Hi, I just got heat pumps last spring and am now trying to figure out how to most efficiently use them . I have 2 units on my first floor, an 18k in the living room and 12k in the kitchen. I have been using the 18k mainly for now, as it's not that cold out yet. I have been monitoring the current draw of the heat pump at various times to get an idea of how much the compressor is ramping up or down. I have seen anywhere from 2.2 amps or so to maybe 6.6 when running full out and then it has gone up to like 9-10 when coming out of a defrost cycle one time.
One thing that really confused me the other day is that it appeared that it was short cycling (it was in the high 50s outside two days in a row and the house probably had built up a large amount of heat. I left in the morning with it set on high (3 bars) fan speed. It is set to 76F, which results in a 70-72F temperature in my room most of the time. It was getting warm out and I noticed it kept climbing past 78F (a temperature sensor is mounted up on the unit outside of where the unit's sensor is located so I can gauge what it is seeing as the room temp.) It will usually level off at 78F when it is colder outside, presumably by ramping down the compressor some. However, since it was so warm out and the house had been so warm for a few days, the compressor output it was using was making it go past 78 to 79F. Once it hits 79F up at the ceiling sensor, it will short cycle. I went down to test the current and it was pulling maybe 4.2 amps (~1000 watts.) Theoretically, it should be able to put out only 2.1-2.3 amps (500ish watts) or so on low compressor mode. I am wondering why it was refusing to ramp down further than 4.2 amps. Is it because I have the fan on manual mode instead of AUTO mode? Is it trying to make sure the temperature of the air coming out of the unit is a certain minimum temperature? I've rarely seen the current less than like 4.2 amps. I did see it that low one time when it was on AUTO mode with a very low fan speed, so that made me think that it should be able to go below 4.2 amps. I assume it is trying to keep the air leaving the unit at a certain temp and will gladly short cycle over and over to do that rather than drop the temp coming out down (by ramping down to a lower compressor setting), which would allow it to keep running on high fan speed and not short cycle? I think I would prefer to avoid short cycling and have a lower compressor output, as short cycling drives me crazy and is a waste of energy)
One thing that really confused me the other day is that it appeared that it was short cycling (it was in the high 50s outside two days in a row and the house probably had built up a large amount of heat. I left in the morning with it set on high (3 bars) fan speed. It is set to 76F, which results in a 70-72F temperature in my room most of the time. It was getting warm out and I noticed it kept climbing past 78F (a temperature sensor is mounted up on the unit outside of where the unit's sensor is located so I can gauge what it is seeing as the room temp.) It will usually level off at 78F when it is colder outside, presumably by ramping down the compressor some. However, since it was so warm out and the house had been so warm for a few days, the compressor output it was using was making it go past 78 to 79F. Once it hits 79F up at the ceiling sensor, it will short cycle. I went down to test the current and it was pulling maybe 4.2 amps (~1000 watts.) Theoretically, it should be able to put out only 2.1-2.3 amps (500ish watts) or so on low compressor mode. I am wondering why it was refusing to ramp down further than 4.2 amps. Is it because I have the fan on manual mode instead of AUTO mode? Is it trying to make sure the temperature of the air coming out of the unit is a certain minimum temperature? I've rarely seen the current less than like 4.2 amps. I did see it that low one time when it was on AUTO mode with a very low fan speed, so that made me think that it should be able to go below 4.2 amps. I assume it is trying to keep the air leaving the unit at a certain temp and will gladly short cycle over and over to do that rather than drop the temp coming out down (by ramping down to a lower compressor setting), which would allow it to keep running on high fan speed and not short cycle? I think I would prefer to avoid short cycling and have a lower compressor output, as short cycling drives me crazy and is a waste of energy)
