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Posted

Good day

I recently installed a 5.4 kw ITS heatpump to an existing 200 l geyser. Both outside and next to each other.

According to the spec sheet the heatpump is supposed to draw 1.26 kw when running. However, according to my Effergy meter it uses about 1.8 to 2 kw when running. Ambient temp outside about 25 degC.

Is this normal? Can someone with the same heatpump maybe check and confirm the power usage.

Seems like a very low COP.

 

Posted (edited)

Hi @Leonb

I have a severon 5kw heat pump outside with the geyser in the ceiling and pipes insulated.

I've set it to heat up water for morning showers before I get up. It seems to use quite closer to specs according to the inverter stats. Here are 2 screen shots. Temperature outside when it came on was between 16 and 18 degrees celcius. It does use slightly more electricity when it pushes the water to 58 celcius. 

What Temperature do you have it set to? I'm sure 60 degrees celcius will use more electricity. 

Screenshot_20220403-121954_ShinePhone.jpg

Screenshot_20220403-122037_ShinePhone.jpg

Edited by Buyeye
Posted
1 hour ago, Leonb said:

Good day

I recently installed a 5.4 kw ITS heatpump to an existing 200 l geyser. Both outside and next to each other.

According to the spec sheet the heatpump is supposed to draw 1.26 kw when running. However, according to my Effergy meter it uses about 1.8 to 2 kw when running. Ambient temp outside about 25 degC.

Is this normal? Can someone with the same heatpump maybe check and confirm the power usage.

Seems like a very low COP.

 

That efergy does not measure kW, it can only measure kVA. So don't expect it to be very accurate when measuring the usage of an induction motor, where the power factor can range from 0.2-0.9 depending on load and motor.

Posted
21 hours ago, Leonb said:

Good day

I recently installed a 5.4 kw ITS heatpump to an existing 200 l geyser. Both outside and next to each other.

According to the spec sheet the heatpump is supposed to draw 1.26 kw when running. However, according to my Effergy meter it uses about 1.8 to 2 kw when running. Ambient temp outside about 25 degC.

Is this normal? Can someone with the same heatpump maybe check and confirm the power usage.

Seems like a very low COP.

 

So this is exactly what I am waiting to see on mine. I can only tell for sure once it is on my essential loads. I have the same heat pump.

My installer said that on startup it will draw 1.8kw for about 45seconds. Or no more than 1minute. After that it reduces to 1.3kw odd for the remainder of the cycle. I am ok with the initial spike, but I do need it to drop to the specified 1.3kw afterwards. 

Posted
21 hours ago, Buyeye said:

I've set it to heat up water for morning showers before I get up. It seems to use quite closer to specs according to the inverter stats. Here are 2 screen shots. Temperature outside when it came on was between 16 and 18 degrees celcius. It does use slightly more electricity when it pushes the water to 58 celcius. 

What Temperature do you have it set to? I'm sure 60 degrees celcius will use more electricity. 

Try going downwards. As long as you have to use the cold water tap when you're taking a shower you are over heating.

This is a subjective matter. What some folks call a good hot shower puts me in fear of blistering.

It will obviously take more power to heat to higher temperatures, but what is the RIGHT temperature is a personal preference.

Posted
13 minutes ago, Bobster said:

Try going downwards. As long as you have to use the cold water tap when you're taking a shower you are over heating.

This is a subjective matter. What some folks call a good hot shower puts me in fear of blistering.

It will obviously take more power to heat to higher temperatures, but what is the RIGHT temperature is a personal preference.

Quite right. In my household i really struggle to find this balance. I have to temper the shower with cold water. Or rather.. i open the hot to take the edge off the cold.. my Mrs doesnt open the cold at all. And sometimes indicates it isnt hot enough.. its a slippery slope. My heat pump is set to 53degC at bottom of tank. I assume it is between 55 and 60degC at the outlet.

Posted (edited)
On 2022/04/03 at 12:11 PM, Leonb said:

Good day

I recently installed a 5.4 kw ITS heatpump to an existing 200 l geyser. Both outside and next to each other.

According to the spec sheet the heatpump is supposed to draw 1.26 kw when running. However, according to my Effergy meter it uses about 1.8 to 2 kw when running. Ambient temp outside about 25 degC.

Is this normal? Can someone with the same heatpump maybe check and confirm the power usage.

Seems like a very low COP.

 

I think the easy way to measure the actual COP is to measure the power used to heat the geyser. An element geyser would use 233 Wh per degree increase for a 200 L geyser. 175 Wh per degree for a 150 L geyser. Working from basics it will be 1.167 Wh per degree per litre water.

Although I have a 9 year old 4.7 kW ITS mine is fitted with an inverter drive and it starts at a low 300 W and then takes 2 min to ramp up to 1.5 kW. It used to be 1.2 kW for the 1st 5 years but the power used has crept up over the years. My power used is measured with a CT to a multi display power meter which gives instant Volts, current and power. It then has a cumulative measurement for power used. This meter also shows the same power used as my Sonoff pow R2.

Even after 9 years the COP varies from 2 to 3. It does take a while to see the 1st few degrees increase in temp but then a steady rise.

Edited by Scorp007
Corrected power unit
Posted

So I discussed this with ITS and according to them the 1.8 KW at the "default" temperature range is normal. Mine is set to start when bottom of geyser temp goes below 50 degC. It will then continue to heat until bottom temperature is at 53 degC. At this point the heat pump outlet temp into top of geyser is around 57 to 58 degC.

According to ITS the 1.2 KW input will only be seen when heating the system from cold, e.g. when starting up. I will check this at some point  by letting whole system cool down for a day or so.

But it seems for "normal" operation, it operates closer to the max input spec (2 kw input in the case of the 5.4 kw unit).

Posted
17 hours ago, Leonb said:

So I discussed this with ITS and according to them the 1.8 KW at the "default" temperature range is normal. Mine is set to start when bottom of geyser temp goes below 50 degC. It will then continue to heat until bottom temperature is at 53 degC. At this point the heat pump outlet temp into top of geyser is around 57 to 58 degC.

According to ITS the 1.2 KW input will only be seen when heating the system from cold, e.g. when starting up. I will check this at some point  by letting whole system cool down for a day or so.

But it seems for "normal" operation, it operates closer to the max input spec (2 kw input in the case of the 5.4 kw unit).

Is your 1.8kw for the totality of the cycle? Or at start up only? 

Posted
18 hours ago, Leonb said:

So I discussed this with ITS and according to them the 1.8 KW at the "default" temperature range is normal. Mine is set to start when bottom of geyser temp goes below 50 degC. It will then continue to heat until bottom temperature is at 53 degC. At this point the heat pump outlet temp into top of geyser is around 57 to 58 degC.

According to ITS the 1.2 KW input will only be seen when heating the system from cold, e.g. when starting up. I will check this at some point  by letting whole system cool down for a day or so.

But it seems for "normal" operation, it operates closer to the max input spec (2 kw input in the case of the 5.4 kw unit).

Hi can I check how you get your water to 50 celcius. Do you not use the timer? 

I was encouraged to use the timer so that my heat pump is not always on to prolong its life.

Posted
2 minutes ago, Buyeye said:

Hi can I check how you get your water to 50 celcius. Do you not use the timer? 

I was encouraged to use the timer so that my heat pump is not always on to prolong its life.

The heat pump kicks in automatically when the bottom temp in geyser drops below 50 degC.

Posted
Just now, Leonb said:

The heat pump kicks in automatically when the bottom temp in geyser drops below 50 degC.

Even at night when you are asleep and noone needs hot water?

Posted
1 minute ago, Buyeye said:

Even at night when you are asleep and noone needs hot water?

Yes, that is the current setup. 

It was only installed last week, so I'm still planning on optimising the times. Currently it is running as the normal element was prior to installing heatpump so I can compare like to like. As it looks currently, the saving (compared to electrical element) is closer to 50% (COP of 2) than 66% (COP of 3). 

 

Posted
1 hour ago, Leonb said:

Yes, that is the current setup. 

It was only installed last week, so I'm still planning on optimising the times. Currently it is running as the normal element was prior to installing heatpump so I can compare like to like. As it looks currently, the saving (compared to electrical element) is closer to 50% (COP of 2) than 66% (COP of 3). 

 

Ok I was already using a timer with the resistive element.

Posted (edited)

Mine is also on a timer. Has been since installation. I just received my bill and saw a significant reduction of 120units in my useage (and it was only installed for 9 days of the 28 day cycle). This bodes well so far

Edit. 120.unit reduction from last months bill. Not accurate i know.. but its what i have to work from whilst it is on non essential load.

Edited by GTP
Posted
2 hours ago, Leonb said:

Yes, that is the current setup. 

It was only installed last week, so I'm still planning on optimising the times. Currently it is running as the normal element was prior to installing heatpump so I can compare like to like. As it looks currently, the saving (compared to electrical element) is closer to 50% (COP of 2) than 66% (COP of 3). 

 

That does seem low. Are you considerimg the running time as well in the calc? I find my unit on its timers runs for no more than 1h30 odd a day. 

Posted
1 hour ago, GTP said:

That does seem low. Are you considerimg the running time as well in the calc? I find my unit on its timers runs for no more than 1h30 odd a day. 

Yes. I'm comparing the previous number of kwh per day used by geyser element vs heatpump. But it has only been a week, and also a bit colder this week. I'll keep on monitoring for a while.

Posted
8 hours ago, Buyeye said:

Even at night when you are asleep and noone needs hot water?

Any thermostat system is mean to be powered up when the temp is below the set point. Because it will switch on just like an element geyser the timer function is great not to keep on switching on during the night.

I only switch my heat pump on for 2h a day.

@Leonb

The COP is closely correlated to ambient temp.  It is now colder so the COP will move to 3 in summer.

  • 1 month later...
Posted

So I received the attached data from ITS on the power use (KW) at different inlet/outlet temperatures. With the loading valve system installed, the heat pump pretty much operates in the 48 C to 60 C region 90%+ of the time, so the heat pump will use around 1.8 kW for the full duration of operation. Only the first few minutes when it pre-charges the water initially, it will be using lower Kw. 

So the 1.26 Kw on spec sheet is slightly misleading. Although spec sheet does state a max of 2 kw, a "reasonable man" would expect normal operation around 1.26 kw, and maybe spikes to 2 kw for short period. But it pretty much runs an max the whole time. 

The new b-class geysers with the additional ports does allow for the heatpump installation without the loading valve, which will let the heat pump operate over a wider temperature range. However, I'm not sure what the impact of this is on energy use (kWh). Will it still use the same amount of kWh to heat the water, just spread over longer period, or use less kwh (assuming the same water temperature setting for both cases). ITS says it will use the same.??

That being said I still save quite a lot even with the loading valve setup. Looking at historic data, at least ~60% less kWh.

R410a ITS5.4HD (1).pdf

  • 1 month later...
Posted (edited)

I just got my ITS 5.4 moved onto essential load as well. It ran for 15 odd minutes and I can confirm it ran between 1.8 and 2kw

Edit. Ok. I have now seen the heat pump run in all its iterations now that I can visualise consumption on the inverter.

So for the startup and initial cycle, the unit fires up and runs at aroun 1450w, slowly creeping up to around 1800w. This is over the course of some 40mins.

The evening cycles when my family does their bath routine, the unit runs at 1700w and creeps up to around 2000w.. 

In all, it runs just under 2 hours a day in this weather.

I remember in March it ran for around 90mins. 

I did bump up the temperature by 3 degC as the Mrs was not happy. In summer I will drop it by 5 degC. So in summary. I guess the really big savings will be seen in the warmer months when the COP is greater. In winter, i am still seeing a 60% odd reduction, and I put it down to running at almost half the power, and for such a short period of time.

I do think the specification jargon is on the misleading side.. i acknowledge that the label says max power is 2000w.. i didnt expect that most of the power is in the upper range though.

Edited by GTP
  • 1 year later...
Posted
On 2022/04/04 at 10:17 AM, Bobster. said:

Try going downwards. As long as you have to use the cold water tap when you're taking a shower you are over heating.

This is a subjective matter. What some folks call a good hot shower puts me in fear of blistering.

It will obviously take more power to heat to higher temperatures, but what is the RIGHT temperature is a personal preference.

This is the quote of the week! I've never thought of it like this:
 

Quote

As long as you have to use the cold water tap when you're taking a shower you are over heating.

The only issue is the bath now! 🙂 

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