ᐅ Air Conditioner: Daikin or Mitsubishi?

Good evening everyone, we are planning to move our bedroom and home office to the attic next year as we are expecting a child. Since it gets very hot under the roof in summer, we have considered installing an air conditioning system.

Room 1, which will be our bedroom, is about 28 square meters (300 square feet), and Room 2, a small office, is about 10 square meters (110 square feet).

So far, two contractors have visited, and we have received three quotes.

Contractor 1 – Daikin:

1x Split wall unit R-32, Stylish, white (CTXA15) – 1.5 kW for the office
1x Split wall unit R-32, Stylish, white (FTXA25) – 2.5 kW for the bedroom
1x Daikin inverter multi-split outdoor unit – cooling capacity 4 kW for the outdoor unit.

Price including installation approximately €8,800 gross

Contractor 2 also offered Daikin:

1x Split wall unit R-32, Stylish, white (FTXA20) – 2 kW for the office
1x Split wall unit R-32, Stylish, white (FTXA25) – 2.5 kW for the bedroom
1x Daikin inverter multi-split outdoor unit – cooling capacity 5 kW for the outdoor unit.

Price including installation approximately €9,050 gross

Our budget is €8,500 gross. Contractor 2 has now proposed to modify the offer as follows:

1x Split wall unit R-32, Stylish, white (FTXA20) – 2 kW for the office
1x Split wall unit R-32, Stylish, white (FTXA25) – 2.5 kW for the bedroom
1x Daikin inverter multi-split outdoor unit – cooling capacity 4 kW for the outdoor unit.

However, he points out the following: In this case, I would keep the indoor units at 25 + 20, but if both run at the same time, they would not deliver full output. This is usually not an issue since typically only one room is cooled at once.

With a discount, the price would be €8,510 gross.

To our understanding, the power should be sufficient for both rooms, and they can run simultaneously, just not at full power, right? Theoretically, 1.5 kW for the office plus 2.5 kW for the bedroom with a 4 kW outdoor unit should be enough?

Alternatively, he also offered Mitsubishi for €8,510 gross:

1x MXZ-2F53VF4 – outdoor unit – cooling capacity 5.3 kW
2x MSZ-AY25VGKP – 2.5 kW each for the office and bedroom.

Everything including installation for €8,343 gross.

How would you decide? Thank you in advance for all your answers.

If you cool evenly, you only need a low continuous power output. The maximum power would only be required if you want to cool down from 30°C (86°F) indoor and outdoor temperature to 18°C (64°F) at full capacity.
If you aim for normal cool (not cold) temperatures of around 23-25°C (73-77°F), that works well.

It will probably even be sufficient for just one unit to run once the mentioned temperature is reached.

Okay, so this setup should be appropriate:

1x split wall unit R-32, Stylish, white (FTXA 20) – 2 kW for the home office
1x split wall unit R-32, Stylish, white (FTXA25) – 2.5 kW for the bedroom
1x Daikin inverter multi-split outdoor unit – cooling capacity 4 kW for the outdoor unit.

This should fit and be sufficient in terms of capacity if it runs continuously on warm days.

We have one FTXM20R with 2 kW in both the bedroom and the guest/multifunction room, and a more stylish, silver-colored Stylish unit with 5 kW, model FTXA 50AW, in the large open space with a gallery. The outdoor unit is a Multisplit 3MXM68N with 6.8 kW. We paid just over 10,000 in 2021, as far as I remember, although this of course depends on factors like line length, locations, etc.

Whether 1.5 kW units would have been sufficient, I can’t say for sure, but I think they probably would be.

philipp1990 schrieb:

Okay, so this setup should be appropriate:
1x wall-mounted split unit R-32, Stylish, white (FTXA 20) – 2 kW for the study
1x wall-mounted split unit R-32, Stylish, white (FTXA25) – 2.5 kW for the bedroom
1x Daikin inverter multi-split outdoor unit – cooling capacity 4 kW for the outdoor unit.
This should fit and be capable in terms of performance if you run it continuously on warm days.

I think that setup works. Air conditioning was a great decision—never without it again; sometimes we even use it briefly for heating. I had also looked into Mitsubishi, but I didn’t like it. The Daikin app control works very well.

We have similar performance in the living area and bedroom; the units are modulating and only run at about 2 kW electric power right after starting.
After half an hour, they reduce to around 1 kW, and after 2 hours to 0.6 kW.
The temperature is set to 23°C (73°F) as the target temperature.
Photovoltaics work well for this, easily powering the air conditioning.

I have several Daikin units. They all operate with a demand control set at 50% or 70%, meaning the output is permanently limited so that when they turn on, they don’t run at full power for 30 minutes. This means full capacity is never actually needed.