Fujitsu J series

[Pingo]

Any body have any experience with Fujitsu J series small VRF systems ?

I have a large house with 4 bedrooms to cool and there may be a new Conservatory at a later date (Conservatory is just being built at this present time )

A couple of questions for the people who have worked on them:

Are the Electronic valves (E.V Kits) noisy in operation and what is the lowest load they can operate on,
I have one bedroom which will only require a 2Kw wall unit


Regards pingo

[paul_h]

No, they are pretty quiet.
I have only worked on a few and fuji australia hasn't given me much info on them. The new zealand site has a PDF and more info on them though. A quick read through suggests they are compatible with the ao*7, which is a 2.15kw wall split
http://www.fujitsugeneral.co.nz/vrf-j-series.html

[Greengrocer]

New to RE but not industry.
Do you have to use Fujitsu J series?
If not consider MHI's FDCVA140 KX4 Mini VRF system. Indoor units have EEV's fitted at standard not in pipe-work. Only snag with this outdoor unit is its the larger twin fan type and indoors are a bit agricultural to look at. However it is about to be replaced by the new KX6 which is a single fan design like the J series but far more efficient and has a 150% connection ratio.
FDCVA140 units are on special with 3D/HRP as they try to run down stock before launch on new model.

[nike123]

New to RE but not industry.
Do you have to use Fujitsu J series?
If not consider MHI's FDCVA140 KX4 Mini VRF system.

It would be nice that you say why you advising use of MHI instead of Fujitsu. Or you maybe have personal interest as regional manager (of what) in that?

[Greengrocer]

It would be nice that you say why you advising use of MHI instead of Fujitsu. Or you maybe have personal interest as regional manager (of what) in that?


No personal interest - I'm an A/C contractor. Just prefer systems which don't have loads of extra and uneccessary joints and field installed components.
The J series system uses "split" indoor units (not VRF) so each indoor needs a separate EEV kit to be compatible.
Also difficult to hide the Fujitsu EEV's if pipework is in trunking (not so bad if pip-work is in loft space). Daikin, ME, Hitachi, Sanyo and others offer Mini VRF systems all of which use pukka VRV/VRF indoor units with integral EEVs. I have always found MHI as good as the more expensive brands and more competitive. The new model will be even better than the old and is more efficient than the Fujitsu which is not ECA approved in UK due to its low EER/COP. If the install is for a house then homeowners are often swayed by the look of the indoor units (I assume hi-walls). In that case LG may be on the menu (Artcool). Personally I wouldn't offer an LG system on principle after some bad experiences in the past.
Only trying to help with a few alternative suggestions.

[Daikin=Overated]

No personal interest - I'm an A/C contractor. Just prefer systems which don't have loads of extra and uneccessary joints and field installed components.
The J series system uses "split" indoor units (not VRF) so each indoor needs a separate EEV kit to be compatible.
Also difficult to hide the Fujitsu EEV's if pipework is in trunking (not so bad if pip-work is in loft space). Daikin, ME, Hitachi, Sanyo and others offer Mini VRF systems all of which use pukka VRV/VRF indoor units with integral EEVs. I have always found MHI as good as the more expensive brands and more competitive. The new model will be even better than the old and is more efficient than the Fujitsu which is not ECA approved in UK due to its low EER/COP. If the install is for a house then homeowners are often swayed by the look of the indoor units (I assume hi-walls). In that case LG may be on the menu (Artcool). Personally I wouldn't offer an LG system on principle after some bad experiences in the past.
Only trying to help with a few alternative suggestions.

Well said that man!

[nike123]

Fair, that is argumentation I like!

[ozairman]

The EV kits can be mounted up to 1.2m away from the indoor units on the compact wall mounted series (AS7,9,12,14) use this if putting the indoor in a bedroom, there is a small amount of refrigerant bypass flow during operation even with the head unit switched off.

[ozairman]

You are right about the EEV but tell me who of the big names DAIKIN,MITSI.... has done an outdoor machine like J series size 900mm x 900 mm giving you 22.8 kw.I like the DAIKIN and MITSI a lot but i feel sad that they don't offer this exclusive machine.On top of that you can decide what size circuit breaker to fit starting from 16 A.....you can't believe it isn't it check the installation manual.;)
Just remember that 22.8kW is 150% connected capacity and make sure your end user understands they only have 15.2kW of capacity to spread around (unfortunately most don't ;)). Also you will not get 15.2kW of capacity from the outdoor unit if input current is limited to 16A, you need the 30A supply if you want maximum performance. But as you say the compact size of the outdoor unit is fantastic when compared to what else is around

[Greengrocer]

Just remember that 22.8kW is 150% connected capacity and make sure your end user understands they only have 15.2kW of capacity to spread around (unfortunately most don't ;)). Also you will not get 15.2kW of capacity from the outdoor unit if input current is limited to 16A, you need the 30A supply if you want maximum performance. But as you say the compact size of the outdoor unit is fantastic when compared to what else is around

I agree that the J Series was way ahead of it's time when it first came out but new MHI KX6 VRF outdoor units better the J series in just about every dept eg. 845 x 970 x 370 (HWD), available in nominal 11.2, 14 & 15.5kW capacities in both 1&3phase power supplies. The cool/heat COP for the 11.2kW is 4/4.33 - even the 15.5kW model can do 3.29/3.72 which is better than some twin fan mini VRF's twice the physical size (more outdoor coil surface area).
This new model is only just being released in the UK and info / prices are not yet available (they are advertising it but won't / can't give us prices arrrrrrrgh). However, you can download a catalogue from the MHI Japanese website (sorry can't provide links yet). Watch out though because the file is a whopping 32meg.
Come on Daikin, Mitsi Elec, Tosh, Hitachi et all you've got some catching up to do!!!

[Greengrocer]

Hi ozairman

Do you really think ,that on VRF systems the kw can't be extended to 130 % or 150%.Do you suggest ,that it is a theory but in practice we should stick to 15.2 kw.;)

This depends on the applicacation. It's down to the system "diversity" on the VRV/F system which is the assumption that the heat load of multiple rooms on the same an A/C system do not peak at the same time. As such more rooms or connected indoor unit capacity can be handled by a smaller capacity outdoor unit.
e.g. The diversity in a 2 storey house could be as high as 200% on the basis that only the living areas need to be conditioned during the day and bedrooms at night. So instead of installing a system with a 10kW outdoor unit a 5kW will do the same job if the bedrooms and living areas indoor units are never used at the same time.
In a commercial office application diversity is a bit more tricky to calculate or assume. I've seen many a VRV/F job that's not working too well because the original designer has assummed too much diversity or, mixed rooms of dissimilar useage, orientation or internal heatload on the same 2-pipe system.
I have a job on my desk right now to quote a company to re-configure a brand new Daikin VRVIII 2-pipe system (2 off) because someone put a high density south facing IT room (30kW) on the same system as a North facing low density open plan office (15kW). The VRV system (nominal 38kW) is their only form of heating in the building. The IT suit keeps the system in cooling for 95% of the year so the the North office can't get any heating. A total miss-application and incorrect use of diversity.
It will cost this company in excess of £12k to break up the existing 2 x 2ipe system to create 4 separate systems (2 for each floor). Would have been alot cheaper to do it with splits instead of VRV in the 1st place.
I might add that for 3-pipe / heat recovery VRV systems dissimilar room loads and orientations is exactly what you do need inorder to make the system recover as much heat as possible. I've also seen these miss-applied where 3-pipe systems have been installed as a 2-pipe would be which totally negates their ability so save energy by having a heating and cooling requirements at the same time on the same system.
Oh the wonders of VRV/VRF. Sorry for the long and convoluted reply but you know how it is when your in the middle of something that suddenly pops up on RE. Here I go again. Slap wrist. I'll shut up now.

[Grizzly]

New to RE but not industry.
Do you have to use Fujitsu J series?
If not consider MHI's FDCVA140 KX4 Mini VRF system. Indoor units have EEV's fitted at standard not in pipe-work. Only snag with this outdoor unit is its the larger twin fan type and indoors are a bit agricultural to look at. However it is about to be replaced by the new KX6 which is a single fan design like the J series but far more efficient and has a 150% connection ratio.
FDCVA140 units are on special with 3D/HRP as they try to run down stock before launch on new model.

Hi Greengrocer and all the other guys from this area of Expertise.
As you may of guessed it's not my normal "zone of operation".
So please excuse me being thick!
But what does the term "150% Connection Ratio" refer to?
Thanks Grizzly

[ozairman]

Green grocer has hit it on the head about diversity, basically the outdoor unit capacity is 15.2kW cooling and 16.6kW heating
BUT
You can connect a combination of indoor units that totals up to 22.8kW (cooling) to the outdoor unit which is 150% of the outdoor unit capacity so that if all indoor units are running that 15.2kW will be spread over the entire system. If the consumer understands that they have a 15.2kW unit and can move the capacity around the house to service different area's room according to use then it is no problem. Unfortunately most tend to forget this about the day after the system is installed and on the next hot day ring up complaining that the system does not cool their house enough as they have every indoor unit on and turned down to its lowest setting. You then have to go through the process of explaining to them all over again how it was designed to work!!

Much the same as in Australia people install ducted air conditioning systems with zone control dampers in the ducting, the consumer expects they can turn every zone on and cool their whole house when in reality the air con unit was only sized to cool half their house:eek:

[Greengrocer]

Hi Greengrocer and all the other guys from this area of Expertise.
As you may of guessed it's not my normal "zone of operation".
So please excuse me being thick!
But what does the term "150% Connection Ratio" refer to?
Thanks Grizzly

Hi Grizzly. Ozairman has, to return the favour, hit the nail on the head with his reply. Obviously the time diff has allowed him to beat me to the punch. Just got back from a 10hr day in London in what is positively balmy weather. Shouldn't complain too much since I picked up £40k worth of orders - funny how as soon as the old "current bun" (sun) comes out people pick up the quote that's been on their desk for the last 6 months & want it installed next week!!
The max connection ratio's for many VRF/VRV systems are increasing which for the uninitiated can get you into some real problems. e.g. with permission from Daikin and under certain circumstances with certain types of indoor units Daikin will permit a 200% connect ratio i.e. 50kW outdoor unit with 100kW of connected indoor units. The reason so many designers gamble on the max amount of system diversity / higher connection ratio is to keep the cost down. Great for winning jobs but it can, and normally does, come back to bit you big time if the system doesn't work as "expected".

Hi Ozairman. I know all about the zoning issues you mentioned on the ducted systems. Back in the 80's I brought the Carrier VVT (Variable air Volume & Temperature) system over to the UK form the States and ran all the training courses for Carrier dealers. In those days most of the market was ducted and by zoning up multiple offices onto a cost effective packaged rooftop or ducted splits it was a lower cost alternative to a full blown VAV (Variable Air Volume system - constant supply air temp) or 4-pipe fan coil system. The corner stone of the training course was centred on system diversity whereby to make the system work the run out ducts and diffusers had to be oversized by at least 20%. In this way you could "over air" any zone to reduce the running time in either cooling or heating which then allowed the system to switch back and forth between cooling & heating without getting stuck in one or the other for too long - thereby satifying both heating and cooling demands that occured at the same time.
Well here we are 20+ years later & small capacity ducted systems using rooftops or big splits are vertually non existant now. How times have changed - of have they?