Which Type Of Gas Fire Should I Purchase

[man100]

I am looking to replace my present gas fire with one that will be more efficient with gas usage whilst at the same time giving good heat.
The fire I have at the moment is a Brilliant Innovation open living flame inset model using a precast flue in a room approx. 17ft x 11ft x 8ft
I have visited several retail outlets in my area and unfortunately get different advice it seems mainly regarding keeping with an open type or one with glass in front of the flames.
Another point is it better to have a larger output fire ie 4.5kwh and then turn it down as the room warms up or have a 3kwh one from the point of view keeping fuel costs down.

[toolbox]

With a precast flue your options may be limited, check the fire is suitable. In general live effect DGF (decorative gas fires) are the least efficient almost the same as a coal fire about 25%. Old style gas fires that sit against the wall like grannie had were more like 70%. The more "real" they look as a rule of thumb the less efficient. Check the technical specifications of the fires you like, they will have a guide to % efficiency, or look at the input gas rate compared to the output rate.