Furnace fan motor run directly by natural gas combustion ?

What is the state of the art of natural-gas powered motors?
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
If such a natural-gas combustion motor did exist, then you could have a residential heating solution that would be independant of main utility power and hence could operate during a power blackout.
Related question: What about AC compressor motors run by natural gas combustion?
Wouldn't the use of a natural-gas powered AC compressor motor reduce the electrical load in the summer?
So, what is the current situation regarding small natural-gas powered motors and their use in HVAC systems as a replacement to electric motors?

"HVAC Guy" wrote in message

What is the state of the art of natural-gas powered motors?
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
If such a natural-gas combustion motor did exist, then you could have a residential heating solution that would be independant of main utility power and hence could operate during a power blackout.
Related question: What about AC compressor motors run by natural gas combustion?
Wouldn't the use of a natural-gas powered AC compressor motor reduce the electrical load in the summer?
So, what is the current situation regarding small natural-gas powered motors and their use in HVAC systems as a replacement to electric motors? Yes ,they are called gas turbines....model jet engines are not cheap.

But folks are buying them to fly model planes at 300-400mph or plane or powering helicopters. Even seen some who used a jet engine to heat a boiler system. Can't remember the web site but a company even had a wood powered jet made from turbochargers.

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Arnold Walker wrote:

What is the state of the art of (small) natural-gas powered motors?
Yes ,they are called gas turbines....

I was thinking more along the lines of a piston-operated combustion motor - not a turbine.

"HVAC Guy" wrote in message

So, what is the current situation regarding small natural-gas powered motors and their use in HVAC systems as a replacement to electric motors?

I don't have a direct answer to your question, but there is the Honda micro CHP system which produces hot water and electricity from natural gas. So far, I believe they are marketed mostly in Japan.
http://www.hondanews.com/CatID5065?mid=2005042628647&mime=asc
Vaughn

On Feb 4, 4:31 pm, HVAC Guy wrote:

What is the state of the art of natural-gas powered motors?
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
If such a natural-gas combustion motor did exist, then you could have a residential heating solution that would be independant of main utility power and hence could operate during a power blackout.
Related question: What about AC compressor motors run by natural gas combustion?
Wouldn't the use of a natural-gas powered AC compressor motor reduce the electrical load in the summer?
So, what is the current situation regarding small natural-gas powered motors and their use in HVAC systems as a replacement to electric motors?

There are a lot of internal combustion engines that run on natural gas. Wouldn't a natural gas powered generator be a better option? That way power is provided to the entire home as well as the furnace.

beemerwacker wrote:

I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
There are a lot of internal combustion engines that run on natural gas. Wouldn't a natural gas powered generator be a better option? That way power is provided to the entire home as well as the furnace.

The loss in converting NG to AC and then using AC to power a mechanical process (ie furnace fan) is not very attractive.
Since NG is being piped to a furnace already, and since furnaces already have a waste (combustion) stack, and since the waste heat from a NG-powered fan could be used by the furnace to help in heating the air, I would think it's a no-brainer that a fan run directly by NG combustion would be great for a furnace. Assuming it's quiet.
The problem with a gas powered generator for home use is that it would have to be sized quite large to be able to handle 5 to 10 kw on a continuous basis if you really wanted to cut yourself from the grid. If there is a 10 kw NG generator rated for continuous residential use that will last for 10+ years, then tell me where I can get one.
When are we (in North America) going to see a totally NG-powered residential HVAC solution?
Why are we not seeing it by now?

Vaughn Simon wrote:

I don't have a direct answer to your question, but there is the Honda micro CHP system which produces hot water and electricity from natural gas.

I think it's a shame that there is no direct solution to use NG combustion to drive furnace fans and AC compressors.
Using NG to drive a generator and then use that electricity to run an electric furnace motor and/or electric AC compressor is a waste.

HVAC Guy wrote:

beemerwacker wrote:
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
There are a lot of internal combustion engines that run on natural gas. Wouldn't a natural gas powered generator be a better option? That way power is provided to the entire home as well as the furnace.
The loss in converting NG to AC and then using AC to power a mechanical process (ie furnace fan) is not very attractive.

I imagine that the loss of reliability in switching to an internal combustion engine for the furnace fan would not be very attractive either.

The problem with a gas powered generator for home use is that it would have to be sized quite large to be able to handle 5 to 10 kw on a continuous basis if you really wanted to cut yourself from the grid.

One doesn't have to power the entire home in an emergency.
Anthony

"HVAC Guy" wrote in message

If there is a 10 kw NG generator rated for continuous residential use that will last for 10+ years, then tell me where I can get one.

Why would you want to do that? I have a little 4KW Onan NG genny for standby house power. I figure that fuel would cost me about $700 per month if ran it 24/7. My normal electric bill is about $100. End of story.
If you had a use for all of the waste heat, the story might be different; but probably not when you consider maintenance, depreciation on the equipment, and cost of capital. The grid is the best bargain you will ever get.
Vaughn

Anthony Matonak wrote:

I imagine that the loss of reliability in switching to an internal combustion engine for the furnace fan would not be very attractive either.
One doesn't have to power the entire home in an emergency.

Both items (reliability and minimal electrical generation) could be served by this unit:
http://www.hondanews.com/CatID5065?mid=2005042628647&mime=asc
http://www.appliancedesign.com/CDA/Archives/945ab419cca38010VgnVCM100000f932a8c0____
http://findarticles.com/p/articles/mi_m0FZX/is_8_71/ai_n15341475
"The tightly packaged Honda MCHP system is built around a single-cylinder vertical crankshaft gas engine that Honda developed specifically for this use. The engine, which can operate on natural gas or propane, drives a newly developed 27-pole generator"
"The goal is to operate the engine, with its modest heat output, close to 100% of the time throughout the heating season in order to maximize electricity production."
So there ya go. A single cylinder gas engine designed for continuous use, mainly to drive a 1 kw generator. Heat recovery from the engine is used directly to heat a home or building, and the electricity would presumably be used to run the air-handling fan with some left over for (probably) lighting.
Now if they could build a smaller gas-powered motor to directly turn the fan and maybe a 100 watt generator to power it's own electronic controls, then they'd have something.

On Sun, 04 Feb 2007 18:56:05 -0500, HVAC Guy wrote:

I think it's a shame that there is no direct solution to use NG combustion to drive furnace fans and AC compressors.

There is the possibility using thermoelectric generators but their conversion efficiency is poor. On the small scale there are a couple of stoves that use them for the combustion fans and I think Dellpoint offer one for a pellet stove but it seems not available outside Canada.
AJH

On Sun, 04 Feb 2007 16:31:01 -0500, HVAC Guy wrote:

If such a natural-gas combustion motor did exist, then you could have a residential heating solution that would be independant of main utility power and hence could operate during a power blackout.

The whispergen stand alone product should manage to do this if the parasitic electrical loads were less than 1kW and 10% of the thermal output.
AJH

On Feb 4, 4:31 pm, HVAC Guy wrote:

What is the state of the art of natural-gas powered motors?
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
If such a natural-gas combustion motor did exist, then you could have a residential heating solution that would be independant of main utility power and hence could operate during a power blackout.
Related question: What about AC compressor motors run by natural gas combustion?
Wouldn't the use of a natural-gas powered AC compressor motor reduce the electrical load in the summer?
So, what is the current situation regarding small natural-gas powered motors and their use in HVAC systems as a replacement to electric motors?

It is one of the laws of the universe that, generally, a turbine thermodynamic cycle is only about 36% efficient. The remainder being wasted and disposed of. This means in a power plant (nuclear or coal), the electric output is 1000 megawatts and the waste heat is about 2000 megawatts. All this energy is dumped into the atmosphere (cooling towers) or a river. The drawback to this is the temperature of the waste heat is only about 105 degrees Fahrenheit.
The attendant implication is that for these processes, the higher the temperature differential = a higher efficiency. Waste heat at 105 has what is called low "availability" and a low efficiency. (Thermodynamic term)
There has been attempts to use the waste heat in the colling water in things like a greenhouse. It works well, but is not there when the unit is down for maintenance, usually in the spring or fall. If you have a green house full of plants or crops then you must supplement with other forms of heat.
There has been great strides using the waste heat from a combustion process and increase the efficiency (condensing processes)
Gas turbines on a small scale are about 15% efficient. Condensing the exhaust will increase the efficiency( combined cycle), sometimes greatly. Airplane engine use the large inlet fans as a bypass unit to get more "miles per gallon."
The engineering fact is there are limits to efficiency.
RMcColl

rgmccoll@tds.net wrote:

What is the state of the art of natural-gas powered motors?
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
It is one of the laws of the universe that, generally, a turbine thermodynamic cycle is only about 36% efficient.

First item, I don't think we'll be spinning a furnace fan at 10,000 rpm, so we're not talking about turbines here.
More like a piston.
Second thing, we're probably talking very low displacement. We're only trying to generate 1/4 to 1/2 horsepower.
1 HP = 750 watts, so 1/3 hp = 243 watts
1 BTU per hour = 0.3 watts, 243 watts = 810 btu's per hour
Assuming a 15% efficiency, then we need 5400 btu's per hour. Natural gas has about 1200 btu's per cubic foot. So we need 4.5 cubic feed of NG per hour.
I'm currently paying $2.45 (CDN) per cubic meter (which includes a variety of taxes and charges besides the actual cost for the natural gas). $2.45 CDN = $2.07 US = $1.05 GBP.
1 cubic meter = 34.3 cubic feet = $2.45. 4.5 cubic feet = 0.131 cubic meters = $0.32 per hour.
Since most small electric motors are typically 50% efficient, our original 243 watts needs to double to 500 watts for the actual electrical energy required. That is actually a bit on the low side - this web site:
http://www.dbkpowergenerators.com/Sizing%20Generators.htm
puts the actual wattage needed for 1/3 hp to be more than 700 watts. So I'll assumne 600 watts.
I'm paying 11.2 cents (CDN) per kwatt-hour (all taxes and other charges included). For comparison, 11.2 (CDN) = 4.8 (pence?) = 9.5 cents (US).
600 watts = 0.6 kwatt = 6.72 cents per hour.
So, a small NG-powered motor with a theoretical efficiency of 15% would cost 32 cents per hour to operate, vs 6.7 cents per hour for a comparible electric motor.
But if the waste heat from the motor were input into a heat exchanger, perhaps as a return-air pre-heater for the furnace, then the cost of operation might make this more attractive. Such a motor with waste-heat capture could be used as the sole heat source during the low-demand months of the heating season, with the main furnace burners operating during the middle of the season.

"HVAC Guy" wrote in message

rgmccoll@tds.net wrote:
What is the state of the art of natural-gas powered motors?
I'm talking about something that can replace the typical 1/4 or 1/3 hp electric fan motor in a residential forced-air natural gas furnace.
It is one of the laws of the universe that, generally, a turbine thermodynamic cycle is only about 36% efficient.
First item, I don't think we'll be spinning a furnace fan at 10,000 rpm, so we're not talking about turbines here.
First off if you use a turbine it would replace a Becket gun burner.

Second off when we used turbines for that purpose the boiler did 85% boiler efficiency. The jet is your gun burner.....granted the heating system your have is lower than 3,000,000btu and has more space for a firebox than we had on the boiler.But 100 to 300 pound thrust drone jets fit the ticket as a alternative to a standard gun burner for the system, we were using them on.And as war surplus item was price competitive with a Beckett.

More like a piston.
Second thing, we're probably talking very low displacement. We're only trying to generate 1/4 to 1/2 horsepower.
1 HP = 750 watts, so 1/3 hp = 243 watts
1 BTU per hour = 0.3 watts, 243 watts = 810 btu's per hour
Assuming a 15% efficiency, then we need 5400 btu's per hour. Natural gas has about 1200 btu's per cubic foot. So we need 4.5 cubic feed of NG per hour.
I'm currently paying $2.45 (CDN) per cubic meter (which includes a variety of taxes and charges besides the actual cost for the natural gas). $2.45 CDN = $2.07 US = $1.05 GBP.
1 cubic meter = 34.3 cubic feet = $2.45. 4.5 cubic feet = 0.131 cubic meters = $0.32 per hour.
Since most small electric motors are typically 50% efficient, our original 243 watts needs to double to 500 watts for the actual electrical energy required. That is actually a bit on the low side - this web site:
http://www.dbkpowergenerators.com/Sizing%20Generators.htm
puts the actual wattage needed for 1/3 hp to be more than 700 watts. So I'll assumne 600 watts.
I'm paying 11.2 cents (CDN) per kwatt-hour (all taxes and other charges included). For comparison, 11.2 (CDN) = 4.8 (pence?) = 9.5 cents (US).
600 watts = 0.6 kwatt = 6.72 cents per hour.
So, a small NG-powered motor with a theoretical efficiency of 15% would cost 32 cents per hour to operate, vs 6.7 cents per hour for a comparible electric motor.
But if the waste heat from the motor were input into a heat exchanger, perhaps as a return-air pre-heater for the furnace, then the cost of operation might make this more attractive. Such a motor with waste-heat capture could be used as the sole heat source during the low-demand months of the heating season, with the main furnace burners operating during the middle of the season.

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----