That’s the beauty of the Carnot cycle. It moves heat, rather than using an energy source to provide heat directly. So it can move more heat energy than it requires in electric energy. Air conditioners and heat pumps can achieve greater than 100% “efficiency” when you define efficiency as the heat added or removed from the room divided by electricity consumed.
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Shop Heating
- Thread starter jbolt
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That’s the beauty of the Carnot cycle. It moves heat, rather than using an energy source to provide heat directly. So it can move more heat energy than it requires in electric energy. Air conditioners and heat pumps can achieve greater than 100% “efficiency” when you define efficiency as the heat added or removed from the room divided by electricity consumed.
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I updated my profile. I'm not in CA anymore. Now in Southern Oregon so a little colder in the winter and a little hotter in the summer.
I only have 60A to the shop so not sure what a heat pump would require. I'm not sure I really need AC in the shop.
I only have 60A to the shop so not sure what a heat pump would require. I'm not sure I really need AC in the shop.
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Oregon is hotter than CA in the summer? Because of humidity or temp?
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I'm glad someone else on here has the technical info on how this stuff works.
Kevin (K&K Heating) is a trusted friend, I've worked side by side with him and his crew during ice storm emergencies where we had to run generators to keep our customers pipes from freezing. He's not someone who's ever lied to me or anyone I know AFAIK, just doesn't work running a service business in a small town.
Our mini-split in Michigan works fine from -12 to 90 degrees F so far, and it consumes a negligible amount of electricity. It's 21's century technology that doesn't depend on combustion (at least at point of use).
Like I said, consult with someone who does it for a living. Kevin plans on changing his shop over soon, I've watched him grow his business from one van to an entire fleet with a dozen techs, so I think he knows a thing or two....
John
Kevin (K&K Heating) is a trusted friend, I've worked side by side with him and his crew during ice storm emergencies where we had to run generators to keep our customers pipes from freezing. He's not someone who's ever lied to me or anyone I know AFAIK, just doesn't work running a service business in a small town.
Our mini-split in Michigan works fine from -12 to 90 degrees F so far, and it consumes a negligible amount of electricity. It's 21's century technology that doesn't depend on combustion (at least at point of use).
Like I said, consult with someone who does it for a living. Kevin plans on changing his shop over soon, I've watched him grow his business from one van to an entire fleet with a dozen techs, so I think he knows a thing or two....
John
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It is a cheating number. Efficiency (or any %) is really a ratio of two things. But you can play games with what you are counting. Electric resistive heat is pretty close to 100% if you count watts of electricity at your power meter vs watts of heat produced. Only inefficiency is the very slight heat lost in the wires from your meter to the actual heater.
But, if you use a heat pump, you can essentially create more heat in a room than watts of electricity used. The extra "energy" comes from cooling the great outdoors. So the argument really is a heat pump produces 3x as much heat as a resistive heater for the same amount of electricity used. "Therefore it is 3x as efficient." Since most people care about heat produce per $ of electric bill, it is true on a watts per dollar basis.
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Not gonna get into a debate here, yes I know about the second law of thermodynamics. This man taught me about it.
www.hobby-machinist.com
Pretty sure when you talk about efficiency it's in comparison to something else, (ie. radiant gas heat), so relevant for this conversation.
John
A very special day
US manned space flight resumes today. Watching it from a laptop on top of my dad's old workbench. https://www.spacex.com/launches/ John
www.hobby-machinist.com
Pretty sure when you talk about efficiency it's in comparison to something else, (ie. radiant gas heat), so relevant for this conversation.
John
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The Pioneer mini-split uses 6.8amps at 240V for their 18,000 BTU unit. I believe that's running amperage not startup, but they are inverter (VFD) based so I would imagine the startup surge is not horrid.
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wow, your dad skipped 2 grades. very impressive. Not many men fly across the country in a small plane. Yes many do, but many don't.Not gonna get into a debate here, yes I know about the second law of thermodynamics. This man taught me about it.
A very special day
US manned space flight resumes today. Watching it from a laptop on top of my dad's old workbench. https://www.spacex.com/launches/ John
Pretty sure when you talk about efficiency it's in comparison to something else, (ie. radiant gas heat), so relevant for this conversation.
John
that's a tough task navigating and flying at the same time across the country. Is he still around?
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I'll be installing a Mr Cool mini split with my son possibly this weekend if it gets here Friday like it's supposed to.
I guess I am having a hard time understanding how something is more efficient than 100%.. I guess I'm thick..
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The real question is 'Why do I care how efficient it is?'. For the same technology, more efficient should mean less cost, but comparing electric heat pumps to combustion heat is apples to oranges, given that it is unlikely your energy sources cost the same.