RESOL is Europe’s market leader for solar thermal control technology. The company has more than 30 years of experience in the development and production of solar thermal controllers. RESOL is well known for their innovations which have changed solar market standards in the past.
But still - not all Solar Thermal Systems are working as efficient as they could. Some of them are even operating without any energy yield, due to poor installation and/or maintenance. The Problem is that end-users do not receive any notice of failure or inefficiency because the back up boiler provides the heat required.
Therefore RESOL was actively looking for a reliable and cost effective way to measure the heat output of a solar thermal system. The purpose was to develop the most innovative solar-pumpstation with an integrated heatmeter and further intelligent features.
The Grundfos Solution
By measuring and monitoring all relevant parameters of a Solar System (e.g. flow, pressure, supply and return temperature) the heat-output can easily be calculated.
All these measurements can be done by 2 Grundfos Direct Sensors ™ . RESOL is convinced that these cost-effective sensors can make an important contribution providing:
> a “real” function by heat metering
> improved efficiency
> greater comfort
> enhanced safety & ease of use
For these purposes the following sensors have been developed and fully integrated: Grundfos VFD 1-12 and RPD 0-10
Over the course of the project we had to learn, how to bend physical rules in fluid dynamics, especially when it comes to cold glycol water in the low-flow area. Two further years of hard R&D work and a redesign of the vortex-insert 1-12 was necessary to achieve the breakthrough.
Also RESOL has made an important further development in this period of time. The “FlowCon Sensor” was patented as the installation of collector and storage sensors is not required anymore. Two Grundfos Direct Sensors ™ in the solar-pump station are taking over to ensure the functionality and a maximum solar yield.
This very innovative solar pump station has been launched at ISH 2009 and awarded at the INTERSOLAR 2009.
RESOL has also comprehensive knowledge and experiences in control technology for freshwater modules. The customised controllers are also using Grundfos Direct Sensors ™ as the combined measurement of flow and temperature ensures a maximum in Domestic hot water comfort.
Meanwhile the heat metering (for Solar Thermal Systems and Heatpumps) based on Grundfos Direct Sensors ™ has officially been approved the German federal office for economics and export control (BAFA).