This is a typical simple heat pump hydraulic circuit. The heat pump is isolated from the heating system by a thermal break, in this case a low loss header. The heat pump is either in Tank or Heating mode. In tank mode the three way valve sends hot water to the hot water cylinder. In heating mode it sends hot water to the thermal break. The pump in the radiator circuit takes heated water from the break to the heat emitters.
Typically with a heat pump a Renewable Energy company is brought in to install a heat pump to connect onto a n existing heating system, or one which another plumber is responsible for. If there is then a problem with the heating then it is very easy for the Renewables company to blame the plumber and the plumber to insist that the problem is with the Renewables company. At its simplest a thermal break delineates between the responsibility of the two disciplines. The Renewables company ensures hot water is supplied to the thermal break and the plumber is responsible for distributing it around the house.
That's not all that a thermal break does. A heat pump requires significantly greater water flow than a boiler, at least double and maybe four or six times the quantity. If it is starved of water then it will nuisance trip at best and become damaged at worst. A thermal break ensures that the heat pump gets enough water flow.
Low Loss Header
A low loss header is a small piece of very large diameter pipe into which we take the heat pump flow pipe into the top and the return back from the bottom. It gives a slow moving reservoir of hot water. The heating system then draws from this reservoir the water that it needs. It has an air ventilation point at the top and a drain point at the bottom and silt or other contaminants naturally collect in the base for removal at servicing.
Our range of low loss headers are a proven and tested design and are pre insulated. They are also available with manifolds and pump sets to manage more complex system designs and reduce time on site.
The manifold set above has, from left to right,
- A simple pump set with shut off valves, a filter, a circulation pump and flow and return thermostats.
- An Under Floor heating pump set with an additional mixing valve
- A heating circuit pump set with a three way valve and differential pressure valve
The heat production side can have just a heat pump, multiple heat pumps and a mixture of heat sources.
A buffer tank is like an enlarged low loss header and offers a thermal storage facility as well as being a thermal break.
When the system is in heating mode then the heat pump heats the water in the buffer tank for the heating system to draw off. When the heat pump goes into tank mode then there is a buffer of hot water for the heating system to use.
We have a range of buffer vessels available with very high levels of insulation ranging from 80 to 305 litres.