Low e coatings usually applied to the inside layers of insulating glass manage the amount of light and heat either conducted through a window or reflected away from it.
													
																	Double pane low e windows u value. 
									
	
		
	
																	Low e windows have u value and emissivity values that range from 0 02 to 0 20 which means that 80 to 98 of the room s heat is reflected back into the room in the winter. 
																	Energy star provides recommended u factors for your climate. 
																	Double paned windows may have a u factor at or below 0 30. 
																	Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates. 
															
													
									
	
		
	
																	The best high performance double pane windows may have a u factor of 0 30 or lower indicating that they are very energy efficient. 
																	Triple glazed windows may have a u factor as low as 0 15. 
																	Some triple pane windows may have a u factor as low as 0 15. 
																	Are triple pane windows the best. 
															
													
									
	
		
	
																	Gases are heavier than air and therefore provide insulation resistance to air. 
																	The more panes the better right. 
																	For most energy efficient windows the u factor for the entire window assembly is higher than the u factor at the center of the glass. 
																	Triple pane windows work best when enhanced energy performance is a key objective. 
															
													
									
	
		
	
																	Additionally the window selection tool compares average simulated energy costs for your location based on various window types.