Heat from Mining efficiency

[420]

What is the efficiency for heating using a mining rid let's say 5970 cards, as opposed to an electric heater (1.5kw/H) or even a central heater if you know

[crazyates]

What is the efficiency for heating using a mining rid let's say 5970 cards, as opposed to an electric heater (1.5kw/H) or even a central heater if you know

IIRC, almost all power from a computer is wasted and expelled in the form of heat. I believe if you wanted to match the heat output of a 1.5KWh heater, you would need your mining hardware to pull the same amount of power from the wall. 2x 750W rigs would put out the same amount of heat.

[420]

What is the efficiency for heating using a mining rid let's say 5970 cards, as opposed to an electric heater (1.5kw/H) or even a central heater if you know

IIRC, almost all power from a computer is wasted and expelled in the form of heat. I believe if you wanted to match the heat output of a 1.5KWh heater, you would need your mining hardware to pull the same amount of power from the wall. 2x 750W rigs would put out the same amount of heat.

woo. DO you know how much more efficient central heating is (by gas) to convection heaters? I'm sure I could find info online, thanks

[DeathAndTaxes]

gas (or any combustable heating source) can never be more than 100% efficient.  Law of conservation of energy.  1 BTU of chemical energy in natural gas can at most produce 1 BTU of usable heat.

The very best modern furnaces are 92% to 97% efficient.  Older cheaper furnaces are in the 80%.  If you have a furnace more than 20 years old it is likely is sub 80% efficiency. 

That being said you probably aren't interested in the EFFICIENCY on natural gas heat you are interested in the ECONOMICS.  Natural gas is very cheap in the US (in terms of $/BTU) so even at a lower efficiency the cost per BTU of heat added to the house will generally be less than a electric radiator (to include GPU rig).  How much cheaper?  Depends on a) electric rate, b) nat gas rate, c) furnace efficency but as a ballpark it is roughly 30% to 50% cheaper (per usable BTU).

[420]

gas (or any combustable heating source) can never be more than 100% efficient.  Law of conservation of energy.  1 BTU of chemical energy in natural gas can at most produce 1 BTU of usable heat.

The very best modern furnaces are 92% to 97% efficient.  Older cheaper furnaces are in the 80%.  If you have a furnace more than 20 years old it is likely is sub 80% efficiency. 

That being said you probably aren't interested in the EFFICIENCY on natural gas heat you are interested in the ECONOMICS.  Natural gas is very cheap in the US (in terms of $/BTU) so even at a lower efficiency the cost per BTU of heat added to the house will generally be less than a electric radiator (to include GPU rig).  How much cheaper?  Depends on a) electric rate, b) nat gas rate, c) furnace efficency but as a ballpark it is roughly 30% to 50% cheaper (per usable BTU).

thanks yea totally meant ECONOMICS, by efficiency I guess I was implying financially. now there should be a price per kw and per cubic foot or whatever for natural gas where they are even in terms of cost to heat a house the same way (expel same BTU's)

[DeathAndTaxes]

Yeah your rate may vary but here is my info as an example.
Electrical rate (total charge to the wall) $0.07 per kWh
Natural Gas Rate (total charge to the wall) $0.83 per ccf

1 cubic foot of natural gas has 1020 BTU.
nat gas is usually metered by the 100 cubic feet (ccf) so thats 102,000 BTU
1 kwh is 3412 BTU

So cost for 1 million BTU (arbitrary but I hate working with tiny numbers)
Natural Gas: $8.42 (1,000,000 / 102,000 * $0.83)
Electricity: $20.52 (1,000,000 /3412 * $0.07)

Now electrical resitance heating will always be 100% efficient (it simply can't be anything else).  A good heat pump (as long as you outside air doesn't get below 20F or so) can be 200% to 300% efficient but that doesn't apply to mining.    

At best a furnace* is going to be 97% efficient but most are in the 80% range.  Still at $8.43 / $20.52 =  41% even a malfunctioning furnace operating at 50% efficiency is going to be cheaper.   Nat gas is just crazy cheap in the US.  We keep finding more and more of it.   Hell they might start bringing back natural gas fired heat pumps again.

* Since there seems to be confusion by furnace I mean a device which burns combustible material (i.e. natural gas, propane, fuel oil, wood, garbage, human waste, etc).  Electric heat would be either resistance (100% efficiency) or heat pump (COP of >1 = >100% "efficiency").  At least in the US using the term furnace to refer to electric heat would be uncommon.

[puck2]

The very best modern furnaces are 92% to 97% efficient.  Older cheaper furnaces are in the 80%.  If you have a furnace more than 20 years old it is likely is sub 80% efficiency. 

Electric heat is generally described as 100% efficient due to full conversion of "fuel" to heat.

[superfastkyle]

death and taxes numbers are similar to what I remember from my calculations last year. But if you have poor insulation in a central heating system, they do drastically reduce efficiency. I spent about $220 last February in gas and about $70 in electricity in 2011, 2012 with about $150 worth of mining. I spent $310 this year in electric and about $50 in gas. That was with two extra roommates, to give you some idea. 1300ft house. So I think its safe to assume at least half the mining electricity cost will be free as long as you get the heat circulated

[Fjordbit]

Another option for economics and efficiency is geothermal. Because it's a heat pump, it will put out more heat than it uses in energy (about 5-7x). Natural gas has come down a lot in price, though, and geothermal units are expensive to install, so you'd need to weigh it out.

[420]

Another option for economics and efficiency is geothermal. Because it's a heat pump, it will put out more heat than it uses in energy (about 5-7x). Natural gas has come down a lot in price, though, and geothermal units are expensive to install, so you'd need to weigh it out.

can u provide link, i forget what that means, using earth heat?

[vapourminer]

Another option for economics and efficiency is geothermal. Because it's a heat pump, it will put out more heat than it uses in energy (about 5-7x). Natural gas has come down a lot in price, though, and geothermal units are expensive to install, so you'd need to weigh it out.

I have geothermal, although technically its a ground sourced heat pump. its very efficient - 400% is the ballpark, but Id have to find the papers to be sure. but as superfastkyle pointed out if the ducts (distribution system) are not well done (like uninsulated pipes/ducts running outside the living space) you lose a  lot. I had new ducts run and they are insulated beyond belief.

last year I heated with oil (expensive in the US, getting near to heating with pure electric) and a 25 years old furnace and uninsulated pipes. efficiency wise, my waste heat from mining was pretty close to what my old furnace put out. this years its about 25% efficient compared to my geothermal unit. I heat with dirt now.

[Fjordbit]

Another option for economics and efficiency is geothermal. Because it's a heat pump, it will put out more heat than it uses in energy (about 5-7x). Natural gas has come down a lot in price, though, and geothermal units are expensive to install, so you'd need to weigh it out.

can u provide link, i forget what that means, using earth heat?

Here's a basics:
http://www.youtube.com/watch?v=-ajqiPe_9Ko

They have a loop that pumps ground water up to near the surface. This water is normally about 60-70 degrees F (15-20 C) even during the winter. Then there is a "heat pump" that extracts heat from the water and warms the air. This is the exact opposite action as an air conditioner, and because most heat pumps are reversible, it can be used to provide cold air in the summer (it's more efficient to pump heat into 70 degree water vs 90 degree air). Because the heat really comes from the ground water and not the energy source, it produces more heat than you spend.

420 makes a good point on ducting, but that would apply to a furnace as well.

[kuzetsa]

gas (or any combustable heating source) can never be more than 100% efficient.  Law of conservation of energy.  1 BTU of chemical energy in natural gas can at most produce 1 BTU of usable heat.

The very best modern furnaces are 92% to 97% efficient.  Older cheaper furnaces are in the 80%.  If you have a furnace more than 20 years old it is likely is sub 80% efficiency.  

((...snip...))

Yeah, furances aren't that great. My landlord doesn't have central heating installed for my appartment (heat pump or otherwise) and the only heat we're allowed to use (per terms of the lease) is the electric heater installed in the wall. That has a 100% efficiency for confirting electricity to heat.

100% of electricity used by a computer comes out as heat. ANY electricity coming into a building and being used is ALWAYS converted 100% into heat... with only two main exceptions:

• If you have tons of light indoors and it is pouring out the windows, some of that energy escapes (even though glass is opaque to infra red)
• Amateur radio and you are broadcasting. You are actively sending RF out
• reverse exception being if you have a heat pump. Those things use magic though so they don't count.  

((...snip...))

Now electrical resitance heating will always be 100% efficient (it simply can't be anything else).  A good heat pump (as long as you outside air doesn't get below 20F or so) can be 200% to 300% efficient but that doesn't apply to mining.    

At best a furnace* is going to be 97% efficient but most are in the 80% range.  Still at $8.43 / $20.52 =  41% even a malfunctioning furnace operating at 50% efficiency is going to be cheaper.   Nat gas is just crazy cheap in the US.  We keep finding more and more of it.   Hell they might start bringing back natural gas fired heat pumps again.

* Since there seems to be confusion by furnace I mean a device which burns combustible material (i.e. natural gas, propane, fuel oil, wood, garbage, human waste, etc).  Electric heat would be either resistance (100% efficiency) or heat pump (COP of >1 = >100% "efficiency").  At least in the US using the term furnace to refer to electric heat would be uncommon.

Thanks DeathAndTaxes... but actually, the modern ones are even more efficient than you stated:


  Prepare for your mind to be blown:


Water-to-Air:
Closed Loop: >=17.1 EER; >=3.6 COP
Open Loop: >=21.1 EER; >=4.1 COP
 
Water-to-Water:
Closed Loop: >=16.1 EER; >=3.1 COP
Open Loop: >=20.1 EER; >=3.5 COP

Direct Geoexchange (DGX): >=16 EER; >= 3.6 COP

More heat than you put into it. It's basically an air conditioner running in reverse. Similar tech to the "heat pipe" system used in modern cooling where you can conduct heat better than solid copper or silver by using phase change internally. Or also look at air conditioner efficiency.

See also:

coefficient of performance





So in my case, if my computer is generating ANY bitcoin, it is effectively providing cheaper heat than turning on the crappy heater in the wall.

I just love discussions like this one

[420]

I don't think I made any good points that was someone else's credit, except..

geothermal is the future!

[kuzetsa]

I don't think I made any good points that was someone else's credit, except..

geothermal is the future!

Indeed. My parents use a central-heating type heat pump (apparently, I just looked it up and ALL heatpumps for HVAC systems are generally considered "geothermal" -- learn something every day)

Their energy bill when climate control is needed is much better than mine (in part because they live somewhere with lower energy costs)

Maybe I can convince my landlord to get a geothermal system if the utility company will allow some sort of tax break or an incentive program or something.

For now though, I'm happy to know that as per the original post:

If you are using an electric heater (wall heater, space heater or otherwise) it is just as efficient to leave your computer running (minus wear and tear costs) ... so if I want to mine bitcoin it is fine to do during the winter months.


Edited to add: ... ok I just caught myself repeating. Gonna stop posting on this thread now

[vapourminer]

Another option for economics and efficiency is geothermal.

can u provide link, i forget what that means, using earth heat?

Here's a basics:
http://www.youtube.com/watch?v=-ajqiPe_9Ko

They have a loop that pumps ground water up to near the surface. This water is normally about 60-70 degrees F (15-20 C) even during the winter. Then there is a "heat pump" that extracts heat from the water and warms the air. This is the exact opposite action as an air conditioner, and because most heat pumps are reversible, it can be used to provide cold air in the summer (it's more efficient to pump heat into 70 degree water vs 90 degree air). Because the heat really comes from the ground water and not the energy source, it produces more heat than you spend.

thats not what my geothermal system is. it is a closed loop: 2000 feet of pipe with antifreeze in it, buried 5 feet down in my back yard.

ground temp  5 feet down is around 50F year round in my area (northeast USA), and my system dumps heat into it in the summer, and draws heat from it in the winter.

as a bonus, when cooling my house some of the heat removed is used to preheat my hot water (desuperheater). so last summer my waste heat from the miners actually was used to heat hot water. slick.

[vapourminer]

Maybe I can convince my landlord to get a geothermal system if the utility company will allow some sort of tax break or an incentive program or something.

30 percent federal tax credit for geothermal right now.

[kuzetsa]

Maybe I can convince my landlord to get a geothermal system if the utility company will allow some sort of tax break or an incentive program or something.

30 percent federal tax credit for geothermal right now.

Oh wow thanks. That is promising / wonder how it works out for rental properties.

Do you have a citation from somewhere online so other people (actual home owners) could benefit even if it likely doesn't apply to my case as I'm not a home owner?

[vapourminer]

30 percent federal tax credit for geothermal right now.

Oh wow thanks. That is promising / wonder how it works out for rental properties.

Do you have a citation from somewhere online so other people (actual home owners) could benefit even if it likely doesn't apply to my case as I'm not a home owner?

http://www.energystar.gov/index.cfm?c=tax_credits.tx_index.

What is included in the Tax Credit?

Tax Credit:
    30% of cost with no upper limit
Expires:
    December 31, 2016
Details:
    Existing homes & new construction qualify. Both principal residences and second homes qualify. Rentals do not qualify.

    Geothermal Heat Pumps
    Small Wind Turbines (Residential)
    Solar Energy Systems

Tax Credit:
    Credit Details: 30% of the cost, up to $500 per .5 kW of power capacity
Expires:
    December 31, 2016
Details:
    Existing homes & new construction qualify. Must be your principal residence. Rentals and second homes do not qualify.

[Fjordbit]

Maybe I can convince my landlord to get a geothermal system if the utility company will allow some sort of tax break or an incentive program or something.

30 percent federal tax credit for geothermal right now.

Oh wow thanks. That is promising / wonder how it works out for rental properties.

Do you have a citation from somewhere online so other people (actual home owners) could benefit even if it likely doesn't apply to my case as I'm not a home owner?

Here's a reference:
http://energytaxincentives.org/business/renewables.php#geothermalhp
The tax credit goes to 2016. It doesn't apply to rental properties, but if you are paying for heat, I would say that it could pay for itself in 3-5 years.