With any sealed or sound-proofed room, the challenge is in getting a constant flow of fresh air into the room and getting the stale air out. Taking with it any excess moisture, especially from a room situated underground. If adequate ventilation isn't achieved, a muggy, damp, and hot climate will be the result - far from ideal living conditions!
The downside to adding ventilation is that it creates a path for sound to travel through, minimizing the amount of sound reduction between the room and outside. This can be mitigated with the use of an acoustic maze providing an insulated, winding path for the air to travel while making it difficult for sound waves to maintain their energy. An example of one of these is below...
These boxes tend to be pretty big and take up a lot of space that, unfortunately, my basement is not blessed with. However, as I mentioned in my initial planning stage, complete sound-proofing was not my top priority so I decided to live without this particular acoustic solution. The ducting run I planned was set behind sound-proof plasterboard and surrounded with acoustic treatment while making several tight turns to slightly replicate some of the benefits of an acoustic baffle. Perhaps not as effective, but still providing a reasonable reduction in unwanted sound transmission while saving on space.
I decided not to just have a straight in/out ventilation system, rather install a heat exchanger to warm up the incoming fresh air in the winter, and take out any excess moisture from the basement. I went for the Vent Axia HR100R which could be installed between the joists of the basement 'corridor'. In addition, I needed to install a condensate pump to extract the excess water removed by the heat exchanger to above ground level.
The next task was connecting up all the ducting. With the intake air supply coming from the back of the house through to the back of the studio, and the exhaust taking stale air from the front of the studio to the front of the house - all via the heat exchanger. This made for some long duct runs which, fortunately, would positively impact sound reduction. One challenge was getting the ducting underneath an entire room to the outside, using the DIY method of taping several long sticks together, taping the sticks to the ducting, then trying to wriggle that through the vent to the other side of the basement.
Although I needed to start this process early, I couldn't finish until the walls, electrics, and ceiling had reached a certain stage. So I had to work around dangling ventilation for a few weeks...
I could then attach the internal vent grilles...
Sealing in all aspects of the ducting system needed to wait until nearer the finishing stage, so we'll see more of the finished project in later blog posts.
Next time, we'll be looking at starting on the electrics of the studio.
Frank Leonard Walker