Design Help

[Bakerbj]

I have a customer that want 4 Ceiling mounted units each about 7kw heating and cooling, I ve only done single units before, can anyone recommend the best to do this. Either 4 single systems or one with one outdoor unit and 4 internal.

[winfred.dela]

For small refrigeration capacity, the simplest system is the best: 1 compressor, 1 condenser, 1 expansion device, 1 evaporator, 1 control.
The 4 compressors, 4 evaporators, 1 condenser and 4 expansion devices with 4 refrigeration system is a little complicated. The other complicated systems: one compressor with multiple evaporators is of course challenging and may not be the best for design engineers.
One advise I do not forget from an old timer when I started in this trade (more than 20 years ago) is: K.I.S.S. - Keep It Simple Stupid.
Hope to have shared something valuable.

[frank]

I have a customer that want 4 Ceiling mounted units each about 7kw heating and cooling, I ve only done single units before, can anyone recommend the best to do this. Either 4 single systems or one with one outdoor unit and 4 internal.

To do this with one outdoor unit you can either go for a VRV/VRF system of a quad split.

If you have only ever done single splits then you have either got to learn an awful lot quickly or get a more experienced tech involved.

If you are doing it yourself - better stick with single splits

[Brian_UK]

Could go with two x multi-twin sets perhaps.

[Bakerbj]

just got a quote from HRP for a VRF system, comes in £2000 more than the budget for the job !!!

[davej]

simplest way and probably will prove the cheapest is to use four individual splits and group control them!

VRV and VRF always work out ore exspensive as does the multi split option.

[winfred.dela]

VRV/VRF will be expensive for few evaporators. I only consider this when evaporators will be in hundreds.
Maybe because manufacturer's priced these equipment very expensive.
When evaporators is around 50, i suggest to the customer a chilled water system using brazed plate heat exchanger plus air cooled condensing unit (from aircon splits available locally)

[mordechai]

"simplest way and probably will prove the cheapest is to use four individual splits and group control them"

how do you group control?

[winfred.dela]

Why group control? It will be another expense which you will definitely charge to your customer.
I suppose when you supply each split has its own control.
Also, i believe your room size is not much so an individual control will just be fine.