San Francisco Energy Efficiency: A Case Study in Saving Money
- September 24, 2015
- Jeff King
- No Comments
In San Francisco, Energy Efficiency Saves Clients Thousands of Dollars a Year
In the Bay Area, a big part of our job is to update century-old residences with modern HVAC, hot water delivery, window systems and insulation. These home performance systems work quietly in the background to keep your home healthy, comfortable, resource efficient and durable for the long term.
We want you to breathe cleaner air and pay lower utility bills after we’re gone. Are we doing a good job? Check out this case study on San Francisco energy efficiency to find out!
Our clients are saving $255 per month on utilities.
When our client’s gas and electric usage dropped by 42%, PG&E called to see if the meter was broken. In fact everything was working just fine: our intelligent building practices were responsible for the dramatic increase in efficient home performance. Three years later the homeowners are still enjoying an average savings of $255 on their monthly utility bills, and we didn’t even install solar panels.
Our intelligent building practices have brought lasting results:
- $165 monthly average savings on electric bill
- $90 monthly average savings on gas bill
- 31% average drop in monthly electric usage
- 44% average drop in monthly gas usage
It’s easy as new windows, insulation and energy efficient products.
Before starting work on this 5,580 square foot William Wurster home, the family’s highest electric bill was $705. Now the average monthly electric bill is $224. We significantly increased the number of lights throughout the home and even added new kitchen appliances, so how did the bill drop so much? The credit goes to five intelligent building practices:
- Energy efficient appliances
- Energy efficient lighting
- New insulation throughout entire home
- Insulated glazings at all windows
- High-efficiency heat & hot water delivery systems
ENERGY EFFICIENT APPLIANCES
The home’s new Energy Star certified appliances include: Bosch dishwasher and Sub-Zero refrigerator, beverage fridge, and freezer drawers.
LONG-LASTING LED LIGHTING
We used high-efficiency LED lighting in every built-in location, including new recessed cans and accent strips throughout the home. Learn more about the sustainable benefits of LED here.
Many early San Francisco homes were built without insulation, meaning cold air comes right in and warm air goes right out. Our fix? Blown-in shredded fiberglass for all unopened existing walls and ceilings, fiberglass batts for all opened exterior walls and ceilings and spray foam for all unventilated roof decks.
DUAL GLAZED WINDOWS
When it comes to heat loss and gain, an antiquated window is as good as a hole in the wall. We installed an updated glazing system that uses two pieces of glass, with a vacuum-sealed space in between, to create a thermal break between the inside and outside. All windows now have modern dual-glazed sashes (or window frames) to make sure the cold air stays out and the warm air stays in.
HIGH EFFICIENCY HEAT
The home’s entire heating system was re-designed for maximum efficiency while providing several modern benefits:
- The home’s heating system is high efficiency gas-fired forced air. There are two furnaces zoned: one for the public spaces in the home and one for the private spaces. For example, the homeowners don’t typically use their bedrooms during daylight hours and don’t use the common rooms during sleeping hours. Dual furnaces allows for more control over which rooms are heated and when.
- Despite exposure and orientation to the exterior, the system is designed to keep all rooms within a comfortable 3 degrees of one another. For example, a room that gets southern exposure should not be significantly different in temperature than one with northern exposure.
- Poorly designed systems often lose a significant amount of the air into the wall cavities due to duct leakage. Our properly designed and installed system has less than 5% duct leakage.
- Modulating gas valves & modulating fans increase the comfort of the heating experience. They do this by allowing for multiple output levels depending on the heating requirements at any given time.
- In order to maximize air quality, the furnaces have high efficiency (high MERV rating) particle filtration systems.
- In the case of this home, we installed hydronic radiant heat selectively to a glass-enclosed sunroom and all bathrooms using a 97% high-efficiency boiler.
Radiant Floor Heat Boiler
HIGH-EFFICIENCY HOT WATER DELIVERY
The domestic hot water system has a 96% efficient tank heater and all primary bathrooms have motion activated water recirculation. What does that mean? Hot water is immediately available at the faucet, reducing the amount of water and heat that is lost in traditional systems. In times of drought, San Francisco energy efficiency and water usage is more important than ever!
High-Efficiency Water Heater
Motion Sensor Activates Hot Water Circulation Upon Entry Into Bathroom
BEFORE: PG&E Records for Electric Usage Prior to Remodel
AFTER: Electric Usage Post Remodel
BEFORE: Gas Usage Prior to Remodel
AFTER: Gas Usage Post Remodel
If you are considering a whole house remodel, it’s well worth investing in high-efficiency home performance systems. Contact us today to learn more about San Francisco energy efficiency through our intelligent building practices.