Calorex 510 Heat pump question

[jugglerb]

Hi There,
Looking for some advice please.

I have a Calorex 510 heat pump purchased second hand heating an 18ft round above ground pool 52" deep.
I use a 3/4HP (0.75) sand filter/pump.

Im seeing approx 0.5c to 1.0c temp difference between inlet and outlet to the pool whilst the heat pump is running. Is this correct for this size of heat pump or should I be seeing more of an increase than this?

Many thanks.

[Gary]

The temperature difference tells you absolutely nothing about how well the heat pump is working.

[Gary]

To expand on this:

A smaller pump would give you a greater difference, but it would be heating far less water.

A larger pump would give you a smaller difference, but would be heating much more water.

The end result would be about the same. If anything, greater flow with smaller difference might give you a little more heating... but then it would take more energy to run the larger pump.

[Gary]

Typically, the installer would adjust the water flow valve to get about 3C temperature difference. This is generally considered to give an optimum trade off between heat output and energy usage... and again, it says nothing about how well the heat pump is operating.

[jugglerb]

thanks Gary. the pool is up to 27.5c after 3 days of running so must be working ok.
Not cheap to run though I rekon about 8 quid a day.

[Gary]

The best thing you can do for your system is to keep the airflow portion clean (clean fan blades, clean coil, etc.). For efficient operation it needs good airflow.

[CHIZEL010]

The 510 has an automatic bypass assembly on it, so the water flow is always correct flowing through the machine

[jdunc2301]

if your looking to heat the pool to 30'C you might find it hard, in our experience with calorex HP on above ground pools its not good.

Where did you buy it second hand?

[jugglerb]

Hi, ebay.
I can get the pool to 29c depending on the sunshine level, admittedly im trying to only run the pump for 7 hrs a day while im on 0.04p per kwh (economy 7), gets a bit expensive to run at 0.13 per kwh otherwise, If I ran the pump all day long it would probably maintain 30c. Pool has a decent solar cover.
Today being overcast/cooler its struggling to get to 27-28.