With regards to
Series X compared with
Series 4. We did make a video about the difference
here. The Series X in my opinion is a better model but it's a bit more expensive so it probably comes down to what you can afford. Looking at the numbers for every Series 4 that we sell we move about x9 of the Series X models. So definitely the Series X is significantly more popular, and I would suspect that a lot of the customers purchasing the Series X are upgrading the older Series 4. For this reason, you can probably more easily find secondhand Series 4 units out in the marketplace.
With respect to reliability, we have less than half of the warranty issues with the Series X compared with the Series 4 also. I do not know why this is but both models are relatively reliable, so I am not sure if this is a major factor.
It’s fair to say that both Series 4 and Series X do have some noise and the level of noise is the same. The reason for the noise is:
1. Compressor and refrigerant system.
As you would know we use the hydrocarbon refrigerant gas R600a and this is more noisy than the older and less electrically efficient r134a. In addition to this all these kegerators use an exposed chiller plate. Exposed chiller plates are more electrically efficient but more noisy. So when the r600a refrigerant gas flows into the chiller plate you can get some sound that comes directly off the chill plate. Many domestic fridge designs have the chill plate hidden within the walls of the fridge or behind plastic shroud and this dampens this noise but as mentioned above this type of design uses more power. Also when you rely on an air cavity hidden behind a shroud you gradually get ice build up in this cavity (because our fridges are rated to -5C which is colder than standard refrigerators). This ice build up can eventually block this cavity and forces you to have a defrost heater and timer and this then costs more money, is most stuff to go wrong and obviously heating the fridge once every 6-12 hours will definitely use more energy too.
2. Air Circulation Fan
The majority of the noise is created by the fan. We use a fairly high powered fan in the Series X and Series 4. If you want the fan to be silent one modification you can do is purchase a silent computer fan and swap it over with the stock fan that comes with these units. It's an easy job to do this but generally we have found these silent fans blow less air so the speed at which you chill kegs down will be less. Also if you use a silent fan it also reduces the air blown up the font as well, resulting in your font/tower not as cold either. If you really want quiet then this is probably the best modification to do but just release the trade off.