Engineering – It’s Not Just a Job, It’s a Lifestyle

Having been in the energy efficiency industry for over a decade, it was always a sore point when SWA’s senior engineer, Srikanth Puttagunta, talked about his own home.  Built in 2003, the townhome was energy inefficient and uncomfortable. With the thermostats set at 70°, temperatures in individual rooms could be 5-10° colder or warmer than the setpoint.

What was the best solution?

Moving. This past year Sri purchased an older split-level home with upgrades to the kitchen and bathrooms. But, it was still energy inefficient. With the help of trusted SWA collaborators Preferred Builders Inc. and Controlled Temperatures Inc., Sri followed the same advice he’d been giving all these years.

Steps to Energy Efficiency

The first step was to insulate and air seal the building shell.  The  old fiberglass batts were removed from the exterior walls (a) prior to dense packing  the wall cavities with cellulose (b), taping all seams in the sheathing (c), installing a drainable housewrap (d), and re-siding (e) with fiber cement siding. After that came air sealing of the roof deck with closed cell spray polyurethane foam (f).

The Perks of Natural Gas

Taking advantage of the availability of natural gas, the old heating system – an oil boiler with an immersion coil for domestic hot water – was replaced with a natural gas, condensing tankless combi-boiler that feeds the existing baseboard radiators and provides domestic hot water.

Keeping it Cool

Cooling was previously provided by a through-wall air conditioner in the kitchen area and window air conditioners in the bedrooms. These were removed and a multi-head mini-split heat pump was installed that provides cooling and supplemental heating. Finally, a 5.2 kW  solar PV system was installed on the roof (g).

The Results

Based on the previous homeowners’ oil and electric bills, energy modeling and testing of the home (73% reduction in air leakage), and initial utility bills since moving in, the upgrades that were performed on this home should result in a nearly 70% reduction in annual energy costs. With about $3,850 per year in savings, the simple payback is less than 15 years. Now that is a home that anyone can be proud of!

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