With an exploding world population and shrinking supply of fresh water on the planet, many say (and we agree) that water resources are the next gold standard. In many areas of the country, potable water costs have doubled and tripled in just the last couple of years.10 To survive the coming supply and demand problems, we are going to have to find ways to get the most from every drop.
Plumbing piping systems provide both hot and cold water delivery, so design considerations provide the greatest bene t for indoor water conservation. It is important to remember that water stays in the plumbing lines all of the time. So every time you turn on the hot water, you will be wasting all the water already in the line waiting for that hot water to get to you from the water heater. is means you are paying for and wasting water that you never even use!
Efficient hot water delivery is achieved through a whole-system design approach, not just considering the type of water heater to be installed. Nothing can kill the efficiency of a high-efficiency water heater more quickly than a poorly designed distribution system. For efficient hot water delivery, you must have one of the following:
• Water heating equipment located within 20 feet (30 feet on 2-story homes) of all the wet locations in the house. is could be a tanked or a tankless unit.
• A manifold plumbing system (replaces the main water line with multiple smaller lines run to each fixture) with the manifold (split) centrally located within 10 feet of the water heater and no single branch line length exceeding 15 feet.
• A structured plumbing system (not a manifold system) consists of a main trunk line that services the entire house with smaller branch and twig lines to each wet area and fixtures, with an on-demand water recirculating system installed at the fixture(s) farthest from the water heater, and pump controls located at all wet locations along those long runs in the home.
Another critical element in achieving efficient hot water delivery is pipe insulation. No matter how efficient your design is in delivering hot water to the fixtures, we still see significant temperature drops during transmission or while water is sitting in the lines waiting for the next draw to occur. Also, when the hot water pipes are not insulated adequately, there are substantial heat losses from hot water running through pipes within the conditioned space of the home that add to the cooling load of the air conditioner. Insulation is cheap, easily installed and means hotter water at the tap for you and your family with a lower temperature setting on the water heater. Insulating three-quarter-inch pipe with three-quarter-inch insulation will triple the time before the water cools down; insulating half-inch pipe with half-inch insulation will double the cool-down period.
Plumbing Design
Thursday, October 26, 2017Building Stacked Stories
Foundation, wall and roof assemblies represent large portions of typical construction budgets. Stacked structures with more than one story can save considerably on material resources and therefore cost. Using in-line framing techniques the floor, wall and roof framing members are vertically aligned with one another so that loads are transferred directly downward, providing a sound structural assembly using less framing lumber. Also, since multi-story homes have a smaller footprint than single-story structures, they can be built at higher density, reducing land costs for affordable urban sites.
Building Designing for Two-Foot Modules
If you really want to optimize re- sources, create the least amount of waste and cut your base construction costs, design the building on two-foot increments. Most building materials come in two-foot incremental lengths or widths. Most lumber and millwork come in 8-, 10-, 12- and 16-foot lengths and sheathing, decking and drywall materials in 4 × 8, 4 × 9 or 4 × 10 sheets. Designing for two-foot modules is one aspect of Advanced Framing, which is a more efficient way to frame from both a materials use and energy use perspective (more on this in Chapter 4). So, overall exterior wall dimensions on your plans should be exact two-foot increments, and plate (ceiling) heights should be 8 feet, 9 feet or 10 feet (there is no reason to go over 10 feet) for optimal material efficiency and cost.
The same is true for interior room dimensions, but more with respect to finished flooring materials. Sheet goods (carpet and lino-leum) come in sheet widths of 6 feet, 12 feet or 15 feet, and tile and wood products typically come 25 square feet to a box. If you are not designing to those increments, you are going to waste a lot of materials. e worst case would be to design a room 12 feet and 7 inches wide or 15 feet and 2 inches long. If you are specifying sheet flooring, your installer will need to cut a 7-inch-wide piece to finish o the 12-foot standard roll width. Or for boxed goods, cut 2-inch strips to finish o that 15-foot full square on each run. Since some wood flooring is tongue-and-groove, once the two opposite edges of the piece are used to t the adjoining pieces, the rest of the square is waste as there are no usable edges remaining, or will require additional labor to router onsite.
Your building designer should hand you the finished plan sets, and you should easily see that overall building dimensions (not including exterior cladding) are measured in even 2-foot increments. is means that from corner to corner, sole plates, top plates, stud spacing, etc. all t within the standard measurements that wood framing is manufactured to, so no waste. is is the most efficient use of your money, as there is nothing worse than wasting it on material scraps in the dumpster!
Basic House Design
Typical homes built to current standards do not generally make it more than twenty years without needing some repairs. Many factors contribute to this, but certainly any complexity of the design,
creating potential for water leaks over time, is a significant influence. To reduce this risk, it’s best to keep the basic house design as simple as possible. Starting with the foundation, try to stay as close to a true rectangle as possible, avoiding projections in the footprint. Starting here, everything above the foundation then follows suit, you’ll have a simpler basic structural design, and a simpler roof design will follow. All of these efforts result in lowering the base bids for construction costs.
The shape factor concept used in designing post-tension foundations (SF=Foundation Perimeterº2/Foundation Area)6 indicates that changes in direction or projections require foundation engineering and reinforcements that not only add cost to the foundation, but also increase the incidence of failures. Beyond concerns for the foundation itself, all deviations from a basic rectangular de- sign add complications to structural assemblies and roof designs that are not only costly to build but again have greater potential for leaks. Costs increase not only because of the additional materials required to provide structural support, but also from increased labor that adds time and costs to construction schedules, impacting interim financing and construction costs. And it’s not just the money—chopped-up architectural designs waste natural resources, as they take much more materials to build the same basic square footage.
We also found a study that references shape factor in terms of the relationship between a building’s thermal envelope area and the volume of its conditioned space. From this perspective, buildings with higher shape factors, i.e., a larger area of exposed thermal envelope, use more energy than those of the same area but a smaller shape factor. This was especially true in cold climates due to an increased area of heat loss, and had less to no impact in climates as they progressed along a continuum to warmer.