# Thread: Heat Pump Quiz Question

1. Professional Member
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A heat pump is operating in the heating mode. The lower the outside air temperature, the

a. more efficient the heat pump.
b. higher the SEER rating.
c. higher the compression ratio.
d. lower the balance point.

2. my guess is C

3. I'll go with C also.

4. Thinking out loud here...if I remember correctly, the closer together the suction and discharge pressures are on a compressor, the lower number there will be on the compression ratio.

So, with a heat pump in heat mode, say it's running a suction pressure around 50 psia, and head is up around 270 psia, that's 5.4:1 compression ratio, whereas if same heat pump was in cooling mode on a hot day running same head pressure psia but suction around 84 psia, that's 3.2:1 comp ratio.

I will also pick "C" as being correct.

5. I'll agree with everyone else - C

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You can eliminate the first two from facts as we already know which is the farther north you go with a heat pump, which is a colder climate and would give you the same scenario being described, the less efficient it is.

The 3 rd answer is the right answer as already described. The farther apart the pressures are, the higher the compression ratio.

So “C”, all you have to do is eliminate the bad guys.

[Edited by madeinusa on 08-06-2005 at 08:22 PM]

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Well Im no HVAC Pro so I will just guess...

I dont think it could be A because a H/P removes heat from the air outside and puts it inside...

I dont think it could be B because it would seem the lower the temp outside, the less efficent the system would be.

Not entierly sure what a balence point is but if it's the temperature of when not to run the electric strips it should not change.

So the only one left is C. And I have no idea what the compression ratio is (Im just a guy who is really interested in HVAC)

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I vote for C

Heat pumps in heat mode don't have a SEER rating, It's an HSPF or COP rating.

9. C.

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D.
heat pump capacity will decrease and heat loss will increase.

(lower balance point)

11. D lower the balance point

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DDDDDDDDD

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Originally posted by shophound
Thinking out loud here...if I remember correctly, the closer together the suction and discharge pressures are on a compressor, the lower number there will be on the compression ratio.

So, with a heat pump in heat mode, say it's running a suction pressure around 50 psia, and head is up around 270 psia, that's 5.4:1 compression ratio, whereas if same heat pump was in cooling mode on a hot day running same head pressure psia but suction around 84 psia, that's 3.2:1 comp ratio.

I will also pick "C" as being correct.
I think you might have the correct answer,S'hound,but "your thinking out loud" shows you drifted off to the cooling mode...read the question again please.

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