if you have the budget, go hitachi.
as claimed by the shop owner who recently installed my samsung a/c inverter, the lowest power consumption brand in the market is hitachi.
he showed me one table pointing his fingers on the running amps of different brands. hitachi seems the lowest of them all.
In AC (alternating-current) systems, lower amp readings doesn't necessarily mean lower power consumption. In fact, that's how peddlers of plug-in "power savers" fool unsuspecting customers. The real indication of power consumption is the Wattage it's pulling. The Meralco meters measures kWh, which although is derived from V and A, but it also consider the power factor.
On DC circuits, the Power formula is a simple V x A = W
On AC circuits, it's a bit different: V x A x PF = W
The formula VA=W on AC circuits is only true for purely resistive loads (ie. Heater, incandescent bulbs, etc.) due to it's PF being equal to "1". But for everything else, the PF is typically between 0.6 to 0.9.
So, just reading off the amps with the PF unknown, you won't be able to determine the actual power consumption.
totally agree with you on your point... but if you're comparing AC to AC or DC to DC across all brands, with the least running amps it may translate to lowest power consumption.
to be fair to the guy, he's a contractor that installs all types of aircon brands available in the local market. his business is not only confined to stand alone aircon units but also doing centralized HVAC system.
Just saying that the operating current alone does not directly translate to the real power consumed. Again, this is a trick used by unscrupulous people to sell you gadgets that promises lower electricity bills.
I agree on the energy efficiency label.
My qualm is about relying on voltage and operating current alone on an AC circuit as basis for power consumption. I did not suggest people start owning PF meters (even if I do). I brought that up to answer in anticipation the "Why not just VA?" follow-up question.
Btw, is the "0.13" value the PF you assign to inverter A/Cs in general?
Wow, very technical for me. Can you suggest just what to get for a 37.8sqm shop. Will be operating 9am-7pm every day. Will it be 2 units of 1.5hp or 2 units of 1hp?
Choices are full dc inverter units: Kolin, Hitachi or Daikin. Pls help! Thanks. Budget is flexible. I am after the longevity of the unit, cost of maintenance (is it 1.2k per 6 months for all?), and overall savings in my meralco bill.
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I've heard of this rule of thumb for basic power requirements for air conditioning system,
"One hp for every 15 square meters"
This of course does not apply if the height of the ceiling is beyond the usual standard. For example, you have a mezzanine and that means you have greater volume of air to cool down.
Following this rule of thumb, you get the 1.5 hp. Let's wait for the advice of the experts here.
What kind of shop are you running?
You have to compute for heat sources such as appliances, computers, refs etc. Then how many people will be occupying the shop, then ceiling height, then is it in direct sunlight with the windows?
Simple calculation using koppel’s site says 2.29HP for residential purposes:
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mitsubishi is also good. installed one in our branches
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Haier, Sanyo na split type AC ko 5 years na ok pa naman cleaning lang pag medyo mahina na ang buga yung Panasonic ko isang taon pa lang, yung Everest ok pa din 2 years na pero hindi siya ganun kalamig sa tatlong unit ko. Da best pa rin window type.