In a great number of countries an increasing part of the housing stock is in Multi Family Buildings, often high rise, in which the efficient generation of sanitary hot water can be a challenge.
Based on the sum of all losses, decentralized solutions are the best solution, where collective solutions for hot water distribution should be avoided whenever possible!
In a number of applications collective solutions are however the only option, like in hospitals, care homes for the elderly and hotels.
On the subject of “best system design” with regard to energy-efficient hot water supply, a number of reports and articles are noteworthy, such as:
- Bernhard Vetsch – Warmwasserbereitstellung mittels Wärmepumpen in Mehrfamilienhaus
- Stadt Wien – Mehr Familien Häuser und Wohnhausanlagen Warmwasser
- COLMAC – HPWH-Piping-Arrangements
- M. Hoeschele – Multifamily Heat Pump Water Heater Evaluation
- AFPAC – La Pompe à Chaleur – Des solutions pour l’eau chaude sanitaire en habitat collectif.
An important challenge is retrofit, where a few fine examples show the way how to do it. The ECBCS Annex 50 published some Case Studies already in 2011. In 2019 Heat pump retrofit Strategies for Multi Family Buildings has been published by Steven Winter Associates, Inc. as a set of guidelines with a special focus on DHW.
Individual solutions for DHW can be found, especially in new buildings with a low space heating demand or in renovated existing buildings.
Especially collective solutions high temperature heat pumps are in demand in order to avoid legionella and/or give a high comfort to the individual end-user.
Gas Fired Solutions
Gas fired heat pumps have the advantage of a lower load on the network and a smaller source, being a perfect solution in many cases.