## The heat pump and the old building## When looking at the statistics on heat pumps in old buildings, it must also be remembered that the switch to heat pumps was made for economic reasons.With a new car, you know there's 0.8 mm of sheet steel. But on the old car, there could be 0.6 mm of rust and 0.2 mm of sheet steel. It is the same with thermal insulation. The wall construction gives u=0.15 W/m²/K. But what about the old building? The calculated value is u=0.5, but what if this is only 0.75 due to moisture? Furthermore, the air exchange rate could be significantly higher than assumed?Researching this alone in a refurbishment project would be a lot of work. Let's assume that the heat requirement is calculated at 10 kW and that the radiators can bring this 10 kW into the house at a flow temperature of 55°. But the thermal insulation is worse, the air exchange is higher, 15 kW heat requirement to maintain 20 ° at -10 ° outside. What now? Even if the heat pump would create the 15 kW heat, the radiators can only deliver 10 kW heat at the maximum achievable flow temperature. This is then only enough for about 12 ° in the house. If it is only 0° outside, then 20° can be maintained with 55° flow temperature. But compared to the assumption of 6.67 kW, 10 kW heat must be generated. But compared to the assumption of 43° flow temperature at 0° outside temperature it is 55°. This lowers the coefficient of performance from 2.67 to 2.17. Instead of 6.67 kW divided by 2.67 = 2.5 kW electricity, it is then 10 kW divided by 2.17 = 4.61 kW. Freezing in your own home during a cold snap and using 85% more electricity than predicted can make a heat pump buyer extremely sour.
Reports have appeared in some mass media that the party headquarters of the Green Party is being rebuilt since 2019, a heat pump should be put into operation in the fall of 2023, cost € 5 million. It is not possible to find out how many square meters of usable space this building has. But even with 1,500 m² of usable space, the costs would be higher than to build a new building. Such a thing can afford a rich party, but how should this go with a pensioner? With old buildings with 150 kWh/m²/a heat requirement the heating costs would be also with 10 cent per kWh only 15 € per m² and year. But these are not 0 after the renovation, but maybe 50 kWh/m²/a heat, which cost 20 kWh electricity with the heat pump. With 30 cent/kWh electricity that makes 6€. That leaves only 9€/m²/a for the credit installment. Even with a 30-year credit period, this only allows 150 € of renovation costs per square meter to be financed. Where is there an offer to thermally renovate a 100 m² old building for 15,000 €, down from 150 to 50 kWh/m² annual demand and install a heat pump, replace radiators? That is the profitability limit, where the homeowner just gets out cost-neutral. Unfortunately, the floor space of the Green Party headquarters is not known, but even at 2,000 m² this would be 2,500 €/m². Let's calculate that for 40,000,000 people times 40 m² of living space. Makes 4.000.000.000 €. If you can't count the zeros, that's 4 trillion €. Couldn't the money be used more efficiently? Sure, but cost optimization and economic considerations are completely alien to the Greens. For them, money is only something that can be taken from the taxpayer. Cost optimization on the part of the provider can only be expected if the customer has the freedom to decide. What's the point of cost optimization if the state forces customers to sign up by law? For the providers, this is like a land of milk and honey, where roast pigeons fly into their mouths.
There are, of course, studies of heat pumps in real-world use. Here is a study on the page of the Salzburg provincial government: However, it is highly doubtful that the Greens are aware of these studies. When looking at the statistics on heat pumps in old buildings, it must also be remembered that the switch to heat pumps was made for economic reasons. With a conversion obligation, these statistics could turn out even worse.
Quote from this page: "Admittedly, the photovoltaic system hardly provides any surplus electrical energy during the heating season, for this reason the degree of self-use of a photovoltaic system by the heat pump increases only slightly." Of course, this is true for houses with little photovoltaics and high electricity demand for the heat pump. But even in December in far northern Berlin, 44 kW of photovoltaics still manage to completely supply the GEMINI next generation house. The objective is to achieve with the air-source heat pump a better AWP (annual performance factor) than can otherwise only be achieved with the ground-source heat pump. Here is the technical concept for this:
Extremely low flow temperature:
A club member donates his membership fee to the club and is happy if the club is successful. If not, I have supported a good cause. A shareholder acquires shares in a stock corporation. If the AG is successful, his shares are worth much more. In the case of GEMINI next Generation AG, his reward for supporting a good cause. As a shareholder, employee or homebuyer, you will also become part of the countermovement against many negative developments in our society that are detrimental to our survival. A new shareholder said "I with my very modest investment", but 4,000 times 1,000 € is also 4 million for all investments until the opening of the settlement in Unken as a starting point for worldwide expansion. Only the Annual General Meeting can resolve the major capital increases, but here is what the Executive Board and Supervisory Board can resolve. The new capital stock is used to perfect the documents for the larger planned capital increases. Here are the details. |