Electronics & Appliances AC or heat pump?

I'm knowledgable enough to be dangerous and primarily familiar from what is available in the US, so looking to understand what's available in the Philippines around cooling. Looking at getting a mini-split AC system for my place in Dumaguete. I'm looking for a 3 zone system. It seems if you get just an AC, you have 1 zone or 2 zone options. Looking at heat pumps in the US you have have up to 5 or 6 zones, but these are heat pumps. I realize that needing to heat the house would be rare, but if the only way to get more zones is to go with a heat pump, that might be necessary. Anyone installed an AC mini-split system with more than 2 zones? What did you buy to do it? Recommendations? Thanks.

 

@cabb
Daikin makes a 3 zone system for home use.
https://www.daikin.com.ph/products/room-air/multi-split-type/

No experience with heat pumps at all. No experience with multi zone systems.
My place has two Daikin inverter/split type air conditioners.
My experience with Polaris has always been good and they actually had the part in stock for a repair I needed.
At some point I expect spare parts may not be available so I'll be able to scavenge spare parts from one of the units when it eventually fails. You might want to consider that strategy.

Slightly off topic but; I had a two year old Samsung washing machine which blew its control board. "Sorry sir no spare parts no longer in production". The repair tech p!ssed me off "sir since your washing machine looks brand new we can negotiate a partial refund from Samsung for you". We declined as the offer sounded shady. Two weeks later the tech called to announce he had found the required control board.
Anyway spare parts here is a concern and having 3 identical units is the strategy I would consider.

 

Adding A/C to our place in Bacong is something we will do after we retire, when we get to spend more than a few weeks vacation time there. I'm leaning towards a single zone split unit for each room we choose to cool. If one fails, move my pillow to one of the other rooms whilst the failed unit is getting repaired or replaced on Philippine time.

For those of us dangerous enough to know. What makes a split unit a heat pump is heat pumps can reverse the refrigerant flow which allows the condenser and evaporator to switch rolls. Eliminating the cost of the reversing valve and its controls in units sold in tropical climates makes sense.

 

The AC guy in the Philippines has been talking about AC in HP from a sizing standpoint. We usually talk tons or BTU/hr of cooling and/or heating capacity. Is this a metric/standard units thing?

 

Good question. My A/C experience, like you, is in the US, so tons and Btu/h. I think Btu was created before GB adopted the metric system as Pounds and Fahrenheit are not metric.
1 Btu is the amount of heat required to raise the temperature of 1 pound of water one degree Fahrenheit.

Tons and HP are both units of measure to classify power or energy. Heat is a form of energy so both work in that regard. That said, googling sizing charts for mini splits will show Btu and tons. HP might be out there, I didn't find it. You might have to covert Btu/h or tons to HP first.
https://www.kylesconverter.com/power/btus-per-hour-to-horsepower
https://www.kylesconverter.com/power/tons-of-air-conditioning-to-horsepower


For the curious, an explanation of tons as it pertains to A/C: https://www.energyvanguard.com/blog/why-is-air-conditioner-capacity-measured-in-tons/

 

1 HP = 9000 BTU/hr = 0.7457 kW

 

1HP equaling 9000BTU/hr sounds kind of high to me. On the internet I am seeing 1HP = 2544BTU/hr, so 3.53HP = 9000BTU/hr

 

The plot thickens. This chart indicates that 1 Ton = 12000 BTU = 1 HP.

https://www.generatorjoe.net/html/ACLoad.html

Here is another chart that shows what I think is the correct conversion and how each is defined.

Ton of refrigeration
Definition: A ton of refrigeration (TR) is a unit of power. It is defined as the power required to melt or freeze 2000 pounds, also known as one short ton, of ice per day. The ton is more often a unit of mass. A ton of refrigeration is approximately equal to 12,000 BTU/h or 3.5 kW.

History/origin: The ton of refrigeration originated around the 1880s during the transition from stored natural ice to mechanical refrigeration. It became an industry standard in 1903 when Thomas Shipley pushed for the formation of an industry association as well as for standardization of a number of equipment specifications. This eventually led to the founding of the American Society of Refrigerating Engineers in 1904.

Current use: The ton of refrigeration is mostly used in North America, specifically within the context of refrigeration and air conditioning equipment. It is often displayed alongside BTU/h specifications.

Horsepower (metric)
Definition: The unit horsepower (symbol: hp) is a unit of measurement of power (the rate at which work is done). Mechanical horsepower, also known as imperial horsepower, is defined as approximately 745.7 watts (550 ft·lbf/s), while metric horsepower is approximately 735.5 watts (75 kgf·m/s). Boiler horsepower, albeit a less common measurement than either imperial or metric horsepower, is used for rating steam boilers, and is equivalent to 34.5 pounds of water evaporated per hour at 212 degrees Fahrenheit, or 9809.5 watts. In addition, when rating electric motors, one horsepower is equal to 746 watts.

History/origin: The term horsepower was adopted in the late 18th century by James Watt to compare the output of steam engines with the power of draft horses. Watt was not the first person to compare the output of horses to that of engines. As early as 1702, Thomas Savery referenced horses when describing the output of an engine. It is believed that Watt built on this idea and introduced the term horsepower, largely in an effort to market his steam engine. The term was later expanded to include other types of output power such as the imperial and metric horsepower measurements commonly used today.



Ton (refrigeration) to Horsepower (metric) Conversion Table
Ton (refrigeration) Horsepower (metric)
0.01 ton (refrigeration) 0.0478158915 horsepower (metric)
0.1 ton (refrigeration) 0.4781589149 horsepower (metric)
1 ton (refrigeration) 4.781589149 horsepower (metric)
2 ton (refrigeration) 9.5631782979 horsepower (metric)
3 ton (refrigeration) 14.3447674469 horsepower (metric)
5 ton (refrigeration) 23.9079457448 horsepower (metric)
10 ton (refrigeration) 47.8158914895 horsepower (metric)
20 ton (refrigeration) 95.631782979 horsepower (metric)
50 ton (refrigeration) 239.0794574475 horsepower (metric)
100 ton (refrigeration) 478.1589148951 horsepower (metric)
1000 ton (refrigeration) 4781.5891489505 horsepower (metric)

 

This might be helpful.
https://101appliance.com/how-to-find-the-proper-aircon-capacity-for-your-room-size/

Room Size Capacity (kJ/hr) Estimated HP Rating
≤ 10 sqm. 5,000 0.5 HP
10 - 15 sqm. 5,000 - 7,500 0.75 HP
15 - 19 sqm. 7,500 - 9,500 1.0 HP
19 - 25 sqm. 9,500 - 12,500 1.5 HP
25 - 35 sqm. 12,500 - 17,500 2.0 HP
35 - 43 sqm. 17,500 - 21,500 2.5 HP

From the article, "Aside from kJ/hr and BTU, an aircon’s capacity can also be measured in horsepower (HP). However, HP is used to measure the motor’s power, not the aircon’s cooling capacity. That is to say. different models with the same horsepower rating may differ in their cooling capacity."

After pondering this I'm thinking that HP is not the best way to describe cooling capacity.
Not all motors are equally efficient. 1hp 110v motors are normally less efficient than 1hp 220v motors. Sorry, I'm using the US voltages I'm familiar with. Both can create 1 HP of mechanical force but 220v will use less current to do so, making it more efficient. That is not entirely why I think this though.
Thinking back to when the US auto industry switched from R12 to R134a, the condenser and evaporator increased in size, the compressor pressure output increased. The r134a compressor takes more HP to operate than the r12 compressor did, to achieve the same cooling capacity.

 

Sorry Del I gave this a funny rating, this is not just funny to me it is Fecking hilarious, but I guess I am on my own here? reading this and the comments it raises has made my day.

I know I must sound like a smug Bar Steward and I'm holding up my hand here admitting it, but you must realise I built an insulated house there with an added cool roof and NO AC required, I must admit it does come with its share of problems? the saving to be had not having AC (the cost of installation, running costs and quite high maintenance costs I believe?) give me a much higher disposable income, so I have to spend so much time in Bars to get rid of it all and have become a Drunken Master, however when I get up in the morning I know my day can only get better once the drink wears off.