Roof ventilation is as important in the winter months as it is in the summer.
In lower temperatures, improper or blocked ventilation cause trapped moisture to freeze in your attic. This frozen moisture will damage the underside of your roof deck, as well as cause interior damage as the ice melts.
If you are afraid that heat may be escaping from your house through your attic vents then your problem is not the ventilation. The problem is that there is heat in the attic in the first place. Excess heat in the attic during cold weather is evidence of a shortage in the insulation used to protect your heated home.
Some weatherization contractors will actually drive through neighborhoods while it is cold and snowing. They can pick out the homes in desperate need of extra attic insulation after a light snow fall. When all the other homes have a thin layer of fresh snow on their roof and yours does not, then you know that you are literally “paying to heat the neighborhood”, as my grandmother used to say.
It may seem that adding attic insulation is an added cost that you can’t afford, but if you put it in perspective it will save you money. Combine the extra heating cost in the winter and the extra air-conditioning in the summer, the amount may surprise you. The money that is leaking through your ceiling every month will justify the investment in attic insulation. It will pay for itself over and over again.