Looking only at up-front costs, it may seem economical to buy air conditioning or cooling equipment, rather than hire. Assuming that the unit you might buy is comparable to the one that you would hire (unlikely if you a buying from a DIY store), please consider the following ongoing costs. The unit will require periodic maintenance to ensure that it will continue to work effectively. You will have to store the unit whilst it is not in use. Prior to storage it will have to be properly drained and cleaned to avoid possible contamination. Air conditioning units require PAT testing. Add the tax advantage of expense versus capital purchase and it’s easy to see why it’s almost always better to hire a cooling solution than to buy an ongoing liability.