Closing the door is the best option for a uninsulated basement that becomes as cold as the air and ground outdoors. With the door open, the house's main-level thermostat will sense the drop in temperature as the cool air from the basement circulates throughout the house.
Better Comfort Throughout Your Home
Even if you don't spend a lot of time in the basement, keeping it warm will make a difference in other parts of the house — particularly the rooms right above it. We talked about the same phenomenon when we looked at bonus rooms above garages.
We know that cold air is heavier than warm air. Cold air will work its way down until it finds the lowest level of the home or a room that it can not go any further. This leaves the warm air to move up and occupy the upper levels.
One rule of thumb to help determine the basement temperature is to average out your area's temperature across the entire year. In the summer, the basement is often cooler than the outside air. In the winter, the basement is often warmer than the outside air.
It can be tempting to slam the doors and hope the cool air builds up in the areas where you want it, but the fact is that modern air conditioning units are designed as whole-house systems. So when you shut that door, you're only making it much harder for your system to cool your home.
Heat moves from warm rooms to cool rooms, especially in a two-storey home where upstairs is cooler. Keeping doors closed reduces this significantly in rooms where thermostatic radiator valves are used well.
Buy a space heater for the basement
This is probably the most popular short-term solution for a cold basement. And it makes sense. Space heaters are relatively cheap and easy to use, and they can make a big difference in the comfort of your basement—quickly.
Typically, an unheated basement will stay between 50 and 55 degrees, assuming there are no gaps to the outside. Most frozen pipes happen when they are inside the exterior walls above the basement, not in the basement.
Try using rugs and even roughed-in insulation to warm the space to at least 55 F. In the summer your basement will probably stay cooler than the rest of the house, but keeping it at 80 F or lower will help suppress humidity and mildew. Ideal Basement Temp: 55 F to 60 F in winter; less than 80 F in summer.
This is a result of hot air rising and cold air falling. As the basement is below ground, it is the best-insulated floor in your house. So, if your basement is always cold, it's because the cold air is being trapped.
Warmth & Comfort
Further, hard flooring can also make your basement difficult to heat. Padding and luxurious carpet make for warmer temperatures in the cellar, which ultimately help to keep the upstairs portion of the house warm, too and can even lower your heating bill.
These rooms are typically used to store wine, potatoes, flower bulbs, and other items that need a cold, damp space to thrive. This is not only a good space to house these items, but it is much cheaper than running a fridge!
The room likely won't even feel warmer with a dehumidifier. That's because the dehumidifier is removing excess moisture, so you'll feel more comfortable than without the dehumidifier. More importantly, you'll be in a healthier environment that won't suffer from structural damage, mold and other long-term issues.
Many unfinished basements have cold, concrete slab floors. At minimum, laying throw rugs over trafficked areas will keep feet warm and help to insulate the floor from the cold. For additional insulation, consider installing wall-to-wall carpet or engineered flooring.
Proper basement insulation can significantly reduce heat transfer. In turn, this keeps the central part of the home comfortable without running the heat more often. The house becomes more energy-efficient, and homeowners pay less in energy costs.
Prevent heat loss with spray foam insulation
When you use spray foam insulation on the walls of your basement, and to seal the gaps in the area above the sill and along the rim joists, it can reduce heat loss by as much as 30% to 40%, saving money on heating bills.
Space heaters are the most affordable option for heating your basement, but they're ideal for smaller spaces. Some people are also wary of space heaters, particularly if small children are in the house.
For saving big on energy costs and maximizing your comfort, the ductless heat pump should be your go-to heating system in the basement. Ductless heat pump is an energy-efficient unit. It delivers conditioned air straight to the focused area, eliminating heat loss.
Contrary to common belief, closing off a room can actually make your heating less efficient. When interior doors are kept shut, the pressure in the room increases because the flow of air is now blocked. The air in the pressurized room will not stay in the room; it will find ways to get out.
Why Leave Doors Open? Although it's a common belief, shutting doors to rooms you are not using will not save you money on heating or cooling costs. It will only force your HVAC system to work overtime, causing potential long-term damage.
When the furnace is operating, it pushes conditioned air into each bedroom. If the bedroom doors are closed, there's no easy way for the air to get back to the return-air grille in the hallway.