my house is single phase.

Living room = 2.5HP inverter
Master bed room = 2.0HP inverter
Backroom 1 = 1.5HP inverter
backroom 2 = 1.0 HP non-inverter

Do you think is OK still if i install 2.0HP at first floor living room and 1.0HP at ground room?

Will burn or not the db box?

i thought the rule was < 4HP for single-phase?

anyway, additional input - most people also takes into consideration
of other loads (e.g. cooking hob, cooking hood, fridge, dishwasher, water pump, etc.)
which would also affect the max. HP/load for the DB.

Har? Dun scare me, that day the aircon installer summore ON all 1.5HP + 2.0HP + 2.5HP + 1.0 HP (Total 7 HP) all together...

In before I start digging in this 60pages of thread, anyone can highlight me how to pick/choose air-cons by using formula or method, and pros and cons.

Need to buy air-con end of this months, need do some research in before chop by salesman.

As long as the total meets the 60Amp requirement

I am using single phase, I have total of 6 A/Cs, with total power of 8HP. I have try switch on all for 1 hour plus without issue. I even have two storage heater.

If you intend to switch all on, and continues run for many hours get a 3 Phases, if not a single phase will do.

u means u ON all aircon in less than 1 minute (ON living room one then go up stair on all rooms one etc)?
Or u ON 1 aircon, after 10mins then u ON second one... then eventually all RUN together for 1.5 hour after 1 hour u switch ON all of them?

This post has been edited by sovietmah: Jul 7 2014, 02:29 PM

Cannot on all in 1 min la, I don't have universal remote to switch on all at same time. I switch it on in sequence, all in about 2 mins. I was doing load testing see how long it can handle before the fuse trip. Even try switch on one water heater. That around 10kWatt in total.

Sounds like can tahan 8 HP + 2 storage heater.

8HP + 2 Storage maybe overloading. but 8HP + 1 Storage is good enough. I seldom switch on all 6 AC same time, wallet cannot handle the burning

Inverter for bedrooms or any space that consistently requires greater than 6hours of cooling. Non-inverter for any short or spot use cooling for short duration (1-4 hours).

Heat load determination = L x W x hlf= Area (in sq ft) x hlf = heat load in British Thermal Unit (BTU)
Use the resultant BTU calculated to determine what AC horsepower to get.
hlf depends on room orientation, if there's external shading over room, if insulation is present.

Base conservative head load factor (hlf) typically is:
60 for condos and ground floor
70 for upper floors beneath uninsulated roof
75 for top unit of condo/apartment.

All this assumes 10' ceiling height. If ceiling is low like 8-9' then -5 from the base.
If ceiling is higher than 10' but less than 15' then add 5 to the base.
Mostly the base numbers are constant assuming that 4" thick clay masonry bricks are used for construction.
8" thick clay masonry bricks can -5 as there's more thermal mass it can contain. These type of bricks tend to make the house feel cooler.
AAC has thermal insulation advantage that allows 50-75% the base of the heat load factor of 4" masonry brick.

HLF Modifiers (+/- to base hlf):
+5 if sun facing area is W,SW or S and has larger than usual fenestration (windows)
+10 if room wall faces W,SW or S (typical corner unit)
-5 for shading or roof envelop insulation
-10 Mostly shaded (facing high mountain directly behind with lots of high trees or just behind is jungle or another overly tall building)

Take a typical north/northeast facing DSH intermediate with gross build up of 22x70 ground floor living room (20'x20') and first floor MBR (12'x15')
Assuming dining and living is zoned w AC
Living room = 20'x20'x60=24000BTU.
Upper floor MBR with uninsulated concrete tiled roof = 12'x15'x70=12600 BTU

Look up any AC spec will reveal that a living room and MBR of the above size requires 2.5HP AC and 1.5HP (BTU at upper limit of typical 1.5HP of 12,000-13,500BTU). If in doubt, try turning the MBR in the day time at AUTO mode and see how long before temp reaches pre-set and compressor idles again. Modern 1.5HP AC esp w inverter would have power mode that strecthes from 12,000 to 14,000BTU depending on make and model.

Again the numbers are a rough guide. Cooling is acheived faster when the heat load is low esp during raining but the stored heat from the roof and walls will radiate inwards until 3-4am when everything is cooler like outdoor again but the trapped heat unless dissipated may still cause the inside to feel hot without AC cooling.

This post has been edited by halcyon27: Jul 7 2014, 08:01 PM

halcyon27 TQ for the wall of text. Well, I do read every single text wrote above. Thanks! Now I go measure the place first.

helo all

found this from lazada,

Sharp 2.0HP STANDARD Air Conditioner AHA18PCV-RM1,799
Sharp ( PLASMACLUSTER) 2.0HP Air Cond AHAP18MMV-RM1,999
Sharp (INVERTER ) 2.0HP Air Cond AHX 18 MEV-RM2,199

Are these deal gooding? Got better price elsewhere?...

I planned to get a power socket for my aircon...

as info from my air con guy, he strongly recommended to use BS546 (round shape) power socket for any a/c more than 2hp instead of the common 3 pin power socket BS 1363... Can i use the common 3 pin power socket for 2.5 hp as power consumption below?

As checked from my catalog, the maximum power consumption about 2130watt (9.4A)
also checked from the label of the compressor, the maximum input about 2.52kW/11.1A

Why do you need a socket for A/C? extra contact points mean extra problem. Get a 20Amp on/off switch is better.

I had a on/off switch for the air con

i planned to hook up with lightning protector which come with the standard of 3pin power socket, that why i reserved a socket right beside the air con indoor units... just wondering still a good idea to use common 3 pin power socket for 2130watt...

nope. that's nearly continuous 10A of current. short surges will peak more than that. if you have voltage sag then the current will also increase.

hospital/medical grade socket/plug might be able to withstand, but it's awfully close to the maximum rating. i'd rather not risk it.

Can check in hardware shop for 13A socket

Well...aft pages of reading..for inverter n non inverter...
Inverter=save when switch on for more period of time,6hr or more...

Non inverter=for a shorter time less than 4,5 hr...

But all must be based on the space size to get better cooling...

If possible try to get econavi feature,
I noticed that the econavi help me save lot of money on my tnb bill.
it will auto adjust the temperature celcius when no ppl inside the room (eg: u on aircon but u went to kitchen or bathroom for a while), and as well as when you are sleeping (no movement).

17x10 ft room i ON the 2.0HP inverter aircon 11PM->7AM 25C speed 3/5, only use up to 4KW of electricity for this period (include other stuff like 600L inverter fridge, 24/7 water boiler, autogate / alarm system / 3 cctv and about 40W lighting.

This post has been edited by sovietmah: Jul 11 2014, 09:40 AM