How to design a Split system

How to design a system with Split System

Plant air conditioning with independent air conditioners

Explanatory guide indicating how to design a split system

How to design a system with Split System

The design of a split-type air conditioning system is a crucial process for guaranteeing thermal comfort in residential and commercial environments. This guide was created to be your complete guide, a reliable companion through the process of designing such systems.

Understanding how to correctly design and size an autonomous air conditioning system is essential to ensure the well-being of people in buildings, as well as to optimize energy efficiency and system life. The guide will walk you through every step of the process, from analyzing your cooling or heating needs to selecting equipment, designing connections, and installing considerations.

But we will go beyond the basics. We will also explore the principles of operation of these systems, the benefits and challenges of using these devices, and how to meet the specific needs of different applications.

We'll also discuss the latest trends in the HVAC industry, such as the use of advanced technologies and sustainable solutions to improve efficiency and reduce environmental impact.

We hope this guide will become your trusted resource for designing this type of system. Whether you are expert technicians, designers or simple enthusiasts looking for detailed information, you will find here the knowledge and skills needed to design air conditioning systems that meet your needs.

Let's start this journey together, discovering how to design air conditioning systems that improve the comfort and energy efficiency of buildings.

How to proceed

First let's take a look at the environments to be conditioned:

let's open the program

Summer heat load - split system and fan coil units and fill in all the required fields:

It is necessary to have as reference the thermal loads necessary to supply the system (in this case, obviously, there is no need for a refrigeration unit) to obtain what we have foreseen.

The total result is 26.1 kW.

But let's analyze the necessary potential environment by environment by reading them directly last line

So let's assign the standard potentials to the split considering the same ones to the inverter and the nominal cooling power:

Secretariat 2.7 kW
Anteroom 2.7 kW - 3.5 kW
Meeting room 18.3 kW - 7 kW x 3 - 5 kW x 4 - 3.5 kW x 5 - 2.7 kW x 7
No stress area 2.7 kW

In the anteroom we will consider n. 1 2.7 kW split and in the meeting room we will consider n. 7 split 2.7 kW (just to unify the supply).

We deliberately did not consider multisplits and VRV systems.

In the hope that some notion of Cad drawing you have (but also in pencil is fine), we move on with the placement of the split (related to the environmental loads) in the individual rooms.

You can also download free Cad blocks for air conditioning from this link:

Conditioning blocks

Let's consider split for floor installation of 2.7 kW thermal and place them together with the outdoor units:

In the meeting room, as previously discussed, other potentials could also be adopted (example 7 kW x 3 - 5 kW x 4 - 3.5 kW x 5).

We power the split electrically assuming that they are Class A ++ and that absorb 0.9 kW (nominal power). We round up to 1 kW:

We also create the condensate line which in this case will end in the toilet, by means of a siphon that guarantees the non-propagation of any annoying odors.

Let's also take a look at the exhaust air expulsion system carried out via an in-line extractor of 200 mc / h and we heat the bathroom and anteroom with 1 kW electric fan coils.

Finally we calculate the section of the power supply cable of the general panel (10 kW) and of the individual disconnections (5 kW x 2) using the program:

Sizing of electrical cables - calculator

As you can see, with a few steps and having everything under control, you can calculate everything that is necessary for the construction of the system using the program Estimative metric computation being careful to find the “n. price list ”right. Not all of those shown in the example match.