Feature Article

Texas Residential Supavent Installation

 

This feature article details the technical aspects and results of installing 4 Supavent wind turbines in a residential application and the dramatic effects on temperature profiles within the attic space and overall energy reduction for the client.

The client's story and a half residence is located in Sugar Land, Texas on the southwest side of Houston - an area well known for moderate to low winds and hot climate during summer months. The residence is slightly under 3800 sqft living area, with an attic space that employed the traditional favorite - ridge vents and soffits - as primary ventilation.

The client was plagued by high air conditioning costs, typical of many area homes. Looking for a way to reduce monthly summer a/c electric bills, the client opted to install 4 Supavents in an attempt to improve attic ventilation and reduce overall energy consumption.

The Supavents were installed in June 2009 in addition to the ridge vent system and soffits left intact. Total attic volume was calculated in the order of 20,000 cuft, with a complex roofline but the attic was connected throughout. The Supavents were installed on the back side of the residence, and are not visible from the main drive or front of house. The Supavents were selected primarily for superior "wind only" ventilation capabilities. Design flow rate for the Supavent is about 170 CFM at 7.5 mph windspeed. Weight of unit is 4.2 lbs (2 kg).

RESULTS

Attic Temperature Reduced 30% & Overall Household (A/C) Power Consumption Lower by 8.5%

The chart to the left summarizes the before and after data snapshot of the attic temperature & differential profile for the residence. The differential temperature is defined as attic temperature minus ambient temperature. The data was collected over the period utilzing calibrated memory temperature data recorders located in the attic, living area, and outside ambient. Consistent data was collected for 3 days prior to installation and 3 days after installation under similar ambient conditions. As evidenced by data, the temperature cycles within the attic clearly demonstrated that the ridge vent system resulted in an attic temperature profile that was consistently 30 degrees higher than ambient temperature before Supavents were installed. This differential was reduced to only 20 degF with Supavents were a moderate breeze was prevailing. The period of time for the attic temperature to recover to ambient after sunset was improved by about 1 hour and warm up was delayed by about 1 hour in the morning. Household total power consumption during the test under the ridge vent system consistently showed about 100 KWH per each 24 hr period compared with 91 KWH/day with ecoPower, about a 8.5% reduction.

 

The key findings after installing the Supavents are:

• 30% drop in attic differential temperature.

• 8.5% savings in cooling costs with Supavents.
• Increased comfort level in second floor living area.