With 90,000 overnight stays per year, the Maritim in Hanover is one of the most visited hotels in Germany.

The unusual architecture spectacularly symbolises an aeroplane with its outspread wings - in keeping with its location at Hanover-Langenhagen airport.

The most efficient building on the site.
At a consumption of 4,250 MWh/a, the energy costs of the hotel are in six figures and thus make up an above average
proportion of the operating costs
. The technical director of the Maritim
Group, Dieter Pfaff, recognised the immense potential of high-efficiency pumping technology early on.

Put through its paces.
Together with the Institute for Heating and Air-Conditioning Technology at Brunswick/Wolfenbüttel college, a study was implemented to empirically record the savings possible by replacing a standard pump with a high-efficiency pump of the same nominal diameter. It also aimed to determine other possibilities for increasing energy efficiency. To this end, measurements were taken for several heating circuits in the hotel in climatically similar periods. As well as the operating electricity, the study also recorded the average operating hours over the year
and the progression of the differential temperatures of the feed and return.

The results speak for themselves.

• A simple 1:1 replacement generates a saving of 65 %.
• The Δp-v mode adds an extra saving of 15 %.
• The measured temperatures of the feed and
  return show further potential for saving power. Excessive return temperatures suggested that smaller pumps would be sufficient.
• Test runs with "smaller pumps" confirm it: there is no loss of heating comfort
  due to smaller nominal diameters and there are further savings of up to 11 %.

Complete replacement considered.
All in all, savings of up to 93 % in the electrical power consumption of the pumps were recorded. A result that far exceeded expectations. As the figure currently stands at 150,000 kWh/a, a complete replacement of the over 80 pumps with Wilo-Stratos could reduce the total power costs by a five-figure sum (in euros) or by nearly 5%. The replacement of the pumps is being seriously considered, especially as replacing the pumps on a grand scale can be carried out more reasonably
than replacing the single pump. "The Maritim Group is seriously considering this seminal step," says Dieter Pfaff, "because a suitable replacement can pay for itself within three years."

 

Maritim, Hanover

Planning: Reinhardt & Sander GmbH, Bad Salzuflen

Operator: Michael Pfaff