HEAT PUMPS

An important fact to note before any retrofit of a heat pump takes place is that the installation of Tadpole will improve the performance of a heat pump, including air to water heat pumps considerably. The primary temperature may improve to such an extent that the use of oversize radiators, which is a common practice, may not be necessary.

It is important to discuss this with the client. Some social landlords wish to run the whole installation at a lower temperature (35-40°C) to maximise on the improvement in C.O.P. Therefore it will be necessary to use oversize radiators, or an underfloor heating system.

To get the best performance of Tadpole with ground source heat pumps, test and unsolicited reports tell us that there needs to be two Tadpoles installed. One in the ground loop (which will produce an increase in the C.O.P of around 8%) and the other in the primary or heating system. Together, they will produce an unprecedented improvement in the performance of the heat pump, which in turn will reduce the running costs, improve the overall C.O.P of the heat pump, improve the comfort level of the property and reduce maintenance issues. The primary water, which will now be inert, will stay clear. The consequence of this is that the primary system will be running at day one levels of efficiency even after many years service.

Under normal conditions, Tadpole is installed upstream of the circulation pump and any "S" or "Y" plan. The action of the pump "sucking" through the Tadpole actually speeds up the process of de-aeration. A heat pump, be it air to water, or ground source, has generally a greater pumping velocity of 48 to 50 litres/minute. This causes the vortex to become almost vertical and parallel, which would have the effect of sucking air in to the system. When tadpole is installed on the positive side of the circulation pump, (Fig. 3) it cannot create the same air problem. It takes a little longer to form the vortex, but the end result is the same. The system should become quieter. It will also become more efficient, using up to 29% less electricity if two Tadpoles are installed in a ground source heat pump.

In some cases, the primary system of a heat pump has a slower pumping velocity of around 25 litres/minute. This is due in part to the heating system design. If it is known that the pumping velocity is such, then Tadpole may be installed upstream of the circulation pump.

We would recommend the fitting of Gate Valves on either side of Tadpole to facilitate the replacement or maintenance of the Air Vent if required. Alternatively a Shut Off Valve can be supplied for Tadpole at an extra cost.