Split and monobloc heat pumps: what is the difference?

Split and monobloc heat pumps: what is the difference in construction?

In short: the key difference - with further consequences - is related to the construction of monobloc and split heat pumps. And yes:

•  monobloc pumps are those in which the entire refrigeration system is placed in one hermetic unit;
•  split pumps are those in which the refrigeration system is split between the outdoor and indoor units. The compressor, evaporator and expansion valve are located outside. Inside - a heat exchanger, i.e. a condenser, and a circulation pump.

What is the difference between monobloc and split pumps?

Let's take a look at the most important aspects of the consequences of differences in the construction of individual pumps.

Installation of split and monobloc heat pumps 

For mono pumps, the entire refrigeration unit is factory-assembled and fully hermetic. This guarantees 100% tightness of the device and makes its installation easier and does not require special F-gas licenses. The connection is made only on the water side.

This is not the case with a split device. Here , part of the refrigeration system is already carried out during assembly work - it is necessary, among others, to connect both parts of the unit with wires. Therefore, there is a greater risk of losing the tightness of the system. The installer must also have an F-gas license. 

Cena

An investment in a split pump is usually associated with a smaller financial investment - in the context of the purchase of the device itself. However, there are additional costs associated with the need to meet formal requirements, i.e. the obligation to establish the so-called product data sheet and have regular leak checks carried out by professionals. This is a must if the power of such a pump exceeds 10 kW.

Monobloc pumps are more expensive "to start", but later they do not generate additional costs - there is no need to create a product card or perform technical inspections.

Acoustics

Monobloc devices are well insulated acoustically and thermally. This adversely affects their higher cost, but at the same time increases the comfort of use. You don't have to worry that the system will be too noisy, and thus you don't have to look for a place to install the equipment away from the "night" zone of the house.

Split pumps may run a little louder.

Safety and operational reliability

In the case of split pumps, in which part of the refrigeration system is created at the installation stage, there is a greater risk of leakage. When installing them, there are also more moments when you can make a mistake, resulting in frustrating and costly breakdowns.

On the other hand, devices of this type are better protected against power outages . If the split pump runs out of power, there is no risk that the system's wires will freeze and the device will be damaged. This is due to the fact that the heat exchanger is mounted inside.

Monobloc pumps are fully assembled at the factory, so there is no risk of leaking the refrigeration system, and there are fewer moments where you can make a mistake during assembly (although mistakes can still happen on the water side!). However, the actual risk of freezing the wires when the power supply is cut off is higher. To protect against this, special protection is used - first of all, an insulated water connection is created using pre-insulated water pipes. They are laid approx. 20 cm below the level of ground frost. You can also make an emergency power supply - so that when the power supply is cut off, you can keep the heat pump running.

Energetic efficiency

In terms of performance, split and monobloc pumps do not differ significantly at present. Just a few years ago, the former were less effective. Today, however, "technology has moved forward", so it is enough to choose a device of a proven brand, and thus - quality, with power adapted to the energy demand of the building. It doesn't matter if it's split or monoblock.

So the question is: which solution to choose - split or monoblock? There is no one good answer to it. In short:

• the principle of operation of both types of devices is the same, they can also be equally effective when it comes to energy production,
• split pumps are cheaper, but their assembly is more demanding, plus additional costs may arise (regular leak checks + product card),
• monobloc pumps are more expensive, but can run quieter and are less likely to suffer from leakage problems. However, they must be additionally protected so that they are not damaged as a result of freezing of the wires.