Solar-Assisted Air-Conditioning In Thailand

[InterestedObserver]

Basically, I have a 15 amp, 3 phase supply to 'play' with.

Can I state the obvious, 10kVA is not much of a supply for your project. Have you made a maximum demand calculation yet?

Edited October 16, 2011 by InterestedObserver

[EvilDrSomkid]

I am interested in this concept, too. 12k for a retro fit is about the same price as a cheap AC unit. but a 60% reduction of power sounds almost too good to be true. Gil at Pool Doctors uses solar thermal panels for regulating the pool water temperatures. Heating and cooling.

i compare the 60% reduction claim with the claims of various whitening creams sold in Thailand

solar panels to raise or reduce pool temperature have nothing to do with the principle "solar assisted airconditioning". when you want to heat your pool you run your pool water through the panels when the sun shines and to cool down your pool you do that at night, early morning or when it rains.

Naam, I realize the one has little to do with the other. I also think that a 60% reduction in power consumption is ...erm... optimistic. However, I wonder if there is a power saving, how much it is in the real world. Considering the solar assisted AC needs sunlight, then it would be useless for us. We only use AC when sleeping. The office AC would be different, of course

As for OPs power limitation, 15Amp 3 phase is very little. It is barely enough for a house.

Regarding hard start AC, get the inverter types and you will avoid this. The inverter types ramp up smoothly. Depending on the size of the rooms, limit the size to 13k BTU and it should be OK.

Looking at the wider picture and considering the floods lately, an off-grid solar powered system is still on my mind, but will leave that discussion to the other thread dedicated to that. I know your feelings on this, Naam.

Edited October 16, 2011 by EvilDrSomkid

[simon43]

15 amp, 3-phase supply means that it's rated up to 45 amps per phase. It's the way the electricity office quotes it..

@Garrfeild - choosing 'green' options need not cost any more than conventional options, and can save on operating costs. My solar lights cost less than conventional lights of a similar candle power, and there are no electricity operating costs.

My greywater/rainwater collection/reuse system merely requires the installation of some cheap piping and valves - nothing more.

My solar water heaters are proven technology, more expensive than instant shower heaters, but a very small fraction of my budget.

I have to install air-con units in any case, so a slight increase in these costs to obtain a unit which has a low hard-start current surge and low operating costs seems a realistic choice, if it's truly available - don't you think?

Wind power is not viable for either of my project locations.

Passing trade? I'll refer you to my posts on the TD forum which covers that subject.

There is already the 3 phase supply right at both project locations and I have already paid and got this connected up for my workers to use at one of the sites - my discussions were about making the most efficient use of this existing supply.

@EvilDrSomKid

Considering the solar assisted AC needs sunlight...

My understanding of these solar-assisted air-con systems is that whilst sunlight is required to superheat the condensor liquid, this remains at a superheated temperature for more than 24 hours, thus ensuring that the units operate efficiently at night.

But all this needs to be checked and confirmed - as well as price, reliability etc. The obvious fallback solution is to go with inverter air-cons

Simon

[Naam]

Basically, I have a 15 amp, 3 phase supply to 'play' with.

Can I state the obvious, 10kVA is not much of a supply for your project. Have you made a maximum demand calculation yet?

please explain how 3x15amp / triple max load in Thailand (total 135amp) = 10kVA?

[Naam]

My understanding of these solar-assisted air-con systems is that whilst sunlight is required to superheat the condensor liquid, this remains at a superheated temperature for more than 24 hours, thus ensuring that the units operate efficiently at night.

there... there... Simon, no way! the refrigerant is superheated to built up pressure thus aiding the compressor in its pumping function. during idle time that pressure would dissipate except if arrested with expensive valves on both entry and exit side of the "super-heater". but even if the latter did it exist any "superheat" would turn into "average cool" after only a few cooling cycles lasting not more than a couple of minutes.

summary: no sunshine = no solar aided cooling :jap:

[simon43]

summary: no sunshine = no solar aided cooling :jap:

Indeed, and my ignorance in this area is why I need to see the unit in operation. But I'm not rejecting this or similar products solely based on analysis of their marketing documentation

Simon

[InterestedObserver]

Basically, I have a 15 amp, 3 phase supply to 'play' with.

Can I state the obvious, 10kVA is not much of a supply for your project. Have you made a maximum demand calculation yet?

please explain how 3x15amp / triple max load in Thailand (total 135amp) = 10kVA?

Simon stated that he had 15 amps per phase supply to 'play' with. If he really meant 45 amps per phase then he should have said so. Now he has 30kVA but with no overload (surge) capacity as the meter is already maxed out.

[simon43]

Simon stated that he had 15 amps per phase supply to 'play' with. If he really meant 45 amps per phase then he should have said so

I said that I had a 15A, 3 phase supply. In Thai electricity company parlance, that means a supply of between 15-45 amps per phase. The provision of 45 amps is not guaranteed 24/7, which is why it's prudent to minimise total current demand.

Simon

[electau]

I understand your problem.

You do not have much of a choice. What is your proposed max demand in amps?

1. Upgrade at your expense for a HV supply and transformer on your property, proposed distance about 400meters.

Estimated cost 1000000THB.

2. Install a diesel or LPG fueled generator and connect your load as essential and non essential load. The generator supplies the essential load only. The non essential load is taken from the existing 220/380V supply. You can run your generator ar peak periods.

3. All HW systems solar thermal.( which you propose).

4. Inverter airconditioners, one small unit to each room.

What ever way you go cost is the factor which will determine which way you go.

Other alternative sources of supply, solar PV panels and wind generation are not ecomomically viable.

　

　

Edited October 18, 2011 by electau

[electau]

Simon stated that he had 15 amps per phase supply to 'play' with. If he really meant 45 amps per phase then he should have said so

I said that I had a 15A, 3 phase supply. In Thai electricity company parlance, that means a supply of between 15-45 amps per phase. The provision of 45 amps is not guaranteed 24/7, which is why it's prudent to minimise total current demand.

Simon

The PEA cannot guarantee to supply a max demand or peak load of 45A per phase, you have a 3 phase 4 wire supply and the loads are 220V single phase balanced across three phases to neutral.

If you connect a generator you can increase the peak load. There would be NO parallelling of the PEA supply and your proposed generator.

Again the main factor is cost.

[electau]

A generator able to supply 30kW at 220 / 380V 50Hz. might solve your problems.

[simon43]

A generator able to supply 30kW at 220 / 380V 50Hz. might solve your problems.

I think that might make more noise than the nearby planes ...

Simon

[Khun Jean]

If you can find a good supply of ice you can use that to minimize electricity use.

An "ice-powered" airconditioning consists of very low tech equipment like an heatexchanger, small pump and a fan.

These will consume very little electricity.

Ice can be made in large quantities in factories for very low prices, this is very common as ice is a product that is used in markets, restaurants all over Thailand.

You can even make your own with PV , wind or methane made through an anaerobic process.

You can 'load shift' or use your normal electricity connection in non-peak hours to store its energy in ice.

Edited October 18, 2011 by Khun Jean

[Naam]

A generator able to supply 30kW at 220 / 380V 50Hz. might solve your problems.

I think that might make more noise than the nearby planes ...

Simon

you'd be surprised what low noise generators are on the market nowadays.