ᐅ Trench Collector Ground Source Heat Pump or Air Source Heat Pump?
Created on: 1 Mar 2015 10:25
L
Legurit
Hello everyone,
We had our first meeting with the builder yesterday. He quickly dismissed the heating topic since there is no gas connection but gave us some contact addresses.
The house has roughly 190 m² (2,045 sq ft) of living space and a heating demand of 6,600 kWh/year, or about 6 kW heating load.
So far, we have planned to install a ground-source heat pump with a horizontal collector, but the builder rightly pointed out that he would prefer some maneuvering space around the house. In the pink forum, there is a community advocating for DIY horizontal collectors, saying that the trenches including materials could be done for around €2,000. Including the heat pump gross price of €10,000, that would be €12,000 total. An air-source heat pump would cost at least that much for the unit alone.
Unfortunately, we are already a bit overwhelmed with the house planning and are not sure if we would trust ourselves to do the DIY installation. Does anyone have experience with the costs when contracting out the trenching and pipe laying?
As for consumption, we found a factor of about 1.5. So the air-source heat pump would be around 50% more expensive to operate than the ground-source heat pump, but we wouldn’t have to dig (in absolute terms, about €180 per year). We are also unsure whether having a photovoltaic system would be beneficial or not (we are skeptical).
Thanks for your experiences and advice.
We had our first meeting with the builder yesterday. He quickly dismissed the heating topic since there is no gas connection but gave us some contact addresses.
The house has roughly 190 m² (2,045 sq ft) of living space and a heating demand of 6,600 kWh/year, or about 6 kW heating load.
So far, we have planned to install a ground-source heat pump with a horizontal collector, but the builder rightly pointed out that he would prefer some maneuvering space around the house. In the pink forum, there is a community advocating for DIY horizontal collectors, saying that the trenches including materials could be done for around €2,000. Including the heat pump gross price of €10,000, that would be €12,000 total. An air-source heat pump would cost at least that much for the unit alone.
Unfortunately, we are already a bit overwhelmed with the house planning and are not sure if we would trust ourselves to do the DIY installation. Does anyone have experience with the costs when contracting out the trenching and pipe laying?
As for consumption, we found a factor of about 1.5. So the air-source heat pump would be around 50% more expensive to operate than the ground-source heat pump, but we wouldn’t have to dig (in absolute terms, about €180 per year). We are also unsure whether having a photovoltaic system would be beneficial or not (we are skeptical).
Thanks for your experiences and advice.
Yes, it was actually available, but our heating engineer informed us about geocollect. Just google it, I’m not allowed to link it here. It sounds interesting and would at least involve installation by the heating technician.
I wouldn’t agree with the statement that a ground-source heat pump is ALWAYS better than an air-to-water heat pump. Take a look at the real-world performance of the Vitocal 300a. Some models achieve a seasonal performance factor above 4.5. I have also seen ground-source heat pumps that don’t reach that value. Nowadays, the difference isn’t that significant. The much higher upfront cost for drilling probably won’t pay off during the system’s lifetime for just a 0.5 lower seasonal performance factor. I find trench collectors interesting but too uncertain. That’s why I’m now considering geocollect. However, in the end, I think I will save the money and install photovoltaic panels on the roof instead. You get more return that way.
I wouldn’t agree with the statement that a ground-source heat pump is ALWAYS better than an air-to-water heat pump. Take a look at the real-world performance of the Vitocal 300a. Some models achieve a seasonal performance factor above 4.5. I have also seen ground-source heat pumps that don’t reach that value. Nowadays, the difference isn’t that significant. The much higher upfront cost for drilling probably won’t pay off during the system’s lifetime for just a 0.5 lower seasonal performance factor. I find trench collectors interesting but too uncertain. That’s why I’m now considering geocollect. However, in the end, I think I will save the money and install photovoltaic panels on the roof instead. You get more return that way.
S
Sebastian793 Jun 2016 14:27Ground source heat pumps that perform worse than an air-source heat pump are simply poorly configured or the entire system is not balanced. An annual performance factor above 4.5 with air-source heat pumps? Even the BAFA (Federal Office for Economic Affairs and Export Control) doesn’t achieve that with its official calculation – you also need to consider the location of the users and whether they have additional heating sources.
So, initially hard to believe...
So, initially hard to believe...
tabtab schrieb:
What happened to all the brine-to-water heat pumps here? Could you share your experiences and annual performance factors? I used mine to warm up the screed during winter, so I don't have reliable data on normal consumption yet. I also haven't had time to properly analyze the consumption for domestic hot water.
S
Sebastian793 Jun 2016 14:37Oh yes, during the screed heating, I had an annual performance factor of 1.9
Sebastian79 schrieb:
Ground source heat pumps that perform worse than an air-source unit are simply poorly configured or the overall system is not right. A seasonal performance factor above 4.5 for air-source units? Even BAFA doesn't achieve that with their calculations - you also have to consider where people live and whether they have any additional heat sources.
So, that’s hard to believe at first...Then, for example, take a look at the Ochsner Eagle – it is rated from the factory with a COP of 4.5.
S
Sebastian793 Jun 2016 15:01Could it be that you are confusing COP and annual performance factor?
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