It’s crucial to get the right size of air conditioner for the room it’s going to be servicing. Let’s look first at why this is.
If you over-specify your system and get one that is too large, you are setting yourself up for a number of problems. You’ll be wasting energy, because the system will be cycling on and off constantly. You can also run into problems with humidity, because a large system doesn’t need to run for very long before it achieves the temperature it has been set at. It then switches itself off, but this may be before it has finished taking the humidity out of the air. So you aren’t achieving the air quality you were hoping for.
Alternatively, if the system is too small for the space, it will struggle in extreme temperatures and will constantly be on as it tries to achieve its pre-set temperature. This means that it is using a lot of energy.
When you look at air conditioners, you’ll see that they are listed with a number and BTU. This stands for British Thermal Units. It’s a measure of how much heat (or cooling capacity) a machine can produce. By calculating the area of the room that you want to air-condition, you can select a machine with the appropriate BTU output for the size of the room.
Measure the length and width of the room and multiply the two together to get the square footage. This will give you a very rough guide to the BTUs per hour you need.
Why Professional Estimates Are Needed
The method described above is all very well for air-conditioning a room in a house. But in an office or a restaurant, it won’t give accurate results. A heating, ventilation and air conditioning engineer will be able to get a far more accurate idea of the amount of heat being produced, where it is, and how many BTUs an hour you are going to need from the air conditioning unit given the environment it’s operating in.
Some of the factors that can influence the calculation are the number of people using the room, the equipment in the room, the type of lighting it has, whether it has windows, how many it has and what direction they face, the ceiling height and any insulation above it, the surrounding rooms and so on. And that is for a fairly simple room.
Once you start to add the work processes taking place in offices, shops, factories, restaurants and schools, you can see that the calculations are not simple. In fact, professional air conditioning firms such as Ambient HVAC use complex calculations and their experience to make sure that the unit being obtained and fitted is right for the location.
Without professional advice, it’s possible to make an expensive mistake that leads to your having to replace a unit with a bigger or smaller one because the original equipment wasn’t right for the task. Add to this the fact that there are now many different kinds of air conditioning solution, with different applications and uses, and it’s clear that the sensible thing is to get some technical advice before you buy.