Heat Pumps: Myths and Facts

Heat pumps and heat grids are among the central strategies for climate neutrality
in existing buildings. Heat pumps in particular are repeatedly confronted with outdated prejudices.
We counter these with a series on fundamental questions and answers from proven experts.

Series “Heat Pumps in Existing Buildings”

BLOG POST SERIES | 10 Feb. 2021

How can heat pumps be used in existing buildings? Do all existing buildings have to be extensively retrofitted first?

Are heat pumps able to guarantee sufficiently high flow temperatures required? Can they achieve sensible efficiency values in existing buildings? And is this operation actually ecological?

In order to provide well-founded answers to these and other questions and to create a good basis for future decision-making, we have commissioned the Fraunhofer Institute for Solar Energy Systems with a blog post series on “Heat Pumps in Existing Buildings”.

The twelve blog posts will be published weekly on the Fraunhofer-ISE science blog. They are based on the knowledge and experience gained from almost twenty years of heat pump research at Fraunhofer-ISE. In the blog posts, the various arguments against heat pumps in existing buildings will be analyzed and contrasted with various research results.

EPISODE 3 | 24 Feb. 2021
Does a house have to be renovated first in order to install a heat pump?
Clearly, the less energy needed to create a comfortable indoor climate, the better. That’s why renovation measures to reduce heating energy demand always make sense. This applies to all heating systems. Fortunately, houses do not have to be extensively renovated before installing a heat pump. This post explains why, in the vast majority of cases, a good heat pump solution can also be implemented in unrenovated (or slightly refurbished) buildings.

Blog post on the Fraunhofer-ISE website

The next post in our series we will take a closer look at the results of our field test of heat pumps in existing buildings.

EPISODE 2 | 17 Feb. 2021
Heat pumps in existing buildings: Are heat pumps able to deliver sufficiently high temperatures in the heating circuit?
When discussing the possible use of heat pumps in existing buildings, the main counter-argument is the very high temperature of the heating circuit on which they are based. This episode argues: Why the maximum required temperature is not the decisive factor.

Blog post on the Fraunhofer-ISE website