Solar-Assisted Air-Conditioning In Thailand

[simon43]

I have been reading about solar-assisted air-conditioning, where a thermal collector is used to reduce the amount of energy needed to run the compressor of the air-con unit. This is a hybrid type of air-con, connected to the mains electricity supply in the normal manner.

On my current building project, I am nearing the point of purchasing 5-10 air-con units. This project has a 'weak' 3-phase supply, and it's imperative that I minimise the overall energy demand (current consumption) of the project.

To this end, I am using solar water heaters for my bathrooms' hot water, and a range of solar-powered garden lighting.

The air-con units represent the greatest energy demand for the project, and my investigations indicate that inverter air-con units do not have the characteristic 'hard-start' current demand surge of non-inverter air-con units.

But what about solar-assisted inverter air-con units? It seems that this type of technology is commonplace in Australia, yet I have not found a supplier here in Thailand.

Does anyone on the forum have experience of this hybrid type of air-con unit?

On a more general note, I am keen to incorporate 'green' concepts into this project, such as grey water and rain water re-use systems, recycling plastic, composting kitchen vegetable waste etc. This is not just a 'tree-hugging' ambition. There are good commercial reasons for a hotel to incorporate these ideas into their business - not least is the opportunity to be given public recognition of their efforts in this area.

So I'm also keen to hear about other ideas for waste recycling, energy reduction/re-use etc.

Simon

[JohnC]

An admirable project, you say these air con units are freely available in Australia so why not start there with the manufacturer and enquire if they have any agents/customers in Thailand?

[Naam]

Simon,

from your postings i have realised since several years that you are an honest and nice chap. however, your lack of indepth technical knowledge makes you a partial dreamer.

solar-assisted airconditioning is indeed possible. there are two ways but both (i assume) do not fit into your financial planning as they are two expensive as far as parts and as well as installation is concerned. one is photovoltaic assistance, i.e. solar panels which produce electricity, the other one is the age-old absorption system which one could find 40 years ago in hotel minibar fridges where heating of the media was done by using simple electric energy.

as the photovoltaic "dead horse" system has already been flogged in various Thaivisa topics i limit my comment to absorption and call it too a "dead horse" which i am not willing to flog. simple reason is that the size of your planned project and of course your budget does not justify to go into details.

i hope we are still friends?

[simon43]

Dr Naam, I value your advice in this matter, since it would appear that you are something of an expert

As an engineer (in another life), I'm aware that PV is unrealistic for my project needs.

However, (if mods allow this url), please take a look at:

http://www.aircondirect.com.au/solar-air-conditioning/

This hybrid air-con system seems to use solar thermal energy to assist in the cooling process of the air-con system. And for sure, solar thermal is a viable non-voltaic energy source.

Or is this product just a lot of hot air??

Simon

[Crossy]

These chaps (also in Oz) also do solar assist A/C http://www.solakool.com.au/ wonder what the price is compared to conventional.

[Darrel]

I wonder how you get it fixed when it goes wrong? Especially here.

Sounds a bit like proprietary car engine management systems that can only be repaired by the main dealer, inevitably at huge extra cost.

[thaicbr]

surely you would be better off fixing the 'weak' 3 phase.

[seekingfriends]

hi guys. solar powered air/con still the thing of dreams. i am in sydney as i type and i have never heard of such a system .the big thing in aust at the moment is producing solar energy from solar panels. and the energy comp will buy it back from you . about 60000 homes in sydney are doing it ,but and this is the but there used to be a goverment rebate towars the price of the system ,the rate they are buying it for is a lot more than it costs them to produce in there own power stations. so they have droped the rate they pay to new customers who sign up to the deal .as a result the number of people getting solar power systems has droped and there is no longer a goverment rebate towards the cost of the system .and the only comp producing solar panels .has stoped producing the panels in aust. and they import the panels from china as the demand has droped that much . james in sydney . ps its a lovely sunney day 23 deg .with a slight breeze

[simon43]

surely you would be better off fixing the 'weak' 3 phase

That is an option, but the quote from the local electricity office is about 1 million baht to provide the transformer and poles to bring the upgraded 3-phase power lines to my location - about 400 metres from the existing high grade 3-phase supply.

This is a 'Thai' price for the work, not an inflated 'farang' price. The bottom line is that the infrastructure investment in this area is very much lacking and some authorities will only do the necessary work if it is (personally) worth their while. Money has to pass hands even to get the relevant officers to come out of their office to inspect/advise on what solution is possible,

I (and others with businesses in this area) have to work with what we can get.

Besides, is it not better for the environment to implement a solution which helps to minimise energy demand and so obtain a greener solution all-round?

@seekingfriends - I am not talking about solar-powered air-con. The product is a hybrid-powered air-con that uses solar thermal, not PV to assist in the operation of the air-con unit.

Edited October 15, 2011 by simon43

[thaicbr]

"I (and others with businesses in this area) have to work with what we can get."

Well i would have thought if all involved share the cost that is the best way.. as for the environment your running a business not green peace.. it's good to think about that but the real world is profits.

but good on you to be thinking this way.

you have probably found this already but..

http://www.lennox.com/solar-solutions/

http://www.alibaba.com/product-free/106531821/Solar_Assisted_Air_Conditioner_Mini_Split.html

Edited October 15, 2011 by thaicbr

[simon43]

Well i would have thought if all involved share the cost that is the best way

That is not how it works

- The electricity infrastructure is lacking in this area

- The cost of bringing the upgraded supply is paid by the first business who 'bites the bullet' and pays

- The other businesses can then obtain the upgraded supply without having in invest in the upgraded infrastructure

'Sharing the initial cost' is a concept that is not apparently understood in my region

as for the environment your running a business not green peace.. it's good to think about that but the real world is profits.

I agree, and higher profits and greater business success can be obtained by:

- Reducing energy expenditure in the business

- Including 'green' solutions in the business which can increase guest bookings, (many customers would prefer to stay at a 'green' hotel rather than one which is operating with scant regard for energy wastage and the local environment - there are international travel awards given to hotels which make an effort to save energy and to recycle etc)

Simon

[Naam]

Dr Naam, I value your advice in this matter, since it would appear that you are something of an expert

As an engineer (in another life), I'm aware that PV is unrealistic for my project needs.

However, (if mods allow this url), please take a look at:

http://www.aircondirect.com.au/solar-air-conditioning/

This hybrid air-con system seems to use solar thermal energy to assist in the cooling process of the air-con system. And for sure, solar thermal is a viable non-voltaic energy source.

Or is this product just a lot of hot air??

Simon

it's not fully hot air Simon. i mentioned that the principle exists since decades and is used for small fridges except that the heating up is done by either electricity or gas. hot air in my [not so] humble opinion is the claim "electrically powered compression is only needed for 2 minutes out of 10" and completely rubbish misleading is "compared to a conventional system where it runs on average 8 minutes out of 10."

there is no way that a thermal collector, especially not the size shown, can replace by absorption 80% of the capacity of a conventionally driven compressor. period!

interesting in marketing is always that "technical" expressions are used without the slightest hint how certain features are achieved or what exactly they mean. in the link you provided it says "The Thermal Collector super heats..."

moreover, i see another hurdle. what if there is not enough sun radiation but your guests demand airconditioning? will you tell them to patiently wait for sunshine because your electrical supply is insufficient?

there might be another and much cheaper way to solve your problem. unfortunately i'm not expert enough to provide more than a rough idea. i mean a control unit which does not allow synchronous start (or even runs) of x numbers a/c compressors but "allocates" power and runtime individually. we used a similar system many rainy seasons ago in the big office building (>60 aircon units) of a factory in the african bush, it worked and nobody complained about lacking cooling capacity.

real experts like Crossy might be able to go into details and if i'm not mistaken TV-member "Genset" would be able to design and build that gadget.

[Naam]

These chaps (also in Oz) also do solar assist A/C http://www.solakool.com.au/ wonder what the price is compared to conventional.

these people seemed to be honest instead of making wild claims:

The size of the compressor is reduced

The condenser efficiency is greatly improved by preheating the refrigerant

The electrical requirement is significantly reduced

These three differences can save the cost of air conditioning your home by using less energy to operate the compressor, the compressor is not required to operate as often and reducing the size and supply of the electrical wiring can save installation costs.

[Spoonman]

- Including 'green' solutions in the business which can increase guest bookings, (many customers would prefer to stay at a 'green' hotel rather than one which is operating with scant regard for energy wastage and the local environment - there are international travel awards given to hotels which make an effort to save energy and to recycle etc)

Simon

Given that what you are building what amounts to nothing more than a Transit "hotel" I reckon people who would be attracted to your "hotel" don't give a flying fig as to the carbon foot print of the place rather is the shower hot and the bed comfortable.

[simon43]

Given that what you are building what amounts to nothing more than a Transit "hotel" I reckon people who would be attracted to your "hotel" don't give a flying fig as to the carbon foot print of the place rather is the shower hot and the bed comfortable.

Ah OK. So because the guests don't give a flying fig to the carbon foot print, is that justification for me (as hotel owner), not giving a flying fig about doing my little bit to help the environment?

You know what my strong belief is? It's human nature to be greedy, lazy and selfish, because it's very easy to achieve that goal. Don't believe me? Look around you...

I'm not a tree-hugger, but if I can incorporate products and processes into my little projects that are within my budget, help the environment and do not degrade the quality of service that my guests expect - then there really is no reason not to do it, is there??

Oh sorry - I forgot the 'I cannot be bothered/too much effort/it's not my problem' arguement

Just saying

Simon

[Crossy]

there might be another and much cheaper way to solve your problem. unfortunately i'm not expert enough to provide more than a rough idea. i mean a control unit which does not allow synchronous start (or even runs) of x numbers a/c compressors but "allocates" power and runtime individually. we used a similar system many rainy seasons ago in the big office building (>60 aircon units) of a factory in the african bush, it worked and nobody complained about lacking cooling capacity.

real experts like Crossy might be able to go into details and if i'm not mistaken TV-member "Genset" would be able to design and build that gadget.

It's called Maximum Demand Control, basically allows intermittent loads (like aircon) to share the available power by switching them sequentially. Try a Google, the systems I saw with a quick look are really intended for large operations who are penalised by the supply authority for exceeding their maximum demand quota, no reason at all why it shouldn't work for Simon.

[aussiebebe]

The Solar-Assisted air conditioners from Solakool and Aircondirect look interesting, I wonder whether they work, I've never tried or even seen them before. I read Dr Naam's post about olf fridges but is this not new technology for air-cons, only released this year? It looks a world away from the PV air con LG released last year: I read the website linked to above "The Thermal Collector super heats and pressurises the gases working in place of the compressor at every opportunity, so electrically powered compression is only needed for 2 minutes out of 1

[simon43]

I've actually found a British-Thai company in Bangkok that manufactures solar-assisted (thermal) air-con units. So I'm getting some more details and will maybe go up to visit their factory etc.

Simon

[Crossy]

That's excellent news Simon.

Keep us informed, if efficiency is as claimed and price is sensible could be using same myself.

[Naam]

It's called Maximum Demand Control, basically allows intermittent loads (like aircon) to share the available power by switching them sequentially. Try a Google, the systems I saw with a quick look are really intended for large operations who are penalised by the supply authority for exceeding their maximum demand quota, no reason at all why it shouldn't work for Simon.

as i mentioned it worked 30 years ago in the african bush with a crudely rigged controller system and it should work for Simon too. advantage is big bang for not too many bucks and no, or hardly any, maintenance cost.

[Naam]

I've actually found a British-Thai company in Bangkok that manufactures solar-assisted (thermal) air-con units. So I'm getting some more details and will maybe go up to visit their factory etc.

i think you are wasting your time Simon. novelties are always marketed with a huge mark-up except in cases when you enter into an agreement to use your setup as a marketing tool.

[Litlos]

I was trying to look at thermal storage systems as they can offer some benefits of load levelling. However slow internet connection at work so cannot check. However generally with these types of hybrid systems there needs to be allowances made during the design and I think they are more aimed at larger commercial applications.

A few ideas that may help. Install fans in the rooms as a lot of people just like air movement and not worried about cooling so much, I only switch on AC for a few minutes before going to bed to knock down the hmidity and temperature a bit, then fan for the night. Insulation of all types will reduce cooling needs, this includes ceiling and decent curtains on windows etc. There is plenty of good information on this either here or the other cool thai house forum. Inverter style AC do generally have a lower power draw during compressor starting. Get restart timers installed on the heavy loads and set them to various timings up to about 5 minutes, thus when a blackout occurs all the heavy loads are not coming on at the same time and overloading the supply. A restart timer is simply a timer installed in the control circuit to delay the start by x seconds.

Best of luck

[EvilDrSomkid]

I've actually found a British-Thai company in Bangkok that manufactures solar-assisted (thermal) air-con units. So I'm getting some more details and will maybe go up to visit their factory etc.

Simon

These guys? http://www.saveenergyasia.com/products/solaraircon.html

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.

btw, we installed 2 Samsung Smart inverter AC units in our office. Works pretty good, quiet, too. Once the air tempo inside is good, the system is near idling to keep it there.

[InterestedObserver]

It's called Maximum Demand Control, basically allows intermittent loads (like aircon) to share the available power by switching them sequentially. Try a Google, the systems I saw with a quick look are really intended for large operations who are penalised by the supply authority for exceeding their maximum demand quota, no reason at all why it shouldn't work for Simon.

as i mentioned it worked 30 years ago in the african bush with a crudely rigged controller system and it should work for Simon too. advantage is big bang for not too many bucks and no, or hardly any, maintenance cost.

Will Simon actually be changed for kWh based on demand or is he just trying to find a super efficient aircon system.

[Crossy]

It's called Maximum Demand Control, basically allows intermittent loads (like aircon) to share the available power by switching them sequentially. Try a Google, the systems I saw with a quick look are really intended for large operations who are penalised by the supply authority for exceeding their maximum demand quota, no reason at all why it shouldn't work for Simon.

as i mentioned it worked 30 years ago in the african bush with a crudely rigged controller system and it should work for Simon too. advantage is big bang for not too many bucks and no, or hardly any, maintenance cost.

Will Simon actually be changed for kWh based on demand or is he just trying to find a super efficient aircon system.

Nah, his problem is that he has a weak 3-phase supply with no financially viable upgrade path, trying to get a quart from a pint pot.

[Naam]

A few ideas that may help. Install fans in the rooms as a lot of people just like air movement and not worried about cooling so much, I only switch on AC for a few minutes before going to bed to knock down the hmidity and temperature a bit, then fan for the night.

so Simon should tell his paying hotel guests to switch on the a/c for a few minutes before going to bed? and what "lot of people" will book and stay in a room in Simon's hotel who just like air movement?

[Naam]

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.

[SantiSuk]

surely you would be better off fixing the 'weak' 3 phase

That is an option, but the quote from the local electricity office is about 1 million baht to provide the transformer and poles to bring the upgraded 3-phase power lines to my location - about 400 metres from the existing high grade 3-phase supply.

This is a 'Thai' price for the work, not an inflated 'farang' price. The bottom line is that the infrastructure investment in this area is very much lacking and some authorities will only do the necessary work if it is (personally) worth their while. Money has to pass hands even to get the relevant officers to come out of their office to inspect/advise on what solution is possible,

I (and others with businesses in this area) have to work with what we can get.

Besides, is it not better for the environment to implement a solution which helps to minimise energy demand and so obtain a greener solution all-round?

@seekingfriends - I am not talking about solar-powered air-con. The product is a hybrid-powered air-con that uses solar thermal, not PV to assist in the operation of the air-con unit.

My sympathies. I was quoted 300,000 baht just to bring the 3 phase down from a pole immediately outside our front gate - then 200,000 then 100,000: the latter two quotes were described as being 'with corruption' by my wife, so I didn't bother and we struggle along using only 2 aircon units at a time (not a hassle surprisingly as 1 unit seems to cool the whole house except in the height of the hot season and Thai kids seem happy to sleep with fans only). These 3rd world countries with their petty grasping officials suck sometimes.

[simon43]

so Simon should tell his paying hotel guests to switch on the a/c for a few minutes before going to bed? and what "lot of people" will book and stay in a room in Simon's hotel who just like air movement?

Well, the situation is not that bad Perhaps I can stagger the arrival of my guests?

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

The middle-managers at the electricity company have stressed that they do not want any problems with the supply to me, (due to overloading etc), since any issues will probably come to the notice of their boss...

So, it is sensible for me to select low-current demand or solar-powered products for the project, to minimise the overall current demand.

In particular, I want to minimise/eliminate the hard-start current surge that conventional air-con units have.

As to using fans in the rooms, it might surprise you that (from previous experience), many western customers do not like to use air-con units and prefer a cooling fan or two. Indian customers generally switch on the air-cons at the lowest temperature setting, and then demand extra blankets

Perhaps I should ban Indian guests, based on their excessive use of the air-con?????

Simon

Edited October 16, 2011 by simon43

[garrfeild]

- Including 'green' solutions in the business which can increase guest bookings, (many customers would prefer to stay at a 'green' hotel rather than one which is operating with scant regard for energy wastage and the local environment - there are international travel awards given to hotels which make an effort to save energy and to recycle etc)

Simon

Given that what you are building what amounts to nothing more than a Transit "hotel" I reckon people who would be attracted to your "hotel" don't give a flying fig as to the carbon foot print of the place rather is the shower hot and the bed comfortable.

I would have to agree with spoonman. With respects to you Simon and your idealism to create green accommodation. You are looking at a whole lot of expense Just to open your doors. Especially if you are thinking anything solar (why not try wind power) even having to think about bringing 3 phase electricity to the plot. Sorry but its obvious your location is not in the best of places as far as utilities are concerned or passing trade! You really have to be sure you will get customers, regardless of how green you go. Are you aiming for international recognition? with your green credentials?

Basically spend as little as you can and if it's so important to you, you can upgrade as and when. But to piss away a load of dosh on something you don't know for sure will work out for you is foolhardy to say the least. But I wish you luck none the less.