First things first, if you are thinking about building an A/C unit cold room, it’s time to do some planning.
There are many reasons to build a cold room for your home, farm or office. Think about the future when you sit down to plan it out. Many people find that after a certain time they need more space, or they did not need so much. Next, think about budget. If you are not prepared to do the job right the first time, it may be best to consider professional help in this project. Building a cool house is a meticulous process that when complete will last years and decades with little maintenance.
The two biggest issues to deal with are sealing and R-Value. With proper sealing and a good amount of R-value insulating, your project can be a money saving investment for your needs. Doing a poor job, or going cheap on insulation will be more costly in the future, so allow your budget the most bang for your buck. How you build the room is largely dependent on your climate. Where you live, how much sunlight, and what weather you expect your room to endure are key elements to your planning.
Consider this, it’s not always how thick the insulation is that counts, it is also the quality. For instance it is a complete waste of time to ever consider building a cold room with blown fibreglass or cellulous. These materials are simply not designed to withstand riggers of a well-built room. Wall, roof and floor, all need special consideration. Some 4 inch walls will be fine, but sometimes you will need to consider a 6 inch wall. For many applications the floor is not as important. The best process of flooring is a layer of foam or stiff insulation, under the final layer of plywood that is painted with deck paint.
Again, sealing is key to doing it right, and the outside is just as important as the inside. Tape, caulking and foam insulation are generally the best, each being used at specific areas. The R-value goal should be at or above R-30 on all your application. You will have to determine the thickness or material desired. Some choose a Styrofoam insulation, or blown in professional foam insulation works nicely.
Be sure to choose an A/C unit that matches the space you are designing and be sure that it has the needed “breathing” room. By planning well, and out of direct sun, your room can be safe, inexpensive, wise investment.