Based in the Southwest USA, I am sadly not blessed with a basement, and so temp control is a rather critical and cumbersome task at all times of the year.
All summer long, I used a large freezer unit outside in the garage, with a Baylite pre-wired temp-controller to create a fermentation chamber with a temp range of of 66F to 67.5F. This ensured that fermentation started towards the top of the recommended range for my yeast strains, so yeast got to work quickly and I would typically see bubbles in the airlock within 24 hours.
This winter, I’ll be moving my fermenters indoors, as I don’t have a way of adding heat to the existing unit. I’m apprehensive about not having quite the same level of strict control over the fermenting temp, especially in the first couple of days after the yeast is pitched. Having said this, I did make some great beer back in the UK indoors. My usual strategy is to select a cupboard which is neither too near nor too far from the home’s primary heat source, and far from things which could cause warming or cooling if possible. For example, the kitchen is probably not ideal, as most kitchens heat up considerably when something is in the oven. Close to a window or against an external wall is also not optimal, as much heat will be lost in this area, especially during overnight lows.
I’ve carefully selected a cupboard accordingly. I’m confident that I’ll be able to keep the space in the 60F to 69F range. My plastic fermenters have thermometers on the side, and I have a mini digital thermometer for the space, so I will be able to monitor the difference between the ambient temp in the cupboard and the temp of the beer itself. Temperatures of fermenting beers spike in the first couple of days, as the process creates its own heat. I’ll be keeping an eye on the beer temps and using the old-fashioned cold water bath for the fermenters if I start to see the temp creeping above 73F.