What we learned about air conditioning in the Philippines when we built our own Philippine house. As readers know, we’ve tried to do everything we can to design and build our house to minimize the need for air conditioning in our new Philippine house. Much of Panay Island’s power comes from coal burning power plants. Electric power rates are high, about $.27(US) per kilowatt hour now (2013) and rising. So, there are at least two reasons to feel uncomfortable about unnecessarily using electric power.
Few foreigners who live in the Philippines live in such a quiet rural place as we do. A major attraction of air conditioning, besides keeping cool, is that it is just about the only way to reduce or escape noise and pollution. A good night’s sleep may be only a dream in the face of roosters, loud music, karaoke and roaring jeepneys. Even if it’s not so hot, as every hotel guest knows, the impulse to close the windows to the noise and be lulled asleep by the white noise of the air conditioner can be irresistible.
So, while we have roof insulation, big windows and a breezy location, there are often times when air conditioning is wanted, especially when music from local fiestas booms and during the hot summer season when daytime temperatures reach 37C (97F), humidity is high and nighttime temperatures don’t fall that much. No matter how well designed, any house can be uncomfortable and a relief from the heat is a relief worth paying for, especially older and less healthy retirees. For us, air conditioning is also a courtesy to guests not accustomed to the tropical heat. We have a dear friend who suffers from emphysema. Our guest room air con is specially for him.
In our first Iloilo apartment we had a regular window-type air conditioner in each bedroom. In our next (and last) apartment we had modern Panasonic split type air conditioning throughout. That convinced us that we wanted the split type units. Split air con units have the compressor outside in a separate unit. This is connected to the unobtrusive interior unit which contains the evaporator, fan and controls.
Basic split units cost about one-third more than basic window units. For example,a basic Panasonic one HP window unit costs P14,899. A basic Panasonic one HP split unit costs P22,999. According to Panasonic, they are of about equal efficiency. A more efficient one HP inverter unit (more on that later) costs P29,999 or just twice as much as a window unit. The split units are much quieter, more civilized than the window units. Also they may be a bit more secure as the split units only require a small hole in the wall whereas window units installed through the wall require a substantial opening. If your unit has to go in for repair, you can be left with a new entrance to your residence!
An advantage to conventional window or through-the-wall units is that they may be removed for a thorough inspection, cleaning, power washing and maintenance. Split units generally must be cleaned in place. That can be messy. Think of your unit being power washed inside your bedroom! The pan catches most of the spray which is routed outside by means of a hose. We have had good luck with the crews sent by Samsung to maintain our split units. They have been careful. Still, easy repair and maintenance is a plus for through the wall units.
When you buy a split air con unit you’ll have to decide between the more expensive, more efficient inverter units and the regular units. Regular units have a compressor which turns on and off as needed to cool the room. Inverter units have a compressor which runs more continuously, but can vary its speed and power consumption to maintain room temperature. Under ideal circumstances, the inverter units are more efficient. If you buy an inverter unit, make sure it has adequate or excess capacity for the space. The inverter unit can silently and efficiently reduce its speed and continue the dehumidification function. For example the Panasonic CS-PS12KKQ specifications claim that the unit can adjust its output from 14,400 kJ/hr to 3,060 kJ/hr and its electrical consumption from 175 to 1180 watts. The nominal rating is 820 watts.
Inverter pioneer Daikin has a good description of the advantages of inverter units Japanese Daikin are considered the Cadillac of air conditioners.
If you buy a standard unit, it’s better for it to be somewhat undersized so that the compressor can run more or less continuously. Motors use two or three times as much power starting up as they do running. Standard units are more efficient that way (possibly more efficient than an inverter unit) and they keep dehumidifying. The worst thing is a too big standard unit which cools the room off but does not run enough to dehumidify the air. You end up with cold, clammy air. Don’t let air con salespersons talk you into a too big conventional unit. Do your own calculations and take into account just how cool you want your room to be. Conversely, don’t buy a too small inverter unit. Running continuously at peak output, they may be less efficient than a cheaper conventional unit.
Air conditioner efficiency is roughly rated through EER – the energy efficiency rating. EER is calculated by dividing the cooling capacity in kJ /hr by the power used in watts. Keep in mind that the lower power consumption of the inverter units can be accompanied by lower absolute cooling power. For example, a conventional 1.5 HP Panasonic has a cooling power of 12,740 kJ/hr whereas an inverter unit has quite a bit less capacity at 11,020 kJ/hr. This means that not only are the inverter units more expensive, but you may have to buy the next bigger inverter unit to get the same cooling capacity as the smaller but more powerful conventional unit. No wonder the manufacturers spend so much time touting their inverter units.
We decided to buy a inverter unit for our “master’s” bedroom and a conventional unit for our guest room. No air conditioning is be installed for the rest of the house, at least for now. We used an online calculator to determine the size of the unit we needed. Here’s a good general discussion of sizing air conditioning units: http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/95/950509.html
If understanding the difference between kWh, HP, kJh, and Btu is confusing, check out the following site. After you calculate your cooling needs using the FairAir calculator above, fire-up this Power Converter site and plug in your cooling need and then you’ll get it automatically converted to all of these measurements and dozens more.
This calculator concluded we needed a 3.5KW unit for our 25 square meter bedroom. Since 1KW equals 3,412 BTU, we needed a 11,942 BTU unit. Since Philippine air con units are rated in kilo Joules per hour and since 1 BTU = 1.055 kilo Joules, we needed a 12,600 kJ/hr unit.
TIP Air conditioner sales persons are notorious for selling higher capacity units than the customer really needs. They get to sell a bigger unit but more importantly, they’ll never have a customer come back and complaining about not being cool enough.
Initially, we intended to buy Panasonic units, however when we checked the specification for a Panasonic 1.5HP inverter unit we saw that it was rated at 11,630 kJ/hr. Shopping around we saw that the 1.5 HP Samsung inverter unit was rated at 13,650 kJ/hr, substantially more than the Panasonic unit. In addition, the Samsung was about P3,000 cheaper. Since we have had very good luck with our Samsung washer, we decided to go with the Samsung. We bought two units for a package deal, the 1.5 HP inverter for our bedroom and a standard 1 HP split unit for the guest bedroom.
The purchase price included free installation by the Iloilo Samsung service center (033-508-3810 mobile: 0917-323-4818) and free cleaning and maintenance for the first year or more.
Installation crew foreman Dante F. Montalban arrived with his crew. I am very fussy about work on our house so I watched them like a hawk. I was very pleasantly surprised at how careful and competent they were. They arrived in a truck with the tools and materials they needed. It took the better part of a day for the three man crew to install the two units. The 1 1/2HP inverter unit was made in Thailand, which seems to be an Asian hub for the manufacture of refrigeration equipment. The 1 HP conventional unit was made in China. The Chinese-made unit seemed very well designed and built. The outdoor compressor/fan cabinet is made of plastic, nicely done. This can be an advantage because steel cabinets rust, especially if you’re anywhere near the ocean. I asked about repair experiences and he said he had had to replace circuit boards on the inverter units because lizards make nests and short-out the circuits. He said this is not a problem with conventional units. Generally there is more complexity and more to go wrong with inverter units. Unfortunatley, he was correct about the lizard problem. See below.
The outdoor part of the split air con can rest on a concrete pad on the ground or can be bolted to a bracket bolted to the outside of the house. We had our welders make the brackets while they were building our house, using scrap angle bar. The brackets are attached to the wall using lead expansion anchors and lag screws.
I installed the electrical circuits and wiring. Each unit has its own 15 amp circuit and breaker. Wiring is 12AWG (3.5mm). I am sure the installers would have done the wiring but I wanted to do it myself.
Above you can see the connections between the indoor and outdoor units; two insulated copper refrigerant lines, a drain line and power line.
Each of these rooms also has a Hunter ceiling fan. Ceiling fans are much cheaper to run than air conditioners and even when the air con is on, keep the ceiling fans running. That way you’ll be comfortable using less air conditioning.
Cost of air conditioning. With no air conditioning, we consistently used about 300 KWH per month which costs us about P3,600 ($85) per month. When we used the split air con units at our apartment, we were surprised at how little they cost to run. That because we generally set the desired temperature at 27C. Supposedly each degree of additional cooling adds about 15% to the power consumed so setting the thermostat at 24C would cost 60% more than a 28C setting. When you size your unit, keep your cooling preferences in mind. During the hottest weather when we use our master bedroom split air conditioner every night (and the second uit occasionally) our total electric bill will rise to about 400 KWH or about P4,800 ($112). This suggests that it costs us about $1.00 per night to air condition our large bedroom. We attribute this low cost to the efficiency of our inverter unit and the fact that we set the thermostat to make the room comfortable rather than cool or cold.
Recall that we bought the Samsung aircon unit rather than Panasonic because the Samsung specifications said that they were more powerful than the Panasonic units. We were unhappy to find that the Samsung inverter unit which was actually installed for us was NOT rated at the 13,650 kJ/hr capacity Our unit’s label gives a rating of 11,630 kJ/hr. AFTER we bought our unit the Samsung website was revised to show the cooling capacity of the 1.5 HP ASV12ESLN as 11,630 kJ/hr rather than 13,650 kJ/hr that was listed when we bought our unit.
We are fairly happy with the small Samsung conventional unit but less so with the Samsung inverter unit we bought. Samsung advertises that the units are compact but that seems to mean that the fins on the inner evaporator and outer condenser units are packed close together. To us it seems that the fins are more easily damaged and clogged with debris and may require more maintenance. Our one-HP Samsung unit seems better in the regard. The fins have a blue coating which seems to be resisting corrosion better than the tightly packed fins on our Samsung converter unit.
Also, after three years, the Samsung inverter is showing signs of less than stellar material quality. The case screw and bolt heads are rusty, the case itself is also starting to rust. The Chinese made non-inverter unit seems better made.
Cleaning and maintenance. Initially we were happy with the periodic maintenance provided by Samsung. Then one day we bought a shop vac and we decided to use the vacuum on Samsung unit in our bedroom. Closer examination revealed that the long squirrel cage fan which expels the cooled air was almost totally clogged with caked on dirt. Obviously it had never been cleaned by the pressure washer the Samsung maintenance crew used. We had to partially disassemble the indoor unit to be able to clean the clogged vanes of the fan. The same was true of the exterior units. The casing had never been removed during the cleanings done by Samsung. We decided to remove the cases and found that while the electronics seemed to be in good shape the unit was quite dirty with lizard droppings and wasp nests. While the Samsung cleaning service is a reasonable is P800, we have decided to buy a pressure washer and doing our own cleaning.
As predicted, a lizard crawled into our Samsung inverter unit and shorted out the main circuit board. Inverter units have more complex electronics. Our repairman said that this is a very common problem with Samsung inverter units. Why don’t they improve the design? We have to wonder whether the money saved through lower power consumption of an inverter unit ends up being spent on more repairs for these finicky units.