ᐅ Company Lüumel, trench collector (horizontal ground heat exchanger)
Created on: 3 Dec 2015 06:58
D
daytona
Hello everyone,
does anyone have general experience, both positive and negative, with the company Lüumel from Coswig?
I currently have an offer for a heat pump with a horizontal ground loop. I have already read quite a bit about this online. I would be interested in hearing about your experiences here as well. Unfortunately, my offer is not very detailed, so I will get in touch with the company. But maybe some of you here in the forum can help in advance:
How does the seasonal performance factor (SPF) or energy consumption compare to other heat pump systems?
Have you had a simulation or calculation of the SPF done?
What is the impact or buildability of the buried pipes in the garden, for example regarding load-bearing or drive-over capacity?
Is a heat meter absolutely necessary?
What are the pros and cons of a horizontal ground loop? (I know this is a very general question)
does anyone have general experience, both positive and negative, with the company Lüumel from Coswig?
I currently have an offer for a heat pump with a horizontal ground loop. I have already read quite a bit about this online. I would be interested in hearing about your experiences here as well. Unfortunately, my offer is not very detailed, so I will get in touch with the company. But maybe some of you here in the forum can help in advance:
How does the seasonal performance factor (SPF) or energy consumption compare to other heat pump systems?
Have you had a simulation or calculation of the SPF done?
What is the impact or buildability of the buried pipes in the garden, for example regarding load-bearing or drive-over capacity?
Is a heat meter absolutely necessary?
What are the pros and cons of a horizontal ground loop? (I know this is a very general question)
1. Our heat pump (ground source/borehole) is relatively quiet. It is located in the basement with the door open and the stairwell open, and is only audible in the evening when it is really quiet (children in bed, TV off, etc.). When the room door is closed, you cannot hear it anymore.
2. For about 240m² (2,583 sq ft) of space (including 80m² (861 sq ft) in the basement, which is within the insulated building envelope, with not all rooms actively heated there, but always kept above 16°C (61°F)), I have used just under 10,000 kWh of electricity for heating and hot water over the past 4.5 years. Of that, about 2,000 kWh were used for the screed heating program.
In addition, there was a heating maintenance visit a week ago – the first one – everything is fine (so no special maintenance costs such as replacement parts or similar).
2. For about 240m² (2,583 sq ft) of space (including 80m² (861 sq ft) in the basement, which is within the insulated building envelope, with not all rooms actively heated there, but always kept above 16°C (61°F)), I have used just under 10,000 kWh of electricity for heating and hot water over the past 4.5 years. Of that, about 2,000 kWh were used for the screed heating program.
In addition, there was a heating maintenance visit a week ago – the first one – everything is fine (so no special maintenance costs such as replacement parts or similar).
KfW70 Energy Saving Ordinance 2009 according to the calculation before construction. Somewhere in the forum there are details; the house was subsequently built with somewhat higher-quality materials (for example, significantly better insulating window frames, slightly thicker basement insulation, insulated roof AND attic…), so technically it might also meet the KfW55+ standard.
The electricity consumption was measured with a calibrated electricity meter.
For heat quantity measurement, I use the system’s internal meter; the heating values correspond to the heat losses of the building I calculated (using the actual building components), so it should be fairly accurate. However, I have not provided a separate heat quantity figure.
Furthermore, I have very carefully adjusted the heating curve and other parameters of the heating system to the house (for example, although individual room controllers are installed, all of them are deactivated without any loss of comfort, meaning room temperature fluctuations during the heating months are less than 0.5 degrees Celsius (0.9°F)).
The electricity consumption was measured with a calibrated electricity meter.
For heat quantity measurement, I use the system’s internal meter; the heating values correspond to the heat losses of the building I calculated (using the actual building components), so it should be fairly accurate. However, I have not provided a separate heat quantity figure.
Furthermore, I have very carefully adjusted the heating curve and other parameters of the heating system to the house (for example, although individual room controllers are installed, all of them are deactivated without any loss of comfort, meaning room temperature fluctuations during the heating months are less than 0.5 degrees Celsius (0.9°F)).
We have 140 m² (1,507 ft²), with half of the rooms maintained at around 22-23°C (72-73°F) and the rest at 20°C (68°F). Since we frequently experience malfunctions, we always need to activate the heating cartridge. Not for long periods, maybe about a week with the heating cartridge. Each technician adjusts the heating differently. Who could I contact for good advice on this and to reduce our electricity consumption? 8,000 kWh per year is clearly too much for us.
I adjusted the heating curve similar to Saruss and deactivated most of the individual room controllers (IRCs).
By default, Lüumel probably sets a slope of 0.3 and an offset of +2° during the day and 0° at night for the heating curve, possibly including a comfort boost of 1-2° at selected times.
We had the IRCs set as limiting elements throughout. My idea was to lower the heating curve a bit to save energy. I started with the rooms that have the highest heat demand (living room and bathroom). With the IRCs fully open and the valves on the heating manifold fully open, it was too warm for me in winter. So, I reduced the slope to 0.2° and shifted the heating curve slightly upwards. Then, especially during the transition period, it was a bit too cool, so I moved the heating curve further up for day and night until the two warmest rooms were comfortable. Our target temperature was reached at +5°.
After that, I fully opened the IRCs in the other rooms. In most rooms, it was naturally too warm. So, I adjusted the flow rates on the valves in the heating manifold to ensure that the temperature in these rooms was correct even with fully open IRCs.
Since the valves are now always open and therefore continuously powered, I removed the automatic controllers from the heating manifold and set the IRCs in the rooms to zero. This way, no electricity is consumed.
The IRC in the guest room remains in operation, as adjustments there need to be made depending on use.
A small tip: write down what you change and how it affects things, and don’t adjust too much at once. This is not something you can finish in 14 days; for us, it took a good two years.
By default, Lüumel probably sets a slope of 0.3 and an offset of +2° during the day and 0° at night for the heating curve, possibly including a comfort boost of 1-2° at selected times.
We had the IRCs set as limiting elements throughout. My idea was to lower the heating curve a bit to save energy. I started with the rooms that have the highest heat demand (living room and bathroom). With the IRCs fully open and the valves on the heating manifold fully open, it was too warm for me in winter. So, I reduced the slope to 0.2° and shifted the heating curve slightly upwards. Then, especially during the transition period, it was a bit too cool, so I moved the heating curve further up for day and night until the two warmest rooms were comfortable. Our target temperature was reached at +5°.
After that, I fully opened the IRCs in the other rooms. In most rooms, it was naturally too warm. So, I adjusted the flow rates on the valves in the heating manifold to ensure that the temperature in these rooms was correct even with fully open IRCs.
Since the valves are now always open and therefore continuously powered, I removed the automatic controllers from the heating manifold and set the IRCs in the rooms to zero. This way, no electricity is consumed.
The IRC in the guest room remains in operation, as adjustments there need to be made depending on use.
A small tip: write down what you change and how it affects things, and don’t adjust too much at once. This is not something you can finish in 14 days; for us, it took a good two years.
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