A cold bedroom feels like a heating problem, so people go looking for more heat. Half the time the room is not short on heat at all. It is leaking the heat it already gets, and adding 1500 watts to a leaky room is paying to warm the outdoors.

Find the leaks before you spend anything

On a windy evening, walk the room with the back of a wet hand near window frames, sashes, baseboards, and the door. Cold streams announce themselves instantly. Do this before you compare heaters at https://reaks.us.com/, because the diagnosis decides whether you need one.

The usual suspects, in order

Old double-hung windows leak at the meeting rail and where the sash slides. Doors leak at the bottom, then the latch side. Wall outlets on exterior walls breathe cold. Attic hatches and window air conditioners left in place over winter are enormous, ignored holes.

Cheap fixes that a renter can undo

• Rope caulk pressed into window gaps, peeled off in spring.
• Shrink film over the whole window, sealed with a hair dryer.
• A door sweep or a fabric draft blocker at the threshold.
• Foam gaskets behind outlet and switch plates on outside walls.
• Lined curtains closed at dusk and opened for winter sun.

Why film beats almost everything

A single-pane window loses heat by conduction and by air movement against the cold glass. Film adds a trapped air layer and stops the convection loop that drags warm room air down the glass and across your floor. It costs a few dollars per window.

Check the heat you are already paying for

Vents blocked by a dresser, a closed damper, a filter that has not been changed since spring, or a radiator valve turned down by a previous tenant all starve a room. Bleeding a radiator or moving furniture is free and often ends the problem outright.

What sealing will not fix

An uninsulated exterior wall, a room over an unheated garage, or a heating system that never reaches the far end of the building are structural problems. Weatherization narrows the gap, but it will not close it, and that is when supplemental heat earns its place.

Run the experiment for one week

Seal everything, then track how the room feels at bedtime and at dawn. Many people discover the room is now merely cool rather than cold, and a warm bed handles the rest. That result saves the purchase, the electricity, and the fire risk.

If you still need heat, buy less of it

A sealed room needs a smaller unit, a lower setpoint, and shorter runtime. The same heater that struggled in a drafty room will cycle off on its thermostat in a tight one, which is the difference between a modest bill and an alarming one.