Energy-Efficient Guidelines for New Construction
SITE, SELECTION AND ORIENTATION
Site selection and orientation of buildings offers the biggest impact for energy efficiency. Building with a keen attention to design details yields a more efficient building with greater value. Once the site has been dug into and the foundation established, most of the future energy savings and expenses can be projected, and the savings incurred count immediately against any added building cost. It is important to make all energy decisions before the concrete is poured because it is difficult to alter the building’s future energy usage afterwards.
Passive Solar Building Plan
The primary way to save energy is by adhering to a passive solar building plan. This plan incorporates every known way to save future energy dollars and adds comfort and value to the home and the site. The first crucial step in this plan is a well-designed structure that takes advantage of excellent site placement.
Passive solar design creates a building that uses sunlight wisely (passively). The homeowner or building tenants benefit from this wise use of the sun because their monthly energy bills are lower for the life of the building, and the comfort within makes the building more valuable.
An efficient shape and orientation of the structure is crucial to maximizing comfort for both hot summer days and cold winter winds, and careful placement of windows and doors can lead to daily savings in the future. An efficient shape means that the long axis of the building will run East-West. C–shaped buildings are not efficient and are therefore not recommended.
The East and West sides of the structure need shade trees where possible, and until the trees mature, awnings can be placed on the building as a stopgap. There are some exceptions, of course. Some buildings, such as adjoined townhouses may not have East/West windows, and in some small sites where there is no room for trees, awnings will have to take their place.
Additional Savings with Passive Energy Features
- No attic! Move the central air conditioning out of the attic and into the conditioned space. Dedicate 100 square feet of inside space to the utilities that are usually put up in the attic. The cost of using this interior space is immediately offset by the significantly lower costs for heating and air conditioning. All ductwork will be in the conditioned space instead of where it is usually placed, in the area of the vaulted ceiling. If an attic must be used, it is vital to ventilate and insulate it very well, and to use a radiant barrier as an excellent shield from heat.
- Insulation. A tight, well-insulated shell costs more initially but has important, long-lasting, cost-saving advantages.
- Cool-Roof products. Light color roofing material is one step better than black roofing, but, unfortunately, standard roofing materials absorb the infrared (hot) wavelengths of sunlight. There are now cool-roof products that do not absorb heat, and do not get hotter than the outside temperature.
The size of the system is extremely important. Too big and it runs for too short a time and causes discomfort and humidity problems (mold). Two fan speeds to handle variable conditions are recommended. A very slow, almost continuous fan speed adds comfort and removes humidity, and it costs much less to operate. Then there is the new blower-door technology to detect leaks in the ducts. Today we use mastic to clamp and seal ducts instead of duct tape, and this upfront construction cost will pay for itself very quickly.
Programmable thermostats instead of manual thermostats automatically help control energy usage, and therefore reduce costs.
CEILING FANS IN EVERY ROOM
Ceiling fans reduce the need for around-the-clock air conditioning. A house can be wired with a switch near the main doors so that all ceiling fans can easily be turned on and off at the same time.
Windows and doors should be of highest quality for maximum energy efficiency. Their placement in the structure is even more important. Most apertures must be placed on the North and South face of a building here in Texas. The East and West exposures receive months of hot sunlight that is best minimized, especially during the long hot days of summer when the Western sun penetrates our buildings and results in high electric bills. All that is needed to reduce the additional energy costs that poor placement creates is proper attention to the orientation and design of the site that includes well-placed shade to help keep heat off the building. Where possible, this is best achieved with the awnings and trees.
GROUND SOURCE (Geothermal)
There is an endless source of 60 degree coolant in the ground under every building, and it is relatively easy to bring this 60-degree ground source out of the ground and into the structure. Similar to a water well but two-way, the heating and air-conditioning (HVAC) system is fed the 60 degrees and it removes the byproduct, heat. The Enthalpy Wheel Heat Exchanger—a necessary component for ground-source heating and cooling that looks like a revolving tray—takes this 60 degrees out of the ground well into the HVAC by way of its heat exchanger and removes the old hotter or colder air. A regular forced-air system then delivers the correct air temperature to the building.
25 percent of the energy bill for a household is for producing hot water.
There are two ways to reduce this:
- Solar Water Heater. In Dallas we need to watch our water usage carefully, so the only drawback to making hot water on the roof is that we waste water while we are waiting for the hot water to get from the roof to the sink. Also, due to freezing temperatures in winter, we must use an Indirect Solar System with a heat transfer fluid and a heat exchanger. A 4’ x 10’collector is needed on the roof for this, along with a highly insulated storage tank (Marathon or equivalent), which reduces standby losses.
- Instant Hot Water On Demand. Greatly improved, and in use around the world, the Instant Hot-Water System stores no water and is very energy efficient. These mini hot-water systems are located where hot water is needed, which eliminates the tank, the heat of the tank, and the energy needed to heat the water in the tank.
Energy usage is skyrocketing as homes are outfitted with bigger and bigger appliances. Consider appliances with the Energy Star stamp of approval, and get rid of old, energy-guzzling appliances (as for example, an old refrigerator that gets stored as an extra cooler in the garage). For greater energy savings, consider Sun Frost or similar manufacturers of marine and RV equipment who make energy-efficient refrigerators and other appliances.
Insulate Those Pipes! Better yet, put all plumbing fixtures together in a compact footprint. To keep the costs of construction down, design the kitchen and bathrooms back to back. Never put plumbing on an outside wall where it may freeze, and always put freeze guards on outside faucets.
Consider perimeter insulation for slab foundations, but be advised that it can be a pathway for termites. If yours is a termite area, consider installing mesh screen and ought three (.03” diameter) sand to act as physical barriers to termites.
INTERIOR LOAD MANAGEMENT
List the energy ratings on all appliances and add them up to learn exactly how much energy they use. Install switches to cut off certain appliances (stereos, TVs) and eliminate the constant power drain. One switch by the front door or the garage door can shut off all the ceiling fans when they’re not needed. All those extra transformers for cordless telephones and electronics stay warm because they are using electricity. Consider how many there are and plan for a switch that can turn off the ones you do not need when you leave the house.
Compact fluorescents (CFs). Very necessary for energy conservation because they produce substantial light and remain quite cool to the touch while burning very little energy. Be sure to check out the correct products when attempting to use a fluorescent light under a ceiling fan with a dimmer switch because the wrong ones make a terrible flicker.
A heat exchanger makes clean, conditioned, warm air out of cold outside air and makes cool air out of warm air, thereby reducing energy usage. Heat exchangers also work very well for heating pools, as do thermal solar panels.
Back in the days before AC, our Texas homes had big porches and awnings, but when air conditioning came in, we gave up the porch and its shady refuge. In any passive solar home built, the prominent overhang on the South side of the building is a very necessary component to shade the home’s main windows. And, more crucially, the overhang must not block out the sun when it begins to get low in the South during late fall. An eyebrow overhang of the right size allows the winter sun to fully penetrate the building.
LOW E WINDOWS
The windows on the South side may not need to be the top-of-the-line low e (coated) windows because the sunshine in winter can be used to warm the house. Used on the East and West, low e windows block the harsh Texas sun.
THERMAL MASS INSIDE
Thermal mass inside refers to designing an area which will hold and help maintain constant indoor air temperature. The new thinking is to have the layer of bricks that are normally put on the outside of a building moved to the inside. A big brick wall, chimney, or concrete pillar inside would hold the heat in winter, or the cool air in summer, releasing it slowly to keep the inside temperature from fluctuating rapidly.
The idea is to get the intense heat from stovetops and ovens out of the house. With the bar-b-que taking center stage today and helping this to happen, it’s a good idea to plan a little outside area that can be expanded to include shade and protection from the elements.
HOW THE AMERICAN HOUSE GREW TO BE HOT
- We put in hot-water heaters ovens, stoves, and other appliances with motors and hot exhaust. We use burning hot light bulbs liberally.
- We put our air conditioning units in hot attics and run fat tubes through intolerable heat to air condition our living space. We do the same in reverse for heating in winter when all those ducts carry precious warm air through the freezing cold attic. And all those ducts are loosely sealed and leak conditioned air.
- Our bigger windows are manufactured inexpensively and are more affordable, but they cost more in the long run as they let in heat and damaging sunlight.
- Our walls are too thinly insulated, especially around front doors and attached garage walls.
Americans spend nearly $1,000,000 per minute for energy. If we all were to conserve energy, just imagine how much money would be left in our pockets at the end of every month.
The first cost of switching to energy-efficient methods has been a major barrier in the past. Buyers need sustained incentives to reach the goal of energy efficiency, such as knowing that any energy savings they have made will ultimately pay for improvements in homebuilding and encourage new products.
Government plays a role in determining the minimum standards that must be met by building codes. If we raise these standards to reflect more energy efficiency, we will all be helping to bring down our usage of energy. We won’t need to build more power plants, and the new generation of homes will be compatible with renewable energy technologies well into the future.
Fossil fuels gave us cheap, reliable energy for a century. Moving forward, today we can choose to develop a new generation of Zero Energy Homes right here in the world home of the oil and gas industry.