Panasonic VRF - Maximum Allowed Capacity of Indoor Units

[Refrigerologist]

Hi Chaps,

I have recently quoted for a job that requires about 140kW of cooling. We selected equipment that would provide about 120kW as this is for a job where the premises are not fully occupied. Today we found out that a competitor has quoted and we have been asked to submit a revised quote based on a new equipment selection.

The competitor has stated that 142kW of cooling is required. The equipment that has been selected is 2No. Panasonic Model U-8MF2E8. Combined these are 16hp and will provide 45kW of capacity. The installer is proposing to install 22No fan coils with a combined capacity of 169.7kW.

Am I correct in thinking this is a mismatch as this exceeds Panasonics 50% minimum and 150% Maximum connection ration, or is there a work around that will allow this selection to operate. The idea is that each suite will not be in operation at the same time and so 2 or 3 of the 11 suites can be used simultaneously.

I have more or less been told to mind my own business, but I do not want to see a client installing equipment that cannot possibly work.

[install monkey]

The New Panasonic 3-Pipe 6N Series offers the bestto the most demanding customers.·
Maximum capacity size as 48HP by 3 units combinations (16 HPx 3 = 48 HP)· Up to 52 indoor units connectable· Maximun capacity ratio of 150%
therefore 48hp gives 150kw- but based on 150% diversity youd only need a 100kw outdoor so a 36hp gives 101kw cooling cap- only issue with going 150% diversity is if theres no radiators for extreme low ambient it may struggle- check if the building is cavity insulated- and and big ceiling voids will cause issues

[Tayters]

Have I got that right, 45kW outdoors connected to 169kW?
Seems a tad on the large side at 375%. Would need to ensure maximum pipe lengths, max ref charge not exceeded, system won't put up an error code if too much connected. I'd like to think the wholesaler has confirmed this design is fine for any warranty purposes and has also spoken to Panasonic (if they could get hold of them!)

[Panasonic-Tech]

This install would be outside the norm but will operate,

[Asbolute]

This install would be outside the norm but will operate,

Yes but would it be covered by warranty?

[Refrigerologist]

Thank you chaps, the client has confirmed that only 2No. size 16 will be installed and I understand that there is no capacity error that will stop the system from operating. What would worry me is that the oil return will be poor, but I suppose that will be taken care of in oil recovery mode, despite the lack of capacity. The idea is that as the system is installed across a number of unoccupied DR suites, then only a few of the coils will be in use at any one time. Is it possible that excess oil will be pushed into those coils not in use? With this in mind I wonder if the compressors will be operating for long periods starved of oil. The installer is providing a warranty, but if it is unreliable that isn't a lot of use 5 years down the line.

[Refrigerologist]

Have I got that right, 45kW outdoors connected to 169kW?
Seems a tad on the large side at 375%. Would need to ensure maximum pipe lengths, max ref charge not exceeded, system won't put up an error code if too much connected. I'd like to think the wholesaler has confirmed this design is fine for any warranty purposes and has also spoken to Panasonic (if they could get hold of them!)

Sorry for posting this out of turn, but yes you are correct. That is the equipment that has been quoted for. I called another Panasonic distributor and he said it is not something they or Panasonic would provide a warranty on. But, he did say if the contractor was to offer the warranty, then there is nothing to stop them installing the system as there is no capacity error fault that will prevent the system from operating.

Does anyone know what problems could occur in such a setup?

[Good^Man]

At the end of the day, the manufacturer needs to be able to give a warranty on the system/design. If you can furnish them with all the facts of the proposed install (drgs, location of equipment, and loads, etc) and they say it is outside their operating range and they will not give a warranty, that is what you can show to the customer.

(By giving project address to manufacturer, they will also understand full well what the other contractor plans to do with their equipment and pull the warranty from their quotation if they have not already. But sometimes the manufacturer supports a warranty without full knowledge of the site conditions.)

The customer wants a low outlay but s/he also wants the system to work without serious issues for at least 12yrs. If the manufacturer will not give a warranty, only a fool customer would still pay out many many £1000s to have the system installed.

It is all very well that the other contractor says he will cover the warranty for 3yrs but with small print and arguments, they could also just walk away from the thing after they are paid for the install or when the problems start showing themselves. The installer has monopoly on the service+maintain the system afterwards by virtue of their warranty and their prices can rocket with no competitor. And customer is held to ransom. The customer will be the one stuck with a brown fan.

From your side, if the customer still wants that particular system installed, you could offer to install it at a lower price but carefully make it clear that you cannot offer any equipment warranty on the system/design, just the pipe/cable installation

Sometimes you have to step back and walk away.
Sometimes you wind up with more income by staying at home watching TV.