Heat Pump in Cold Climate?

[krw]

At some low temperature, yes.

Good Lord! Read!

Nope, but it wouldn't be the first time you've been completely wrong. Illiteracy will do that.

I've noticed that whenever you say the above, you're lying.

Yep. You're lying again.

No, some of it is "generated" outside.

If some is outside (it is), at some (low) temperature, certainly. As the efficiency of the system goes down, at some point the gain from pumping is offset by the energy dissipated (uselessly) outside. At that point the heat pump costs exactly the same as resistive heat, to operate.

Idiot. As the temperature goes down, the efficiency goes down (at some point it stops working altogether) and the energy hill gets higher. Somewhere along the line the unit can no longer push heat up the hill. If there is heat lost outside (there is), the unit is no longer putting out more heat than the electricity it's consuming (total inside and out - both cost the same $$).

Are you really that stupid? If a heat pump moves twice as much heat as it uses, it costs 1/2 to 1/3 as much as resistive heat (resistive heat costs 2-3x more).

There's that lie tell, again.

Yep. At some point, resistive heat will be on par with a heat pump. Gotta be.

You really are that stupid. Amazing.

I made no mistake. You're simply too stupid to read. ...or think.

[Art Todesco]

Ok, here's some explanation on my earlier post. The BTUs/KWHr (3.413) came from the internet, which seems about right. The average 1500 watt electric heater is usually in listed (if you can find it) at about 5K BTUs. The numbers for the heat pump came from the manufacturer's sheet posted earlier in this thread, for 17 degrees outdoor air temp. Sorry I missed the part about "at 17 degrees." Now, if the outside air is 45 degrees, you'd see much bigger BTU numbers. And, of course, that's why we use heat pumps. But at 17 degrees, the inside are will probably feel cold, even though there is some heat being added.

[trader4]

OK, that part I agree with. A 1500 watt electric heater would give you 5100 BTU.

=A0>The numbers for the heat pump came from the manufacturer's sheet

The numbers for what and from where? There are multiple units listed with multiple specs for each. It would be helpful if you could specify what table entry you are using and for which model. Let's look at the specs for the MSZ-GE09NA which are on page 12 of the brochure:

At 17F it states:

Rated Capacity: 6600BTU Rated Total Input: 700W

A 700W resistance heater would generate

700 x 3.41 =3D 2387 BTU The heat pump is generating 6600 BTU Meaning the heat pump is generating 2.7 times more heat at 17F outside temp than you would get with a resistance heater using the same amount of electricity.

From the same specs, it gives the capacity at 47F as

10,900 BTU. The capacity at 17F is 6,600 which means you're still getting 60% of the heat that you get at 47F.

Now the part that I don't understand is the graph earlier in the brochure that shows capacity staying constant all the way down to 10F. I think we agree that sounds like marketing BS of some kind, given that it does not have resistive heating.

[trader4]

There we have it folks. The usual KRW tactic. Try to now change the discussion into something else. Art stated:

" But, it shows that you are almost getting the same amount of heat as you would if it were a resistive heater. "

There was no qualification of temperature. Now, having been wrong, just as I predicted, you try to weasel away by now adding "at some low temperatures" into it.

Perhaps you should look at the data sheet for the Mitsubishi units under discussion instead of embarrasing yourself further. Per the analysis I showed in my last reply to Art, at 17F, the MSZ-GE09NA is producing 2.7 times the heat that you would get from a resistance heater. That's pretty impressive performance in cold temps.

And it sure doesn't jive with:

"" But, it shows that you are almost getting the same amount of heat as you would if it were a resistive heater. "

YOU are the one that agreed with the analysis that the heat pump only generates about as much heat as an equivalent resistance heater. YOU were agreeing that it only moves the same amount of heat as it uses. Now of course, you're trying to weasle away, by adding "at some low temps" At 17F it's still generating

2.7 times the heat you'd get from a resistance heater. Even at 5F it's still generating far more heat than a resistance heater.

And as predicted, instead of being a man and admitting your error, you've quickly resorted to name calling.

[krw]

Wong, liar. The discussion *was* about operation and efficiencies at lower temperatures.

...at low temperatures.

You really are an idiot. That's what the discussion was about. What a stupid liar.

[trader4]

Show me where Art gave a temp that his statment applied to. Typically YOU would be the one to jump all over something like that, because it's open ended, generally not true, and meaningless without specifying what temps you are talking about.

He now says it was at 17F that his analysis was done. Well, per the Mitstubishi data sheet, which you obviously have not even bothered to read, page 12, at 17F you get 2.7 times the heat output that you would with a resistance heater. That is not about the same amount of heat as a resistance heater, it's 2.7 times greater. Art made a mistake. YOU agreed with the analysis which is TOTALLY WRONG and instead of admit it, as usual, you start the name calling. Try reading the datasheet instead of embarrassing yourself.

YOU agreed with a faulty analysis that didn't even menti > >" But, it shows that you are almost getting the same amount

It's a very broad indictment of heat pumps. And what that faulty analysis was based on, I still don't know because Art didn't say what numbers he was using. You obviously have not done any analysis. I did. And per the Mistubishi data sheet specs, at 17F your're getting 2.7 times the heat out of their heat pump unit than you do with a resistance heater. Now for most people, 17F is a pretty cold climate. And per the Mitusbishi brochure, it's still nowhere near a resistance heater all the way down to 5F.