How to control the temperature zonally, heating the house with a heat pump? - ENGO

How to control the temperature zonally, heating the house with a heat pump?

11/06/22

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The basics of a heat pump

A heat pump works on the principle of thermodynamic conversion. It forces heat from the ground, water or air into heated rooms in a building, and possibly also into a DHW (hot water supply) system. The heat pump alternately compresses and expands the working medium (a gas with a low evaporating temperature). When it evaporates, it takes heat from the lower source (the surroundings of the house); when it compresses, the temperature rises and the heat produced is pumped to the upper source (the destination; the heating system of the house).

Heat pumps will power radiators, underfloor heating, and fan coils. However, controlling a heat pump raises concerns about the safety of the unit. Today we explain how to make sure that doesn’t happen.

Zone control of a heat pump – can it be done?

Zone control is based on installing thermostats in each room. This is convenient, economical and comfortable, as it allows you to adjust the temperature to the function of the rooms and the needs of the household. However, the heat pump has a rather long start-up. It needs time to heat up the medium taken from the environment (e.g. air, groundwater). In contrast, some rooms heat up quickly. This is where the problem arises. For example, if you want to heat a small room (e.g. a bathroom or a closet) by underfloor heating, you have to switch the heat pump on and off in a short period of time. This can cause damage. So it is considered that zonal control of the heat pump is risky for the unit. On the other hand, giving it up is neither useful nor cost-effective. It is really worthwhile to equip the heat pump with an automatic control (zone control), because it will make the heating unit produce less heat, and this will bring us great savings.

How to apply zone control to the heat pump?

This is why we do not control the heat pump directly, but rather the distribution of the water from the buffer (e.g. by a circulation pump), which stores the heat it produces. The control algorithms do not interfere in any way with the function of the heat pump itself! This makes it safe. This allows you to enjoy all the benefits of zone control without any problems.

Here is a schematic illustration of the process:

Lets review the benefits of zone heating control:

  • separate room temperature control
  • temperature adapted to the function of the room
  • limitation of non-ecological overloading states
  • no overheating or cooling of the interior
  • optimal energy consumption
  • saving on heating fuel
  • saving of money
  • protection of nature
  • greater comfort in everyday life

There may be some questions, especially in recent months, about the price of electricity needed to control a heat pump. They are getting higher, and electricity still powers most such pumps. Heat pumps run on electricity. However, we should remember that heat pumps use renewable resources, which are free and unlimited in nature. This gives a different perspective on the generated costs. The issue of obtaining electricity is also important.

To sum up…

No matter what heating appliance you choose, you need zone control. And if you choose heat pumps, you are doing a great favour for nature, because it is a solution for the future. Heat pumps do not produce smoke, ash or other pollutants that penetrate the environment.

It reduces low emission. However – for zone control to be safe for the heat pump – the heating system must be equipped with a buffer tank (buffer). The automatic control system manages the heat stored in the buffer; it distributes it to the individual heating loops.

So basically the control of the heat pump is at the level of the water intake from the buffer, not the water itself. And this is precisely the key to success. In this case, zonal temperature management becomes as efficient as with coal, gas or electric heating. There is nothing to fear.