Educating yourself about energy efficiency in the home begins with understanding energy demand.
In this post we look at the energy demand you place on your home. From there, it’s much easier to work with an Arlington, TX air conditioning contractor to determine a whole-house systems energy efficiency strategy, which includes service schedules, repairs, equipment replacement, and energy efficiency upgrades.
The information presented is meant to give homeowners a better understanding of a whole-house approach to energy efficiency when working with an Arlington, TX air conditioning contractor to implement change.
What is Energy Demand?
Energy demand is the amount of energy needed to achieve certain functions like maintaining a comfortable temperature your home.
When homeowners talk about conserving energy they are really talking about reducing energy demand. Reducing demand can be done in a number of ways, many of which are simple behavioral changes.
For example, to reduce lighting demand, one can let natural light in to the home by opening window coverings. To reduce hot water demand, set the water heater to 120 degrees, take shorter showers, run the dishwasher only when full, and wash clothes using cold water. Unplugging appliances when they’re not in use will reduce “phantom” electricity demand.
For heating and cooling, energy demand depends on how we choose to counteract the extreme temperatures that make us uncomfortable in the hot and humid Arlington summers and the mild to bitter-cold winters.
- In the cold months, warm air in the home is lost to the cold outdoors through the ceiling, walls, windows, foundation, and through air leaks in the “building envelope.”
- That lost warm air needs to be regained through some combination of internal heat (body heat of people in the home, the use of heat-producing lights), heat from the sun, or heat generated from a furnace or boiler.
- In warm weather, hot air enters the home as direct radiation from the sun through leaks in the building envelope as internal heat (again, from people in the home, the use of computers, TVs, and other heat-generating appliances), and through the building envelope as warm air naturally invades colder indoor spaces.
- It’s simple physics at play here: Excess warm air in our homes needs to be removed until we are comfortable.
The whole-house approach to energy efficiency that many Arlington, TX air conditioning contractors recommend dictates that instead of utilizing just large heating and cooling systems, it is more cost-effective to decrease the forces that make us uncomfortable in the first place.
- Reducing air leakage by air-sealing the home — something that you can do yourself or, if you prefer, you can use an Arlington, TX air conditioning contractor or specialty company to seal the home.
- Slowing the transmission of heat with insulation and energy efficient windows. Again, you can add insulation to the home yourself or hire an Arlington, TX air conditioning contractor (or specialty windows company) to do the installation.
- Making solar heat work to your advantage by smartly improving windows (from installing solar shields to replacing old windows with energy-efficient ones). This also includes wisely using window coverings and by smartly landscaping your home for energy conservation. Some of these improvements you can do yourself, while others you will want to use an Arlington, TX air conditioning contractor or specialty company.
- In addition to the above, sealing and insulating ducts prevents hot and/or cold air generated by heating and cooling systems from being wasted on their way into living spaces.
- Proactively utilizing a thermostat can also reduce your heating and cooling demand.
(We will discuss many of these in more detail in upcoming posts.)
By minimizing energy demand through some of the “passive” techniques listed above, one can then minimize the need for “active” energy systems like expensive-to-run-and-operate air conditioners, furnaces, and hot water heaters.
Money is saved not just through the reduction in energy demand, but also through the purchase of smaller or less-expensive equipment. There is no reason to overpay for energy you are no longer using or simply wasting through inefficiencies.
Conventional vs. Tightly-sealed vs. Well-insulated
After reducing energy demand the next step of a whole-house approach to energy efficiency is purchasing energy-efficient equipment.
As noted, some equipment could be smaller or even unnecessary after energy demand is reduced. Although up front cost of more energy efficient equipment is higher than standard equipment, financial incentives at time of purchase and long-term reductions in energy use can offset much of these additional costs.
To understand heating expenses for conventional, low-demand, and efficient homes, consider these figures. (These are for illustration purposes only and may not accurately represent what you experience in your Arlington home.)
Installed furnace cost
Conventional home: $1,500 (Average of R-18 insulation, 60,000 BTU and 80 percent efficient furnace)
Tightly-sealed, well-insulated home: $1,200 (Average of R-24 insulation, 40,000 BTU and 80 percent furnace)
Tightly-sealed, well-insulated home with efficient furnace: $2,200 (Average of R-24 insulation, 40,000 BTU and 95 percent efficiency furnace)
Insulation and air-sealing cost
Conventional home: $0
Tightly-sealed, well-insulated home: $1,000
Tightly-sealed, well-insulated home with efficient furnace: $1,000
Conventional home: $1,500
Tightly-sealed, well-insulated home: $2,200
Tightly-sealed, well-insulated home with efficient furnace: $3,200
Conventional home: $0
Tightly-sealed, well-insulated home: $700
Tightly-sealed, well-insulated home with efficient furnace: $1,700
Therms per year
Conventional home: $1,400
Tightly-sealed, well-insulated home: $640
Tightly-sealed, well-insulated home with efficient furnace: $540
Annual operating cost
Conventional home: $680
Tightly-sealed, well-insulated home: $380
Tightly-sealed, well-insulated home with efficient furnace: $320
Conventional home: $-
Tightly-sealed, well-insulated home: $300
Tightly-sealed, well-insulated home with efficient furnace: $360
Payback period (years)
Conventional home: $-
Tightly-sealed, well-insulated home: $2.3
Tightly-sealed, well-insulated home with efficient furnace: $4.7
Lifetime operating cost
Conventional home: $13,600
Tightly-sealed, well-insulated home: $7,600
Tightly-sealed, well-insulated home with efficient furnace: $6,400
Conventional home: $-
Tightly-sealed, well-insulated home: $6,000
Tightly-sealed, well-insulated home with efficient furnace: $7,200
In comparing the conventional home vs. the tightly-sealed, well-insulated home, the initial investment in an effective building shell (of improved insulation and air sealing) is somewhat offset by the need for a less expensive to purchase and operate furnace.
The purchase of high efficiency in a tightly-sealed, well-insulated home with the efficient furnace significantly increases upfront costs.
That said, both investments in improving the building shell and buying efficient equipment saves the homeowner a significant amount of money over the lifetime of service, repair, and upgrades expected in the conventional home.
Financial incentives like utility rebates would make the upfront investments less expensive and rising energy prices (which is usually a good bet in Arlington) would make the payback periods even shorter. Working with an Arlington, TX air conditioning contractor will help you understand the costs and tradeoffs.
Another benefit of the whole-house approach is that investments in energy efficiency can decrease the costs of renewable energy and, perhaps, the need for ongoing service and repairs.
It is important to understand the whole-house approach to energy efficiency in order to make sound long-term energy investments and understand your equipment and service, repair, and maintenance needs going forward. Working with an Arlington, TX air conditioning contractor will help you understand the issues and tradeoffs.
Once you understand where energy is being used in your home, you can focus on reducing energy demand through energy conservation measures and a passive, less expensive, approach.