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Help optimising ASHP settings

samforward
Posts: 3 Newbie

in Heat pumps
We've recently had a Samsung Gen 6 ASHP with 200L cylinder by Joule. It was part of a grant including solar and insulation. The installers were in and out very quickly and more or less shrugged their shoulders when asked questions about settings, and the more I've been digging into the forums the more I've been feeling lost!
- It's a small 2 bedroom terraced 1990s house with 1 zone set up, 6 radiators. No underfloor heating, fairly well insulated now.
- It may be an oversized unit, they used a smaller unit on 2 neighbors houses of the same size.
- 6 panels on the roof, no battery
- Octopus Agile so cheap electric apart from 4-7pm
- First 2 days have used 8kwh, and generated 22-24kwh based on the 'energy consumption' section of the panel.
1. Water Law - it was set up as:
201* Outdoor temp
Low (left of screen): 20C
High (right of screen): 0C
202* Water temp
Low (left of screen): 41C
High (right of screen): 55C
My understanding from the above is - at 20C, the water temp for the radiators will be limited to 41, and at 0C will target 55C as a max, with a line in between. Is that correct?
I'm not sure how I would go about optimizing this for my house, or if it's already perfect. What steps could I take to test this?
I've scheduled:
- DHW heats to 45C at 3pm, when solar will be strongest. (4pm is when the high electric costs would kick in).
- Heating is:
7am - 18C
13:30 - 19.5C (making use of solar and higher outside air temp to warm the house
16:00 - 18C (this is peak electric rates, so trying to avoid spending here, hoping that residual heat will keep it warm enough to avoid cycling until after 7.
22:00 - 15C - we like it cold at night.
Questions:
- Is my schedule the correct way to make the most of cheap solar during the day and avoid peak tariffs between 4-7pm?
- How can I optimise my water law settings?
- The ASHP is fairly loud and cycling a lot, is there a way to reduce number of cycles per hour?
- What does quiet mode actually do? It didn't seem to change anything.
- Many others are sharing lots more data from their set-ups, I'm not sure how I can see this info?
Thank you in advance.
- It's a small 2 bedroom terraced 1990s house with 1 zone set up, 6 radiators. No underfloor heating, fairly well insulated now.
- It may be an oversized unit, they used a smaller unit on 2 neighbors houses of the same size.
- 6 panels on the roof, no battery
- Octopus Agile so cheap electric apart from 4-7pm
- First 2 days have used 8kwh, and generated 22-24kwh based on the 'energy consumption' section of the panel.
1. Water Law - it was set up as:
201* Outdoor temp
Low (left of screen): 20C
High (right of screen): 0C
202* Water temp
Low (left of screen): 41C
High (right of screen): 55C
My understanding from the above is - at 20C, the water temp for the radiators will be limited to 41, and at 0C will target 55C as a max, with a line in between. Is that correct?
I'm not sure how I would go about optimizing this for my house, or if it's already perfect. What steps could I take to test this?
I've scheduled:
- DHW heats to 45C at 3pm, when solar will be strongest. (4pm is when the high electric costs would kick in).
- Heating is:
7am - 18C
13:30 - 19.5C (making use of solar and higher outside air temp to warm the house
16:00 - 18C (this is peak electric rates, so trying to avoid spending here, hoping that residual heat will keep it warm enough to avoid cycling until after 7.
22:00 - 15C - we like it cold at night.
Questions:
- Is my schedule the correct way to make the most of cheap solar during the day and avoid peak tariffs between 4-7pm?
- How can I optimise my water law settings?
- The ASHP is fairly loud and cycling a lot, is there a way to reduce number of cycles per hour?
- What does quiet mode actually do? It didn't seem to change anything.
- Many others are sharing lots more data from their set-ups, I'm not sure how I can see this info?
Thank you in advance.
0
Comments
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samforward said:
1. Water Law - it was set up as:
201* Outdoor temp
Low (left of screen): 20C
High (right of screen): 0C
202* Water temp
Low (left of screen): 41C
High (right of screen): 55C
My understanding from the above is - at 20C, the water temp for the radiators will be limited to 41, and at 0C will target 55C as a max, with a line in between. Is that correct?samforward said:
I'm not sure how I would go about optimizing this for my house, or if it's already perfect. What steps could I take to test this?samforward said:
- Is my schedule the correct way to make the most of cheap solar during the day and avoid peak tariffs between 4-7pm?samforward said:
- is there a way to reduce number of cycles per hour?
My heat pump does not report its heat energy output so others may be better placed to answer questions about that.
Reed1 -
Disable operation under "Water Law" and use a fixed output temperature.
I'm surprised that modern ASHPs aren't smart enough to adjust water temperature constantly based on how successfully heating a space, it seems a simple thing to program. But I'm probably understanding it wrong.0 -
samforward said: I'm surprised that modern ASHPs aren't smart enough to adjust water temperature constantly based on how successfully heating a space, it seems a simple thing to program. But I'm probably understanding it wrong.If the heat pump is OpenTherm compatible (MBus is another), then the smart thermostat can tell the HP what flow temperature is needed. Some heat pumps have inverter control to reduce the flow (modulating down the heat output) and thus avoid constant cycling.Heat pumps are getting smarter as the technology improves, but they also need smarter controls to get the best performance. It also takes time to tweak the settings to improve efficiency.
Her courage will change the world.
Treasure the moments that you have. Savour them for as long as you can for they will never come back again.0 -
samforward said:Disable operation under "Water Law" and use a fixed output temperature.
I'm surprised that modern ASHPs aren't smart enough to adjust water temperature constantly based on how successfully heating a space, it seems a simple thing to program. But I'm probably understanding it wrong.
The "smart" capability that you suggest is called "Load Compensation". A gas boiler with an Opentherm controller could do that but AFAIK almost no heat pumps are Opentherm capable. But if you are using the manufacturer's own controller it may have a Load Compensation capability. I don't know enough about Samsung ASHPs to advise.Reed0 -
Oh, and the cycling may be because your heat pump cannot modulate down low enough to run continuously. This will happen if the outside temperature is too high. But if the heat pump is more powerful then necessary then the minimum power it is capable of may be higher too making cycling more likely..Reed0
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If they've fitted thermostatic radiator valves (which they shouldn't with a heat pump) then open them fully. You want as much water circulating, at all times, as possible, to stand a chance of getting a decent SCOP.
This thread is of interest to me as I'll be getting a Samsung 5kW fitted, under the ECO4 scheme, in the next few weeks. Having looked at the spec sheets, that the installer sent, the operating instructions look pretty incomprehensible, on paper at least. I'm hoping once I've got a few actual buttons to press they might become clearer.0 -
Netexporter said:If they've fitted thermostatic radiator valves (which they shouldn't with a heat pump) then open them fully. You want as much water circulating, at all times, as possible, to stand a chance of getting a decent SCOP.
This thread is of interest to me as I'll be getting a Samsung 5kW fitted, under the ECO4 scheme, in the next few weeks. Having looked at the spec sheets, that the installer sent, the operating instructions look pretty incomprehensible, on paper at least. I'm hoping once I've got a few actual buttons to press they might become clearer.
That's good advice, I had closed the valve to the spare room radiator, but now realising I'm in the old gas boiler mindset.
It does seem like ignoring the massive amount of information, the only real variables are weather compensation and DHW temp, and any scheduling you choose to make for heating the rads or DHW at a favorable (cheap) time.0 -
Unfortunately, the minimum SCOP target allowed under MCS regulations is relatively low, basically it should match the cost of running a gas boiler, so under grant-aided schemes the installers haven't got much incentive to optimise the design.
As I was going to install a heat-pump, anyway, before I discovered I was eligible for ECO4, I'm just going to shake the system down, to make sure it is working, even if not optimally, then I'll spend the money I haven't had to lay out on underfloor heating, as I'm upgrading the house anyway. With luck I'll have a SCOP of over 5, then.0 -
I think it's mandatory for any new heating system installation to include thermostatic valves on the radiators. If the radiators are all correctly balanced then TRVs are unnecessary but your installers are unlikely to have taken the time to ensure fully correct balancing so TRVs act as a workaround.
Heat pumps like to work with a minimum volume of water but your system may have a buffer or volumizer tank to ensure this, in which case it doesn't matter if you or a TRV turn radiators off
But if you turn off the radiator in the spare room but the spare room is not well-insulated from the rest of the house then the remaining radiators will have to work harder and this could reduce your system efficiency. This would apply to both gas boilers and heat pumps but the effect would be more significant for heat pumps. Reduced efficiency means increased running cost and this could possibly outweigh the saving from reducing the average temperature of the house.Reed1 -
samforward said:We've recently had a Samsung Gen 6 ASHP with 200L cylinder by Joule. It was part of a grant including solar and insulation. The installers were in and out very quickly and more or less shrugged their shoulders when asked questions about settings, and the more I've been digging into the forums the more I've been feeling lost!
- It's a small 2 bedroom terraced 1990s house with 1 zone set up, 6 radiators. No underfloor heating, fairly well insulated now.
- It may be an oversized unit, they used a smaller unit on 2 neighbors houses of the same size.
- 6 panels on the roof, no battery
- Octopus Agile so cheap electric apart from 4-7pm
- First 2 days have used 8kwh, and generated 22-24kwh based on the 'energy consumption' section of the panel.
1. Water Law - it was set up as:
201* Outdoor temp
Low (left of screen): 20C
High (right of screen): 0C
202* Water temp
Low (left of screen): 41C
High (right of screen): 55C
My understanding from the above is - at 20C, the water temp for the radiators will be limited to 41, and at 0C will target 55C as a max, with a line in between. Is that correct?
I'm not sure how I would go about optimizing this for my house, or if it's already perfect. What steps could I take to test this?
I've scheduled:
- DHW heats to 45C at 3pm, when solar will be strongest. (4pm is when the high electric costs would kick in).
- Heating is:
7am - 18C
13:30 - 19.5C (making use of solar and higher outside air temp to warm the house
16:00 - 18C (this is peak electric rates, so trying to avoid spending here, hoping that residual heat will keep it warm enough to avoid cycling until after 7.
22:00 - 15C - we like it cold at night.
Questions:
- Is my schedule the correct way to make the most of cheap solar during the day and avoid peak tariffs between 4-7pm?
- How can I optimise my water law settings?
- The ASHP is fairly loud and cycling a lot, is there a way to reduce number of cycles per hour?
- What does quiet mode actually do? It didn't seem to change anything.
- Many others are sharing lots more data from their set-ups, I'm not sure how I can see this info?
Thank you in advance.
If you want to configure it you can set the setpoint at its highest (e.g. 25 degrees) to always call for heat and then adjust the weather compensation curve (by reducing the flow temperature at the cold end of the curve) to as low as it will go whilst still maintaining your desired internal temperature and not overshooting on a cold winter day.
Before you do that you should set 2091/92/93 to 3 as if it's set to 1 it allows the flow temp setpoint to overshoot if there's a call for heat.0
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