Groundwater heat pump replaces existing oil heating system
The commercial building with production hall and offices (usable area: approx. 2,700 m2) dates from 1972. Previously, the rented building was supplied with heat for heating via an oil heater.
The tenant, aqua concept GmbH, attaches great importance to environmental sustainability and has been certified according to DIN ISO 14000 since 2010 and has been CO2-neutral since 2016 by offsetting CO2 emissions. The goal of aqua-concept GmbH is to reduce CO2 emissions by 10 % annually. Therefore, the heat supply to commercial buildings should be as environmentally friendly, cost-efficient and CO2-minimized as possible. The company commissioned goodmen energy GmbH to plan the transformation of the heat supply.
An intensive examination of the site as well as an actual and target analysis was carried out. The decision was then made to use a groundwater heat pump. After submitting a funding application to BAFA and its approval of 35 %, there was a longer waiting time due to the drilling company's limited capacity. The drilling and installation of the heat pump finally took place in January 2024, almost 3 years after the energy planning and despite the winter cold, very quickly within two days. 137 liters per minute can be drawn from the 16 meter deep groundwater well.
Details:
A 95% decarbonized heat supply has been successfully implemented in an unrenovated existing building that is over 50 years old. The power supply for the heat pump comes from green electricity from the grid and from the property's own PV systems on the roof.
How was this achieved? Based on the consumption data analysis, an annual consumption value of 18,800 liters of heating oil was determined. This corresponds to a heat quantity of around 188 MWh. However, this heat requirement was able to be corrected significantly downwards in the course of the inventory analysis. The reason: Almost half (!) of the previous heating oil consumption was wasted unnoticed in poorly insulated heating circulation pipes with high flow temperatures, which had led to immense heat losses.
By avoiding these heating losses, improving day/night reduction of the entire system and lower heating flow temperatures, it has been possible to reduce heat consumption in a normal winter to around 90 MWh. The heating requirement can be covered by the new heat pump system not only to 80%, as initially aimed for, but even to around 95%.
Facility-Data:
HP power: 50 kW
Buffer storage: 1,000 liters (due to lack of space, a larger buffer storage is not possible)
CO2 savings: approx. 57 tons/year
To cover the remaining 5% as peak load and as back-up, the oil boiler remains in standby mode.
An important factor for the low consumption is also the careful monitoring of the new hybrid system: through the optimized heating control, the efficiency of the system has been optimized and ensured in the long term. aqua concept GmbH offers this heating monitoring as a service for its customers and has therefore carried it out independently. The annual performance factor could be optimized to over 3.
The Building Energy Act (GEG) also requires testing and optimization of heat pump systems in §60a (https://www.gesetze-im-internet.de/geg/__60a.html), as heat pumps deliver poor annual performance figures if set incorrectly and thus a cause unnecessarily high power consumption, so that the overall profitability also deteriorates seriously. With this operator obligation, the legislature provides precautionary protection against unpleasant surprises with excessive electricity bills.
