Lower Heat-Gain & Down Size A/C Equipment
This is great, now that you know where the problem areas are, fix them.
Originally Posted by will_t_greens
If it will help, you could to increase the insulation & save on energy costs.
You don't need a higher CFM furnace, the idea is to downsize the A/C equipment as much as possible.
Listen to beenthere! - Darrell
I second that.
Originally Posted by beenthere
Getting your existing duct system with your existing a/c as tight as possible will net you a tonnage capacity increase with NO need to upsize the equipment, or even change out what you have now. Tightening up your building envelope will meet with the same result.
Many builders fail to grasp how loosely they build a house. Yours is eight years old. Mine is almost fifty. This summer I could keep my house interior comfortably at 75 degrees, and the unit would occasionally cycle, with the outdoor temperature at 105. I had my attic insulation level increased, and spray-on radiant barrier installed. I sealed up ceiling penetrations and other areas of infiltration in the house. My system is 3.5 tons. If I can see this level of performance on a fifty year old house that still has the original single pane windows in place, I'm certain you can take steps to improve the performance of an eight year old house.
Good move with the energy audit...wish more people would get that done and know more about where their energy dollars are going.
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.
I just had an insulation consultant/installer out and he frowned on a radiant barrier in the attic, stating that if I require additional attic cooling (via a radiant barrier) to lower my heat load in the house, then my insulation levels are inadequate. His suggestion was to reduce the heat transfer through the insulation layer. He said there are studies that indicate the benefits of radiant material but other information showing that once heat has contacted the roofing material, most of the heat is changed from radiant to conductive and transferred through moisture in the air and heat build up in the framing. His plan is to add 8 inches of dense-pack cellulose on top of the existing fiberglass blow-in. He suggested that nothing can be done for the finished 500-600 sq. ft. of vaulted ceiling, but some of the heat gain could be countered by adding cellulose for added insulation and reduced infiltration in the remaining 900 sq. ft. of flat ceiling. His plan is also to add 8 inches of cellulose with adhesive on the vertical transition walls that exist between the flat and vaulted spaces as they are "notorious" for heat gain. He also stated that the additional insulation would result in at least a 15% reduction in cooling requirements based on his past experiences. The cost for the added insulation is far less than an upgraded, larger AC system, but the money is only well spent if his claims are true. Any input?
Originally Posted by shophound