounts of noise, especially when sleeping.  That rules out a lot of commercial units, especially those Alibaba specials who are a bit sketchy about noise levels.  I suggested a ducted unit in the loft, but that was not acceptable.

 

However, on my travels I came across this:

https://www.aliexpress.com/item/1005004090666621.html

which is the wet guts of a 460x200mm fan coil unit, minus the fan.  It was about $90 delivered, so I thought it worth a punt.  Took about 10 days from China, which was quite impressive. And here it is:

 

(yes it's leaking, that's because my garden hose is useless, don't judge)

 

That's with two Bitfenix Spectre Pro 230mm computer fans on it.  It's almost inaudible when connected to a car battery at about 12.6v (at least in comparison to outdoor ambient sound)

 

It's a 3 row coil: at the intake (at the bottom here) the 3/4" fitting splits into three rows of copper coils, which go around in serpentine fashion before emerging in the 3/4" fitting at the top.

 

When fed with mains water on test (not sure what temp it comes out of the pipes in the summer, something like 12-13C?) there's a pleasant cooling breeze come out of the other side if you put your hand within a couple of inches, but it's not very strong.  I'd rather like the fans to be a bit stronger, but I can't seem to find quiet but more powerful fans in this kind of size - it's overkill for PC cooling.  These ones are each 160cfm at 900rpm and 1.81 mmH2O static pressure - I'd really like something about 3-4x that CFM.  Or possibly another fan downstream to 'throw' the air into the room so that it mixes properly.  I could I suppose try a battery of smaller fans - that's something else to test.

 

To be continued...

[Wil]

16 hours ago, LA3222 said:

You got a link to that ebay unit bud, may have to look into the use of a FCU for cooling of the bedrooms.

Or the link to the oversized 4kW unit?

[joth]

8 hours ago, Wil said:

Or the link to the oversized 4kW unit?

https://www.ebay.co.uk/itm/265700372361

 

I was withholding sharing that to avoid bidding against y'all, but on the fence about buying a used FCU at all so no worries if someone else decides to shoot for it. I anyone does, I'll interested how you deal with the 4 water pipe connection?

 

(To confirm I'm not ebaying for cost savings just the lack of availability anywhere else)

[Ommm]

4 pipe is if you want the same FCU to do heating and cooling - in commercial environments you have a separate boiler and chiller, so you run two sets of pipework around the building.  Particularly important if some rooms want heat and some want cooling at the same time.  (eg server rooms always want cooling, even in winter)

 

You'd need to check the valve and control arrangement.  If you're running a single loop from an ASHP that switches from heat to cool depending on the weather you only need to plumb one set of pipes, but you need to ensure whatever valve is on there is set up correctly.  I suppose you could plumb both loops into the same source (in series, in parallel?) if you wanted.

 

Typically FCUs have a 4 port valve, basically that means you have a position where the water flows through the FCU loop and another position where the water bypasses the FCU. You then loop the water from the chiller through every 4 port valve around the building. I imagine a 4 pipe unit will have two 4 port valves.  I'm assuming you'd need to wire your own thermostat for the 4-port valve and the fan (there are plenty of standalone and wifi FCU thermostats on Aliexpress, I bought one... it's nothing fancy but looks ok)

 

I don't see anything particularly wrong with a second hand FCU, I'd just look for signs of corrosion and look at giving the motors some TLC when you receive it.  I'm not sure what the situation is with replacement parts if any are needed.

[joth]

1 hour ago, Ommm said:

4 pipe is if you want the same FCU to do heating and cooling - in commercial environments you have a separate boiler and chiller, so you run two sets of pipework around the building.  Particularly important if some rooms want heat and some want cooling at the same time.  (eg server rooms always want cooling, even in winter)

 

You'd need to check the valve and control arrangement.  If you're running a single loop from an ASHP that switches from heat to cool depending on the weather you only need to plumb one set of pipes, but you need to ensure whatever valve is on there is set up correctly.  I suppose you could plumb both loops into the same source (in series, in parallel?) if you wanted.

 

Typically FCUs have a 4 port valve, basically that means you have a position where the water flows through the FCU loop and another position where the water bypasses the FCU. You then loop the water from the chiller through every 4 port valve around the building. I imagine a 4 pipe unit will have two 4 port valves.  I'm assuming you'd need to wire your own thermostat for the 4-port valve and the fan (there are plenty of standalone and wifi FCU thermostats on Aliexpress, I bought one... it's nothing fancy but looks ok)

 

I don't see anything particularly wrong with a second hand FCU, I'd just look for signs of corrosion and look at giving the motors some TLC when you receive it.  I'm not sure what the situation is with replacement parts if any are needed.

 

Cheers. Yeah I was aware in principle of the idea of 4-pipe FCU (I sit underneath a zillion of them in my office per the photo up thread) but wasn't sure if I can easily/sensibly use one in a 2-pipe installation like my house. TBH if there's a diverter valve on the input why bother having 2 coils? just to avoid mixing hot and cold at the change over? Seems more space efficient to have a single coil and divert either the hot loop or cold loop into it according to conditions. (For refrigerant appreciate it's very different, but for a w2a heat exchanger seems simple enough).

I should probably search for some more schematics of typical installs 🙂

 

I did message the seller a couple days ago to ask what the valves and accessories attached to it are in the 3rd photo, but tbh don't expect to get a reply looks like a large scale ebay seller with payment in advance, collection only and no returns, and no responses to enquiries, and some poor reviews. Shame as otherwise I'd probably just take a punt on it. (especially if the price was a bit more at the "couldn't go wrong" end, seeing as collection is very local to me).

You advice on buying used it handy though, many thanks!

 

 

[joth]

5 minutes ago, joth said:

TBH if there's a diverter valve on the input why bother having 2 coils? just to avoid mixing hot and cold at the change over? Seems more space efficient to have a single coil and divert either the hot loop or cold loop into it according to conditions. (For refrigerant appreciate it's very different, but for a w2a heat exchanger seems simple enough).

I should probably search for some more schematics of typical installs 🙂

OK answering my own question, if the hot and cold are coming from different sources you  want to keep them entirely hydronically separated, to keep expansion vessels, glycol etc completely independent.  Yeah makes sense, even if it results in half the coils being in the airflow but idle at any given time.

[MikeSharp01]

Just posted this on another thread thought it had better be here as well:

 

We have the passive slab, will have the ASHP, so now if I can find some small fan coil units, we have only vaulted ceilings with a small flat spot at the top which has limited room but I found this fan coil unit:

 

Image: https://www.hitachiaircon.com/hk/en/ranges/airside-systems/fan-coil-unit but I cannot find this on any Hitachi / Johnson controls UK site but scaling from the inlet/outlet pipes we might get it into the ceilings. Anybody recognise it?

[SteamyTea]

32 minutes ago, MikeSharp01 said:

Anybody recognise it?

Can you do a Google image search and see what comes up?

[Nickfromwales]

1 hour ago, MikeSharp01 said:

Just posted this on another thread thought it had better be here as well:

 

We have the passive slab, will have the ASHP, so now if I can find some small fan coil units, we have only vaulted ceilings with a small flat spot at the top which has limited room but I found this fan coil unit:

 

Image: https://www.hitachiaircon.com/hk/en/ranges/airside-systems/fan-coil-unit but I cannot find this on any Hitachi / Johnson controls UK site but scaling from the inlet/outlet pipes we might get it into the ceilings. Anybody recognise it?

Can you not mount this remotely and run multiples of insulated ducts to the space it needs to service?
Did this on one project where I installed 2x 92mm ducts for return air, low down at the far ends of the room, and then another 2x 92mm ducts for supply of fresh / cool air. 4 ducts at the source and then you could just use a centrifugal fan and 3 row heat cool units from ( for eg ) BPC.

 

[joth]

1 hour ago, MikeSharp01 said:

Just posted this on another thread thought it had better be here as well:

 

We have the passive slab, will have the ASHP, so now if I can find some small fan coil units, we have only vaulted ceilings with a small flat spot at the top which has limited room but I found this fan coil unit:

 

Image: https://www.hitachiaircon.com/hk/en/ranges/airside-systems/fan-coil-unit but I cannot find this on any Hitachi / Johnson controls UK site but scaling from the inlet/outlet pipes we might get it into the ceilings. Anybody recognise it?

 

Yeah this is pretty typical, you can  find images of all sorts of FCUs online, but finding a distributor/reseller for any of them is a real struggle.

 

e.g. I have this one, rebranded as panasonic https://shop.systemair.com/en/scc202plg2/p402066

And back up thread puntaloos found this Carrier slimline unit (specs) that would fit in a ceiling void.

 

But, unless you're building a block of flats or a large office, the suppliers really aren't interested to talk to you.

 

 

[Ommm]

52 minutes ago, joth said:

 

Yeah this is pretty typical, you can  find images of all sorts of FCUs online, but finding a distributor/reseller for any of them is a real struggle.

Judging by this pic of the innards from Hitachi Singapore:

 

it looks extremely similar to my Aliexpress special upthread.  I assume this is a rebrand of some generic FCU, possibly Chinese.  From an image search, it is notable that it shows up on the website of Hitachi Hong Kong, Singapore and Thailand, but no European websites.  I'd expect it's a bit like buying cylinders from boiler manufacturers: they don't make them, they just subcontract somebody else (perhaps to special order) and rebrand.  It's quite possible every country or region has their own local supplier, to save transport costs.

 

Here's a brochure from the Philippines which has some part numbers, although looks different:
http://www.jci-hitachi.ph/uploads/download_catalog/163_2.pdf
 

My general experience is the Italians (and their UK agents) are easier to deal with, because it's not infeasible to ship stock over from Italy, whereas delivery from Asia is going to involve a container ship.  However every quote I got was in the region of £500 per (radiator-style) unit, so not cheap.

[joth]

11 minutes ago, Ommm said:

My general experience is the Italians (and their UK agents) are easier to deal with, because it's not infeasible to ship stock over from Italy, whereas delivery from Asia is going to involve a container ship.  However every quote I got was in the region of £500 per (radiator-style) unit, so not cheap.

Yeah mine was shipped from italy fine (well, some serious box damage, but works fine). but they have nothing in stock anymore

https://www.shopclima.it/it/panasonic-paw-fc-d15-1-ventilconvettore-compatto-aquarea-con-attacco-lato-sx-1-5-kw.html

 

[MikeSharp01]

1 hour ago, joth said:

e.g. I have this one, rebranded as panasonic https://shop.systemair.com/en/scc202plg2/p402066

And back up thread puntaloos found this Carrier slimline unit (specs) that would fit in a ceiling void.

 

But, unless you're building a block of flats or a large office, the suppliers really aren't interested to talk to you.

 

Thanks - that's all interesting but I don't think any of them will fit in our void, I also would need to plumb the condensate out and, because we don't want to bring outside air in, other than via the MVHR, we would need to recirculate which looks like it adds to complexity somewhat!

 

I think I am going to look harder at getting the MVHR boost to deliver a modicum of cooling - if I get ahead of it I feel, just gut feel, we might achieve it so I need to get back to the sums.

 

See this thread:

 

 

Edited July 19, 2022 by MikeSharp01
Added link to secondary thread.

[joth]

On 12/07/2022 at 20:17, joth said:

https://www.ebay.co.uk/itm/265700372361

 

I was withholding sharing that to avoid bidding against y'all, but on the fence about buying a used FCU at all so no worries if someone else decides to shoot for it. I anyone does, I'll interested how you deal with the 4 water pipe connection?

 

(To confirm I'm not ebaying for cost savings just the lack of availability anywhere else)

 

Well being as it was hottest UK day ever I figured wtf and went over and picked up this 4 pipe FCU. Tested the fan and it's very quiet especially on low. Already ordered a new plenum box for it. 

The wet end looks like this. I'm tempted to remove the actuators completely and plumb the two coils in series. It's rated at 4.5 kW on one coil for cooling so I'm hopeful it will make a reasonable sized sink for our ASHP

 

[markocosic]

Probably needs parallel plumbing for pressure drop reasons 

[Ommm]

If anyone wants a Chinese radiator-style unit, this seller made me an offer for £250 + £28.55 delivery and seems to have lots of stock, so I'm sure would be amenable to others making a similar offer:
https://www.ebay.co.uk/itm/403556834346

 

[joth]

23 hours ago, Ommm said:

If anyone wants a Chinese radiator-style unit, this seller made me an offer for £250 + £28.55 delivery and seems to have lots of stock, so I'm sure would be amenable to others making a similar offer:
https://www.ebay.co.uk/itm/403556834346

 

Be interested how you get on, but I discarded that one as it has such little tech info. e.g. I'd like a model number, and to see wiring and plumbing schematic and what condensate tray it has (if any). 

(Also I needed air ducted unit, although that one looks like it maybe within realms of possibility to fit some kind of plenum cowl over).

 

[Ommm]

32 minutes ago, joth said:

Be interested how you get on, but I discarded that one as it has such little tech info. e.g. I'd like a model number, and to see wiring and plumbing schematic and what condensate tray it has (if any). 

(Also I needed air ducted unit, although that one looks like it maybe within realms of possibility to fit some kind of plenum cowl over).

 

It's a generic Chinese unit, the likes of which are all over Alibaba:
https://www.alibaba.com/product-detail/KDGD-OEM-vertical-exposed-fcu-radiator_1600180479418.html
https://www.alibaba.com/product-detail/Ultra-thin-floor-fan-coil_60529885215.html

https://www.alibaba.com/product-detail/130mm-floor-standing-ultra-thin-fan_1600180883756.html
The specs will mostly depend on the dimensions, as they come in about 5 different lengths.  This vendor doesn't specify the size (would need to ask), but it doesn't look like a large one.

Plumbing: I think there's two threaded water connections to the coil (I'd guess DN20 aka 3/4" BSP like mine): any valve work is your problem (I think there's some space for valves inside the unit - it looks like the ebay listing comes with a valve).  Condensate wise, there's no view of the tray but the Ali pics show a corrugated condensate drain pipe - I think they can be ceiling mounted, but worth checking. Electrically, they're mostly AC motors so they usually have three speeds controlled by energising separate mains windings.

 

The controller on the top is generally a bit basic, as depicted in the last Alibaba link: there's some relay contacts for the valve and for the fan speed, there's a thermistor going through a small hole in the side for the room temperature, and some buttons for temp +/- and fan speed +/-.  It's really just a basic thermostat with some fan buttons. I'm not 100% but I think the place where the controller sits is a standard size so can be swapped out for a different standard controller - there are versions with wifi and RS485 on Aliexpress.  I think you can also get them without panel where you just wire the motor and valve directly from another controller.

 

There's really nothing fancy: it's pretty simple really.  Most fan coils are quite simple - they might work standalone, but if you want to integrate them you need to do a little plumbing and electrical work.  But there's not much to it.

[joth]

On 11/07/2022 at 17:53, joth said:

 

I'm ready to order 2 more FCUs (2 pipe water, 1.5-2kW cooling). Ideally I'd get the same as before, PANASONIC PAW-FC-D15, but they seem impossible to source now, as does pretty much anything like it.

 

I've found this rather oversized 4kW FCU on ebay which could possibly be ducted in to serve both rooms.

 

On 19/07/2022 at 22:12, joth said:

 

Well being as it was hottest UK day ever I figured wtf and went over and picked up this 4 pipe FCU. Tested the fan and it's very quiet especially on low. Already ordered a new plenum box for it. 

The wet end looks like this. I'm tempted to remove the actuators completely and plumb the two coils in series. It's rated at 4.5 kW on one coil for cooling so I'm hopeful it will make a reasonable sized sink for our ASHP

 

 

So.

I still haven't got around to installing that second FCU that I bought on ebay back in, what?? July. (Were does the time go? Oh yeah I know)

And now I noticed that the Panasonic FC-D15 I originally was looking to purchase is (possibly?) available in the UK now:

https://www.saturnsales.co.uk/Panasonic-Aquarea-PAW-FC2A-Ducted Fan Coils.html

 

They appear to have arsed about with their numbering scheme, latest brochure says that the  FC-D15-1(-R)  I ordered way back in 2020 is now known as the FC2A-D020[L/R] but otherwise the specs seem identical. It seems the main thing is they've now introduced 4-pipe versions of each too.

 

Anyway, if people are looking to source FCUs in the UK, there maybe another option now.

[eniacs]

Ordered my fancoil from www.idrocrimart.it. They charged $100 euro shipping to "europe" which included the UK. Bought this model:  

SL 400 C

Total cooling capacity W 7/12 °C / A 27 °C 2,12 kW
Heating capacity W 45/40 °C /A 20 °C 2,21 kW
Indoor unit dimension↔935 mm↔579 mm↔129 mm

 

Total cost $595. I've gone for the expensive $150 euro full digital control panel. There were cheaper ones. The basic fan coil rad was $350. Its made by Innova who also make the panasonic aquarea's mentioned above. 

 

Will let you know how it turns out, if its a good unit i need 6 more! If its not I've lost money lol.

[eniacs]

8 hours ago, eniacs said:

Ordered my fancoil from www.idrocrimart.it. They charged $100 euro shipping to "europe" which included the UK. Bought this model:  

SL 400 C

Total cooling capacity W 7/12 °C / A 27 °C 2,12 kW
Heating capacity W 45/40 °C /A 20 °C 2,21 kW
Indoor unit dimension↔935 mm↔579 mm↔129 mm

 

Total cost $595. I've gone for the expensive $150 euro full digital control panel. There were cheaper ones. The basic fan coil rad was $350. Its made by Innova who also make the panasonic aquarea's mentioned above. 

 

Will let you know how it turns out, if its a good unit i need 6 more! If its not I've lost money lol.

Order cancelled from idriocrimart. Apparently it is in their terms not to ship to UK.

 

Order placed from hydroexpertsrl.it. Rad was only $250euro (no vat i think). Total $459euro with a cheaper controller (expensive one not stocked here sadly). Considered proclima as they stock the better controller but their minimum postage is $250euro! However only 600 delivery for 7 units.

[eniacs]

Also cancelled from hydroexpert. Damn brexit, they say there are too many forms to fill to ship it.