| Solar fans have simplified attic ventilation. Having been | | | | stand-up attic. The solution is the same. |
| in the business of ventilating attics for almost thirty | | | | The living area with cathedral ceiling will be AT LEAST |
| years, one of the most difficult (and, in fact, | | | | 10 DegF cooler with proper insulation, soffit vents |
| impossible) situations to deal with in completed | | | | and a solar roof fan, without the A/C turned on. |
| construction is heat buildup in completed rooms or | | | | Please note: insulation contractors should ensure |
| finished attics with "up to the peak" cathedral ceilings. | | | | unobstructed airflow from soffit vents to attic. |
| If you're an architect, builder or homeowner | | | | Solar powered attic ventilation is one of the most |
| considering cathedral ceilings, I have | | | | cost-effective ways to improve energy efficiency |
| recommendations you might consider. The present | | | | for air conditioning and to improve LEED score. |
| theory, as reflected in most building codes, is that | | | | Typical installed cost is about $550 after tax credits |
| hot air will travel by convection from the soffit | | | | are applied. Federal Energy Tax Form 5695. Energy |
| vents, through the styrofoam spacers and exit | | | | saving and carbon footprint for cooling can be |
| through the ridge vent. | | | | reduced by 10% to 30%. Payback time is less than 5 |
| Our experience has been that this theory does not | | | | years. Every succeeding year is money in the bank! |
| work very well. In fact, the air below the roof can | | | | Architects would be well advised to include and |
| reach temperatures in excess of 150 DegF. That hot | | | | specify quality solar fans during the design phase of a |
| air is rapidly expanding. Unable to escape through the | | | | project. We have many request from townhouse |
| ridge and soffit vents quickly enough, it pushes | | | | style condo owners because the upper floors of the |
| through the porous insulation, heating up the ceiling | | | | unit are warm, even with the A/C turned on. They |
| and creating a tremendous heat gain to the living | | | | are prevented from taking remedial action because |
| area. Very often, even a well-designed A/C system | | | | they can't get permission from the Condo |
| can't keep up. | | | | Association Committee. |
| SUGGESTION: Design a small attic over the cathedral | | | | A minimum 10% reduction in energy usage (and |
| ceiling. A solar-powered roof fan will exhaust heat | | | | proportional reduction in carbon footprint) for cooling |
| from the "attic", creating a vacuum, thereby pulling in | | | | is a huge number. Moreover, it's most effective at |
| cool air from the soffits through the spacers. This | | | | the exact time when the stress on the "grid" is the |
| creates an envelope of cool air around the living | | | | greatest, during hot weather. Cost saving to the |
| space, (If you already have some flat ceiling, just add | | | | utility company by not having to upgrade their |
| a solar fan). . | | | | infrastructure because of reduced peak demand is |
| These heat gain forces are the same in a regular | | | | substantial. |