Air Conditioners.

[haha]

when you buy an airconditioner here in bangkok, the new unit comes with a plastic fan component. but when people need to replace the fan component, they do so with a metal component.

since everybody is trying to save money, why do they use a metal fan component?

I always thought a plastic fan component would use less electricity. right?

across from my apartment building is another large apartment building. and get this, all the fan components are made of metal.

can you imagine all the electricity that would be saved if every airconditioner in bangkok had plastic fan components?

..just a thought.

[thai_norman]

The fan in the compressor unit???I thought they was always metal, hold on, let me climb out onto the ledge where it is and take my compressor apart, be back in about 5 minutes.

Normans Wife.

I am afraid Norman for some reason decided to jump out of our 16th storey condo..

[haha]

The fan in the compressor unit???I thought they was always metal, hold on, let me climb out onto the ledge where it is and take my compressor apart, be back in about 5 minutes.

Normans Wife.

I am afraid Norman for some reason decided to jump out of our 16th storey condo..

<{POST_SNAPBACK}>

well, I guess that's one way to save on the cost of a divorce. ladies... pay notice.

[Khun Jean]

since everybody is trying to save money, why do they use a metal fan component?

I always thought a plastic fan component would use less electricity. right?

In the process of buying a new air conditioning, what would be the reason a plastic fan using less energy?

I thought if the fan was more heavy it would act more like a 'fly-wheel' (sp). And the speed would be more even. Using the same or even less energy. The ball-bearing part would be the most important i think. I want that to be of metal as it has a longer live span.

[haha]

since everybody is trying to save money, why do they use a metal fan component?

I always thought a plastic fan component would use less electricity. right?

In the process of buying a new air conditioning, what would be the reason a plastic fan using less energy?

I thought if the fan was more heavy it would act more like a 'fly-wheel' (sp). And the speed would be more even. Using the same or even less energy. The ball-bearing part would be the most important i think. I want that to be of metal as it has a longer live span.

<{POST_SNAPBACK}>

I'm not an expert on the subject. but I think it has to do with weight. the more weight you have to move, the more energy you exert.

maybe someone here in thailand can do a study comparing the use of metal vs. plastic fans to confirm the energy savings. it shouldn't cost much money. but if it saved even 5%, that would be a substantial savings in electricity if you look at the whole country doing it.

same with toilets.. in america, they talk of saving water by alternating the use of toilets. putting a brick in the toilet will save water per flush. sounds silly, but evidently, if you are having a drought, you need to think of ways to save water. everybody can contribute to the cause.

just brainstorming for the common cause.

[expatinasia]

haha,

Do you think there's a wide spread conspiracy to cause people getting replacement air conditioner fan blades to use more electricity? Rather than ask us, why didn't you ask the guy who replaced the fan blade? The plastic fan blades break, causing a loss of AC efficiency, and additional wear on the fan motor. Metal fan blades bend, but last a lifetime. As for electricity savings of 5% using a plastic fan blade, that's funny beyond belief

[cdnvic]

I'm not an expert on the subject.  but I think it has to do with weight.  the more weight you have to move, the more energy you exert.

maybe someone here in thailand can do a study comparing the use of metal vs. plastic fans to confirm the energy savings.  it shouldn't cost much money.  but if it saved even 5%, that would be a substantial savings in electricity if you look at the whole country doing it.

same with toilets..  in america, they talk of saving water by alternating the use of toilets.  putting a brick in the toilet will save water per flush.  sounds silly, but evidently, if you are having a drought, you need to think of ways to save water.  everybody can contribute to the cause.

just brainstorming for the common cause.

The heavier fan will use more energy to start up, but probably less to keep going as polished metal and momentum from the weight of the fan would help overcome drag on the fan blades.

As for saving water, better to have one good flush than 3 smaller ones which is what most low volume toilets make people do.

I sawa system in NZ once where waste water from the showers and sinks was used to flush the toilets, that makes alot more sense. Just so long as you don't hook it up backwards.

cv

[bino]

The heavier fan will use more energy to start up, but probably less to keep going as polished metal and momentum from the weight of the fan would help overcome drag on the fan blades.

I'm no expert / physicist either, but it seems to me that overcoming the drag on a fan blade would be defeating its purpose. The blades should be under a constant amount of drag as they are consistently "biting into" and moving air?

[andy50]

hi all, regarding the start-up load of the motor,

here in the uk i connect lots of a/c units ,the fans are electronically-speed controlled and as such they start very "softly"and gradually get up to speed the blade speed constantly varies during operation, depending on conditions in the building,so theres no extra start up load as such (imho)that is!

[Jeff Jarvis]

A heavier fan is cheaper to spin than a lightweight fan?

[bino]

This question has been stuck in my head, so I did some google research on boat propellors, which are essentially the same thing. There is a lot of information available about "buying the right propellor".

It seems there may be some merit to haha's theory. Many sites offer the opinion that a light weight carbon fiber composite propellor will save fuel, and spin up to maximum RPM faster. The downside is that the blades are subject to flex which will decrease efficiency. Even aluminum props are subject to flex. Stainless steel and bronze are the stiffest.

But if you think about it (or sleep on it like I did) you will realize that the compressor is the biggest electicity drain in an aircon system, not the fan. Many people who don't use aircon will run a 16 inch pedestal fan instead, and see only a negligible amount of electricity used on the monthly bill.

But- even negligible amounts can add up. If somebody offered me one baht for every aircon fan in Thailand, I'd sure as h*ll take it!

[doctormann]

<{POST_SNAPBACK}>

The heavier fan will use more energy to start up, but probably less to keep going as polished metal and momentum from the weight of the fan would help overcome drag on the fan blades.

<{POST_SNAPBACK}>

I'm no expert / physicist either, but it seems to me that overcoming the drag on a fan blade would be defeating its purpose. The blades should be under a constant amount of drag as they are consistently "biting into" and moving air?

<{POST_SNAPBACK}>

Absolutely right! No drag, no air flow, no point!

The weight of the fan is not really relevant - takes a miniscule amount more energy to spin a heavy fan up to speed but you get this energy back (mostly) when you remove the driving force because there is more energy stored by the system - i.e the fan keeps going longer when you take the power off but the effect is really very small. As has been pointed out elsewhere, the main reason for using a metal fan is that they last for ever and plastic ones don't.

[thai_norman]

wouldnt a plastic fan have to be thicker than a metal fan there by making it less aero dynamic?

[astral]

If you have to replace the fan then do so with the one recommended

by the manufacturer.

He spent a lot of money on research, why do you think you know better?

[bino]

If you have to replace the fan then do so with the one recommended

by the manufacturer.

He spent a lot of money on research, why do you think you know better?

Disagree with you totally... most manufacturers find the adequte solution with the lowest production cost.

For example, tires on cars. Why don't auto manufacturers equip new cars with top of the line, better performing, longer lasting tires?

[thai_norman]

If you have to replace the fan then do so with the one recommended

by the manufacturer.

He spent a lot of money on research, why do you think you know better?

<{POST_SNAPBACK}>

Disagree with you totally... most manufacturers find the adequte solution with the lowest production cost.

For example, tires on cars. Why don't auto manufacturers equip new cars with top of the line, better performing, longer lasting tires?

<{POST_SNAPBACK}>

They do, on top of the line cars

[frequentatore]

If you have to replace the fan then do so with the one recommended

by the manufacturer.

He spent a lot of money on research, why do you think you know better?

<{POST_SNAPBACK}>

Disagree with you totally... most manufacturers find the adequte solution with the lowest production cost.

For example, tires on cars. Why don't auto manufacturers equip new cars with top of the line, better performing, longer lasting tires?

<{POST_SNAPBACK}>

Production costs don't always come first. Put a plastic fan outside and see how long it lasts... I would say one year. The plastic will dry and the blades will break!