Oil filled heaters can help reduce the overall heating costs in most households if they are implemented properly. One important fact to remember is that just replacing heat usually provided by a central heating system with a number of electric room heaters will most likely not result in a reduction of your heating costs. Of course this will depend on a number of factors such as the relative cost of electricity and heating oil or natural gas in your area. Where portable electric heaters and oil filled heaters can save money is when they are implemented in a way that targets the heat only where it is needed as opposed to heating the entire volume of the house as is the case with a central heating system.
The best space heaters for heating a room such as a bedroom or living room are oil filled heaters, provided you desire to heat the space for several hours at a time. The advantages of oil filled heaters are several:

• Because oil filled heaters are convection heaters that rely on the natural movement of air created by temperature differences between the heater surface and the ambient temperature, they do not rely on a fan. Many people find fan heaters objectionable because of the noise and the tendency to dry the air.
• Oiled filled space heaters are considered safer by many because of the modest temperatures of the heater surfaces. The actual heating element is housed within the metal housing and merely heats the oil which in turn heats up the surface of the unit.
• Because of the large surface area, once the heater is brought up to the correct temperature, the heat produced tends to be steady and not as prone to temperature swings that one might experience with a small fan heater for example.

Of course there are a few downsides to an oil filled heater. Because they do not employ a fan, they require a larger surface area to transfer the heat from the heater into the room. If you are short on space you might consider a panel heater that may be wall mounted or possibly a ceramic or quartz fan heater. Also if you desire a quick blast of heat for a short period of time, then a fan heater would be a better choice. For example if you would like to have a source of heat in the bathroom while showering and dressing in the morning, and do not want to leave it on all day. use a fan heater.

Since the maximum rating for a portable electric heater is restricted to 1500 watts of power, all models of portable oil filled heaters rated for 1500 watts will produce the same heat. What you are paying for in the pricier models are such features as remotes, timers and more advanced thermostats. There are a few lower powered models and one advantage is that they are physically smaller.

Oil filled heaters are the best space heaters to use where heat is needed in a small to medium sized room over an extended period of time. For short blast of heat or for heating a small area within a larger space, other types of portable electric heaters are better suited.