Hello everyone,
I am new to the forum and hope to get some help evaluating a pellet heating system offer.
My wife and I, together with my parents, have purchased a house with approximately 400 sq meters (4300 sq ft) of living space. Currently, there is a 30-year-old oil heating system. The house is also 30 years old. An energy consultant inspected the entire house and recommended replacing the oil heating with a pellet heating system supported by solar heating.
The consultant prepared the following offer:
-- ST PARADIGMA wood pellet boiler Pelletti III, 30 kW nominal heat output, 9–30 kW
-- Pellet storage bunker
-- ST PARADIGMA Aqua package for hot water generation
-- PARADIGMA solar station STAqua single-loop solar station
-- Underfloor heating in the bathroom
All together costing 42,972.05 euros
From this, a grant from BAFA of about 7,800 euros will be deducted
So the actual costs would be around 35,000 euros
Originally, the heating installer’s first offer was around 49,000 euros (before the BAFA subsidy)
I would really appreciate if someone could help me assess this offer. I am also open to completely different ideas :-)
Thank you all in advance!!!!
Best regards ;-)
I am new to the forum and hope to get some help evaluating a pellet heating system offer.
My wife and I, together with my parents, have purchased a house with approximately 400 sq meters (4300 sq ft) of living space. Currently, there is a 30-year-old oil heating system. The house is also 30 years old. An energy consultant inspected the entire house and recommended replacing the oil heating with a pellet heating system supported by solar heating.
The consultant prepared the following offer:
-- ST PARADIGMA wood pellet boiler Pelletti III, 30 kW nominal heat output, 9–30 kW
-- Pellet storage bunker
-- ST PARADIGMA Aqua package for hot water generation
-- PARADIGMA solar station STAqua single-loop solar station
-- Underfloor heating in the bathroom
All together costing 42,972.05 euros
From this, a grant from BAFA of about 7,800 euros will be deducted
So the actual costs would be around 35,000 euros
Originally, the heating installer’s first offer was around 49,000 euros (before the BAFA subsidy)
I would really appreciate if someone could help me assess this offer. I am also open to completely different ideas :-)
Thank you all in advance!!!!
Best regards ;-)
Capitano schrieb:
....The energy consultant doesn’t care which manufacturer or heating technology is used. Initially, we favored the brine-to-water heat pump, but unfortunately the offers were not very good. “Good” is relative if you look only at the initial investment. Additionally, for example, with a brine-to-water heat pump, cost-effective trench or surface collectors are possible if you can or want to contribute your own labor. This can significantly reduce the costs for heat source development.
Heat pumps generally perform best with small temperature differences between the source and the heat sink. This usually means large heating surfaces on the heat sink side, such as underfloor heating or radiators.
Conventional heat generators (gas condensing boilers, pellets, wood, oil) typically achieve system efficiency factors greater than 1, more or less clearly depending on the system size.
In contrast, heat pumps can utilize approximately 70–80% free environmental energy, depending on the type and sizing.
I would not assume that such potential should simply be given away unchecked ;-) Superficiality rarely leads to an optimal final result!
Best regards
Has a heat load calculation ever been done to verify whether the 30 kW rating actually applies? Just because the old heating system was 30 kW doesn’t mean that’s correct.
We had a heating engineer visit who wanted to sell us a 25 kW boiler for 180 m2 (1937 sq ft) – his reasoning was: 1 kW per 10 m2 (108 sq ft) of living space always fits – plus hot water.
However, our heating load is actually 6 kW, not 18 kW. That would have been a costly mistake. Hot water is not produced by the boiler but by a domestic hot water heat pump. Solar panels on the roof don’t make sense – and the roof is already fully equipped with photovoltaic panels.
Now we have a “suitable” pellet boiler that modulates between 3 and 15 kW – smaller units were not available – for 3,600 euros. Quite a price difference already. It’s also subsidized by BAFA, which will reduce the price further. Installation costs are 1,000 euros, as this boiler can be connected like a stove. Plus 800 euros for a 500 L (132 gallon) buffer tank.
For the transitional periods, we use a split air conditioning unit, which can cool in summer and heat in spring and autumn using heat pump technology, also eligible for KfW funding – 3.5 kW for 600 euros. The domestic hot water heat pump costs around the same, about 700 euros. Installation is extra; I don’t do that myself, as it’s quite complicated. However, installation is not hugely expensive, and you have the assurance that a professional has done the job.
After deducting the 2,900 euros BAFA subsidy, the total cost for heating, hot water, and cooling for our house is about 4,500 euros, including installation (excluding small parts like stovepipes).
We had a heating engineer visit who wanted to sell us a 25 kW boiler for 180 m2 (1937 sq ft) – his reasoning was: 1 kW per 10 m2 (108 sq ft) of living space always fits – plus hot water.
However, our heating load is actually 6 kW, not 18 kW. That would have been a costly mistake. Hot water is not produced by the boiler but by a domestic hot water heat pump. Solar panels on the roof don’t make sense – and the roof is already fully equipped with photovoltaic panels.
Now we have a “suitable” pellet boiler that modulates between 3 and 15 kW – smaller units were not available – for 3,600 euros. Quite a price difference already. It’s also subsidized by BAFA, which will reduce the price further. Installation costs are 1,000 euros, as this boiler can be connected like a stove. Plus 800 euros for a 500 L (132 gallon) buffer tank.
For the transitional periods, we use a split air conditioning unit, which can cool in summer and heat in spring and autumn using heat pump technology, also eligible for KfW funding – 3.5 kW for 600 euros. The domestic hot water heat pump costs around the same, about 700 euros. Installation is extra; I don’t do that myself, as it’s quite complicated. However, installation is not hugely expensive, and you have the assurance that a professional has done the job.
After deducting the 2,900 euros BAFA subsidy, the total cost for heating, hot water, and cooling for our house is about 4,500 euros, including installation (excluding small parts like stovepipes).
Elina schrieb:
Has a heating load calculation ever been done to verify if those 30 kW are actually accurate? Just because the old heating system was 30 kW doesn’t mean it’s the right size... Correct! Elina schrieb:
...and the roof is already fully covered with photovoltaic panels. A heat pump would have been ideal as the primary heat source. It offers a high share of self-consumption, which you should have calculated in advance. I have designed heat pump systems combined with photovoltaic installations where heating, cooling, and hot water achieve a net-zero energy balance over the year!
Best regards.
We had the calculations done, but it didn’t work out. The photovoltaic system produces the least amount of energy exactly when the heating demand is at its highest. In December and January, it generates only about 1–6 kWh per day.
This means that running a heat pump with photovoltaic power in winter wouldn’t have been feasible. The expensive household electricity, which is not getting any cheaper, would have pushed costs even higher. The special heat pump tariff here is only slightly cheaper, but it would have required an additional meter. In the end, it was simply too expensive.
The heat pump subsidy from BAFA is a joke compared to the pellet heating subsidy (which is twice as high as for heat pumps), but the costs including installation for heat pumps are much higher. Heat pump quotes started at around 10,000 euros, while pellets cost less than half of that.
The ducted mini-split unit runs during the transitional seasons using surplus photovoltaic energy, as there is still enough yield then. And when it gets really cold, the boiler kicks in, which also achieves a decent level of utilization.
A heat pump powered entirely by photovoltaic energy only works with large systems; ours has just 7 kWp. With a daily expected yield of 4 kWh in January — which is often not even reached, with many days producing 2 kWh or less — I honestly don’t believe a heat pump can keep the house warm without drawing additional electricity. If you have 20 kWp or more, it might be a different story.
This means that running a heat pump with photovoltaic power in winter wouldn’t have been feasible. The expensive household electricity, which is not getting any cheaper, would have pushed costs even higher. The special heat pump tariff here is only slightly cheaper, but it would have required an additional meter. In the end, it was simply too expensive.
The heat pump subsidy from BAFA is a joke compared to the pellet heating subsidy (which is twice as high as for heat pumps), but the costs including installation for heat pumps are much higher. Heat pump quotes started at around 10,000 euros, while pellets cost less than half of that.
The ducted mini-split unit runs during the transitional seasons using surplus photovoltaic energy, as there is still enough yield then. And when it gets really cold, the boiler kicks in, which also achieves a decent level of utilization.
A heat pump powered entirely by photovoltaic energy only works with large systems; ours has just 7 kWp. With a daily expected yield of 4 kWh in January — which is often not even reached, with many days producing 2 kWh or less — I honestly don’t believe a heat pump can keep the house warm without drawing additional electricity. If you have 20 kWp or more, it might be a different story.
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