VRF Running Costs

[ACEngineer700]

Hello,

Can anyone help me with working out running costs for a VRF/VRV system? Any calculations would be a great help.

Thanks

[frank]

Sure........

Just post some details to allow some calcs to be done, such as:

Outdoor running amps
total indoor running amps
total daily operating hours - indoor and outdoor
price of energy paid
number of days system running per year


etc..

[ACEngineer700]

Normally I would use the calculation (Power Input x Hours per Annum) x £0.10 as electricity costs, for both indoors and outdoor units. By doing this I have come up with some very high results. fficeffice" /><O:p></O:p>
<O:p> </O:p>
Outdoor running amps = Total current 15.6A or Power input
Total indoor running amps = Current at 0.16A or Power Input at 32.6W x 10
Total daily operating hours - indoor and outdoor = 8 hours
Price of energy paid = £0.10
Number of days system running per year = Call it one day for now.<O:p></O:p>
<O:p> </O:p>
Would you factor in for the fact that the system will not be running at full power all day?<O:p></O:p>

[yinmorrison]

Either that or talk to one of the suppliers, Daikin,Mitsi etc who will usually do it quite quickly for you if there is a good possibility of a sale!

[frank]

So, for 1 day

Indoor unit: 10 No.
Assuming that the units are on single phase:

((0.16A x 10 x 240v)/1000) x 8 hrs x £0.10 = £0.31

Outdoor Unit: 1 No.
Assuming that the unit is on 3 phase 415v:

((15.6A x 1 x 720)/1000) x (8hrs x 0.75) x £0.10 = £6.74

The 0.75 assumes that the outdoor compressor only runs for 6 out of the 8 hours.

Now, if the compressor is inverter driven you will have to either apply a factor or work out an average amp draw and substitute that figure in place of the full load current.

[Thermatech]

A basic concept of VRF is heat recovery potential.
3 pipe systems & ME City Multi R2.
So if some units are in cooling & some in heating the system provides direct heat transfer from the units cooling to the units heating.

Do you want to factor this energy recovery into you running cost estimate ?

[ACEngineer700]

The reason for my delayed reply is that I have been on holiday….<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
<o:p> </o:p>
Thanks for all you help its been a great help.<o:p></o:p>

[NZPRO]

No Body head of PPD Power proportional Distribution

[abbasi]

Simple power calculation formulae
P(kilo Watt)=I(ampere)XV(volts)/1000
and multiply above by 1.732 that is square root of 3 in case of 3 phase.

I would be obliged if someone can send me comparison of 10 ton system on
1. Air cooled chiller with boiler in winter with FCU as indoor.
2.Multi digital VRF system based on scroll system.
3. conventional wall mounted split system.

I need above three comparisons with initial/running and payback costs.