PHOENIX — The International Code Council has finalized its International Green Construction Code and is readying it for publication by Spring of 2012. The code includes many water and energy saving features that will be familiar with anyone who has followed other green codes, standards and programs. It also has provisions intended to make the code simple to follow without performing calculations.
For example, Section 607.5 on pipe insulation for HVAC systems also carries over to pipe insulation for plumbing. Other codes and standards, such as ASHRAE’s Standard 90.1, contain more complicated instructions on pipe insulation, but the IgCC keeps it simple — insulation thickness is equal to the pipe diameter, up to 2-in., explained Gary Klein, Affiliated International Management LLC, who submitted numerous code change proposals at the hearing. Thus, ½-in. pipe gets ½-in. insulation, 1-in. pipe gets 1-in. insulation, and so on up to 2-in. Larger pipe, 4-in. for example, would also get 2-in. of insulation. If large pipe is in a commercial building, the engineer can specify thicker insulation if he so desires. The vast majority of pipe installed in the U.S., however, is 2-in. or less. Steam pipe insulation would be twice as thick.
ICC works on prescriptive green construction code
Another simplification involves how much pipe can be used for hot water systems. Long waits for hot water are the bane of conservation experts who joke about starting the shower and then making a pot of coffee while waiting for hot water to arrive. To reduce this waste of water and energy, most green codes, including the IgCC, require either an on-demand hot water recirculation loop or heat tracing on the pipe.
Previous attempts to limit the amount of wasted water mandated how many ounces of water could be in the pipe between the source of hot water (such as the recirculating loop) and the fitting. The problem with calculating ounces, however, was that each type of pipe — copper, PEX, PE or CPVC — has a different interior volume.
The IgCC dumps that approach, states that all pipes will be considered to be the same, and states how many feet of pipe can be used, Klein said.
Table 702.8 says, for example that for 1/2-in. pipe, you can run 43 of pipe on systems that do not have a recirculating loop or heat tracing. For systems that do have a recirculating loop or heat tracing line, the maximum length of ½-in. pipe from the loop to the fitting is 16-ft. For public lavatory faucets the maximum distance is 2-ft. People washing their hands on public washrooms give up quickly, so if you truly want to deliver hot water to the fixture, especially with a low-flow faucet, you better get the hot water there quickly. Table 702.8 gives the maximum number of feet allowed for 11 sizes of pipe from ¼-in. to 2-in. Some of the diameters aren’t common, but they are included in the table nonetheless.
Klein got everything he asked for on the topic of recirculating hot water systems. If the answer to long waits for hot water is a recirculating loop, a pump that runs constantly will waste more energy than it saves. The IgCC prohibits continuous, timer, or water temperature-initiated operation of a circulating pump. Gravity or thermosyphon circulation loops are prohibited.
Recirculating hot water systems must be controlled with either hard-wired or wireless controls activated by: 1. A normally open, momentary contact switch. 2. Motion sensors that make momentary contact when motion is sensed. After the signal is sent, the sensor must lock out for at least five minutes to prevent restarting the pump while the circulation loop is still hot. 3. A flow switch. 4. A door switch.
The controls have to keep the pump off if the temperature is above 105°F in case the device that senses temperature rise fails. Controls must also have a lock out that prevents extended operation of the pump if the sensor fails or is damaged.
Plumbing fixture flow rates were simplified to single numbers on a table presented by engineer H.W. (Bill) Hoffman, H.W. (Bill) Hoffman & Associates LLC. The IgCC originally had two numbers built around a base case and a better case. California’s CalGreen code has three possible flow rates.
“We did this in consultation with the major fixture manufacturers,” Klein said. “We asked them, ‘can you live with the WaterSense numbers,’ and they said yes. One number for each fixture or fitting is better than three or four like CalGreen has because the manufacturers would need all different stuff. And from a code point of view, why encourage three different flow rates? Just do one and eventually the country would adopt it.”
Showerheads would be limited to 2.0-GPM, private lavatory and bar sinks faucets to 1.5-GPM, kitchen faucets to 2.2-GPM, urinals to 0.5-GPF or non-water, and toilets to 1.28-GPF. The table also has flow rates for public lavatory faucets, pre-rinse spray valves, and drinking fountains.
Thomas Pape, Best Management Partners, representing the Alliance for Water Efficiency, got one alteration on the table for remote water closets that may be on the end of a drain line in a commercial building. Those can be 1.6-GPF water closets if they are, “… located not less than 30-ft. upstream of other drain line connections or fixtures and … located where less than 1.5 drainage fixture units are upstream of the drain line connection.”