Gas powered A/C ( whats` it all about )

[TRASH101]

good day to you chaps

I ask of you this day for clarification on A/C powered by natural gas. Stuff like comparative performance, economic viability, enviromental impact, reliability and does anybody like it.

your comments will be most welcome.

[chabby]

hello ...there are mainly two types of natural gas systems we have down here...one is the type of Chillers that are being driven by an engine powered by Natural gas and the other type that are of absorbtion design that uses Natural gas .. initial cost very expensive and also maintenence but it pays off in the long run

[Brian_UK]

Used to like the Robur units, gas fired, 13amp plug fed for controls and built in pump.

They have improved since then but still worthwhile I think.

Google finds quite a few around.

[TRASH101]

Thanks for your responses

I was enquiring more to the gas powered VRF by such as Sanyo. (is there other manufacturers ?)

Bits that worry me are as follows ; comp. shaft sealing, motor heat/ exhaust (I take it that this is a combustion engine), increase in physical size of condenser unit and involvement of third parties for the gas side.

not much experience with absorbtion chillers but I can remember helping a colleague with an oil flush. I was not happy

[Pol]

It`s a combustion engine indeed - the outdoor unit`s half a car, half a vrf really. Compressors in most systems are blt - driven, so shaft sealing is not really an issue I suppose.

No defrost cycle apparently, as the heat of the engine keeps performance up and coil ice - free.

As to size of outdoor unit, here`s some commercial doc on the Sanyo unit; http://download.yousendit.com/2AB273E822B4E0A7

There`s also Aisin, ( sold as Daikin GHP and Samsung GHP in Asia, Aisin in Europe with different brand indoor units).

[TRASH101]

Thank you very much pol

It all makes more sense now although the motor efficiency cant be as good as an inverter controlled electric of similar output can it ?

Plus the g/Kg CO2 must surely condem its long term future.

[frank]

not much experience with absorbtion chillers but I can remember helping a colleague with an oil flush. I was not happy

An oil flush on an absorption machine Trash? I think you mean an ammonia system

http://en.wikipedia.org/wiki/Gas-abs...n_refrigerator

[Pol]

The engine efficience isn`t too bad, as it is a variable speed type engine, as in a car. The Aisin I believe works on four speeds, and couples more ore less compressors on the engine depending on load to control capacity.

As to CO2 emission, the electricity for a EHP has to be produced by burning coal or gas ( or in a nuclear plant of course). If you bring both systems back to usage of primary energy, CO2 emissions of a GHP appear competitive with EHP.

Pol

[TRASH101]

Memory is a little hazy as its been 9 years since I have worked on ammonia, but I`m fairly sure it was an ammonia continous absorption system with an hydraulic diaphragm pump (belt driven from electric motor). As I recall the diaphragm split and contaminated the motor oil. In fact this was a common occurence on all of these units. I do remember a company from Hemel Hempstead coming in who "specialised" in these units and got no further than we did. I was quite naieve at the time and took the problem all too seriously and nearly threw the job in.

Can`t even remember the manufacturer but since then I have always wondered if the solution was bypassing the one way valve from the pump to the generator.

[Brian_UK]

Hey Trash, does the name Birdsall ring a bell. I used to work in the next town along and had dealings with them - they're still going strong by the looks of it.

[Contactor]

Does anyone know the COP for these machines?

[TRASH101]

Good guess Brian

I reckon they must be doing OK. Saw them last year, or at least their service team, at a Hospital the other side of the M1. They had for forgotten to put the condensate drain on a humidifier lance if I remember correctly.

[Pol]

Contactor, from my info COP`a usually are somewhere between 1,10 to 1,20. Manufacturers say this is pretty similar to EHP performance; in primary energy use this should be equal to an EHP performance of 3,4 to 3,8.

Pol

[Jacek]

Thanks for your responses

I was enquiring more to the gas powered VRF by such as Sanyo. (is there other manufacturers ?)

Bits that worry me are as follows ; comp. shaft sealing, motor heat/ exhaust (I take it that this is a combustion engine), increase in physical size of condenser unit and involvement of third parties for the gas side.

not much experience with absorbtion chillers but I can remember helping a colleague with an oil flush. I was not happy

Hi guys,

I meet two brands in Poland in the field of GHP VRF: Sanyo and AISIN Toyota (through Italian distributor Technocasa). AISIN Toyota used Hitachi and Mitsubishi indoor units and control. Starting from this year, AISIN Toyota use Daikin's indoor units and control. I've heard recently Daikin will offer Toyota's GHP from next year.

Keep in touch

Jacek

[Jacek]

hello ...there are mainly two types of natural gas systems we have down here...one is the type of Chillers that are being driven by an engine powered by Natural gas and the other type that are of absorbtion design that uses Natural gas .. initial cost very expensive and also maintenence but it pays off in the long run

Hello,

There are many manufacturers of gas-driven absorption chillers (heaters). Absorption chillers are hundreds (thousands) of kW in most cases. But Broad and Yazaki, especially Broad have small absorption chiller (from a dozen or so kW up to 150 kW). They become very popular in Poland and are the alternatives for GHP VRF systems (provided by Sanyo and some Toyota).

Best regards,

Jacek