Tag Archives: health

Disturbing study

Out of all systems we touched during our deep energy retrofit, the domestic hot water plumbing revealed the most unexpected surprises and opportunities – and as it now turns out, potential risk.

An article published in Environmental Science: Water Research & Technology by William J. Rhoads, Amy Prudena and Marc A. Edwardsa states:

“This study raises concerns with respect to current green water system practices and the importance of considering potential public health impacts in the design of sustainable water systems.”

(Environ. Sci.: Water Res. Technol., 2016,2, 164-173)

The researchers point to increased residence time of water in plumbing systems that have been built with water conservation (i.e. low flow fixtures) and efficiency in mind to get their green building credits. To quote hot water guru Gary Klein:

“…the rules for sizing the piping do not have a way to account for these lower flow rates and fill volumes. On top of that, standard engineering practice is to add a safety factor on top of the calculated design. The result of this tension between the plumbing code, engineering practice and water use efficiency has the effect of dramatically increasing retention time in the piping.”

That increased retention – or – residence time comes with risks:

“Concentration of 16S rRNA and opportunistic pathogen genus level genetic markers were 1–4 orders of magnitude higher in green versus conventional buildings.”

(Environ. Sci.: Water Res. Technol., 2016,2, 164-173)

A write up of the study was published in Chemistry World.

pipe-sizes

Let’s unpack this by taking a step back:

Thanks to Gary Klein, we have an efficiently structured plumbing system that maximizes energy, water and material conservation.

Well – maximizes with a lowercase “m” because the Chicago Plumbing Code got in the way. ½” is the smallest fixture branch (or twigs) size that is allowed (Chapter 18-29-604.5 Size of fixture supply). Yet the combination of our structured plumbing system and low flow fixtures validates 3/8″ fixture branches (twigs) and fixture supply lines, which would help keep excessive residence time at bay. This is a matter of right sizing the piping for fixture branches (twigs) and fixture supply lines to match the flow rate of the fixture they serve. Gary Klein puts it this way:

“lower flow = smaller water volume to deliver = smaller pipe sizing”

The 3/8″ fixture branches (twigs) may be unimaginable in Chicago, but other places have caught on to the smaller pipe sizing principle, as I found out when visiting my friend Oliver in Sweden.

plumbing-042

I have come across a lot of bitching and moaning about the Chicago Building Code and inspections. Yet I learned to appreciate the code and the inspection through the process of our deep energy retrofit. Even if some things seem cumbersome and over the top, it is with our safety and welfare in mind. And the plumbing code is unambiguous about it:

“18-29-101.3 Intent: The purpose of this chapter is to provide minimum standards to safeguard life or limb, health, property and public welfare by regulating and controlling the design, construction, installation, quality of materials, location, operation, and maintenance or use of plumbing equipment and systems.”

Chicago, I am glad you watch my back! Except that sometimes you don’t. Sometimes the world is moving faster than you are. And everything having to do with green building is picking up speed every year. That includes encouraging developments in water conservation and low flow fixtures. I am sure ½” fixture supply pipes once were a rock solid safety standard – before the emergence of low flow fixtures. But these days… As Gary Klein points out:

“Reducing flow rates without reducing pipe volume is a recipe for disaster, as the study points out.”

Will I swap out all of our low flow fixtures with regular ones? Nope, not yet. And Gary gave me a little peace of mind:

“You actually were able to reduce the volume [and residence time] by the way you did the [structured] plumbing.”

Dear Chicago: I would appreciate it if you would live up to your health and safety intent. Take note of the study “Survey of green building water systems reveals elevated water age and water quality concerns” and adjust the plumbing code to allow smaller pipe sizes. Stay abreast of the green building developments, and in the process keep us safe – keep watching our backs!

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Summer heat or summer freeze?

With the summer heat and humidity upon us, it is nice to escape every now and then the mugginess and soaring temperatures. Escape into a slightly cooler space, except that those spaces are impossible to find.

I think this is a recurring summer topic. Last year, I wrote that instead of cooling off some, we are sent into a deep freeze. I dread stepping into and out of any grocery store, which usually has been turned into one giant freezer. Going to the movie theater requires extra warm clothing in order to avoid hypothermia. The first thing we do when stepping into a restaurant or bar is scoping out the location of the air vents in order to find a seat that is outside the reach of the freezing draft.

I wrote about the industry standard for air conditioning including the recommended temperature ranges, and contemplated the need for a more adaptive approach. An approach that sets indoor temperatures somewhat proportional to outdoor temperatures, making the transition from the outdoors to the indoors much more pleasant, and less like a temperature shock.

The constant transition from the outdoor 90’s into the conditioned mid to lower 70’s cannot be good for our physiology. Or is it? Well, that’s what Google is for.

I searched for negative health effects associated with air conditioning or excessive air conditioning, and found … nothing!

All I found were references to excessive heat and associated health risks; or the spread of bacteria and mold spores through AC systems or reported cases where Legionnaire’s disease has been spread from cooling towers. But nothing really on the effect on our physiology.

I tried something else: I Googled the same subject in German. Et Voila, (pardon my French) I stumbled on a couple of references to sources that discussed the issue of temperature differentials between air conditioned spaces and the outdoors, and associated health issues.

One recommendation that showed up a couple of times, was to restrict the differential to 10 degree Fahrenheit. Admittedly, this has to be set into the context of central Europe, which doesn’t all that often match our Midwestern summer temperatures.

The German web references also mention that the transition across a broad temperature differential makes our circulatory system work extra hard. On reference compares it to a sauna experience, except that in the case of the sauna the cooling down time is relatively short, followed by a resting time in a normal temperature environment. Plus the cycles from hot to cold during a sauna experience are typically limited to two or four times.

Running a number of errands during a hot summer day can in fact exert more stress on our physiology and circulatory system than a typical sauna visit.

Now, why is it that this is not discussed in the English language? Or is it just me, doing a lousy job on Google? Have you come across serious articles and publications that address this topic? If so, I really would like to know about it! Please leave a comment.

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DWV Part 3 – visions

We have more exciting plans for the future, beyond a greywater system. At one point we would like to convert the former pantry into a small half bathroom. It would have a tiny corner sink and – drum roll – a composting toilet!

Sadly, that would get us onto a serious collision course with the Chicago Plumbing Code and probably the Department of Health too. Our objective is to find a solution that is code compliant today, but allow for a simple ‘plug and play’ switch once the codes are brought up to date.

What if…

… composting toilets will not be allowed anytime soon? That is a real probability because of the prejudice that exists around this technology.

Furthermore, composting toilets require regular maintenance, which worries the regulatory agencies. In other words, if a composting toilet is not maintained, it may become a health hazard.

The tertiary stack

Another DWV stack – a tertiary stack – should help us to solve this problem.

I described the primary stack (blackwater stack) and the secondary stack (greywater stack). The tertiary stack is also a blackwater stack located at the back of the basement with connection to the underground sewer.

This tertiary stack would initially serve a regular low-flow toilet in the half-bath room. Once the code is updated we can remove the regular low flow toilet, retire the connection to the tertiary stack, and install the composting toilet.

The composting toilet does not require a connection to the DWV plumbing or the sewer. It is a standalone system that has a collection chamber where the human waste is composted and turned into organic matter.

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DWV Part 1 – rationales

Let’s go back in time for the next posts. I would like to dissect the plumbing system some more. A good starting point is the drain-waste-vent (DWV) plumbing.

I described the PVC to CISP connection and the DWV basement installation. But I said little about the rationales and layout other than the discussion about the new CISP sewers and the check valve location.

The moment we look at what goes down the DWV plumbing, sustainability creeps into the picture. As the name suggests (drain-waste-vent) we are talking about draining waste water. Although, not all waste water is equal.

Blackwater…

… is the term coined for the waste water we flush down the toilets – water that contains fecal matter and urine. Blackwater requires processing, typically in a waste water treatment plant, where pathogens and organic matter are removed. Only then and once disinfected is it safe (from a human health and safety aspect) to release into the environment.

There are a number of other, ecologically sound, smaller and/or decentralized blackwater treatment options such as constructed wetlands and the ecological engine, which have been widely researched and published.

Greywater…

… is the watered down cousin of blackwater. By definition it cannot contain human waste.

Greywater typically originates from the sinks, showers, bathtubs and washing machines of our homes. Because it carries lower levels of contaminants, it has a lower health risk.

As such, greywater can be recycled and reused. Typical applications for recycled greywater are landscape irrigation and indoor reuse such as toilet flushing. Outdoor use, and more so indoor use, may require some level of filtration.

Policy potential

We know about, and often practice, recycling – extracting another use out of a resource rather than letting it go to waste (pun intended).

Greywater is a resource that has recycling potential, given the right plumbing layout. Rather than having one DWV system that drains everything, it can be structured to separate blackwater from the recyclable greywater.

There is one minor problem, though. Our plumbing code in the city of Chicago does not allow the reuse or recycling of greywater, point blank. The Uniform Plumbing Code prohibits the use of greywater indoors.

I don’t think it takes a visionary to figure out that, given increased pressure on our natural resources, the current policy must expire sometime in the future.

Anticipating the policy change, we would like to avoid opening up walls to get to and modify our DWV system. Instead we would like to proactively structure our stacks and sewers for easy adaptation of greywater collection once it is permissible.

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Soil gas, radon and health

I am moving down on my basement floor to-do list. The next task, the installation of the soil gas pipes, is all about health.

We spend the majority of our days indoors, yet we are not paying much if any attention to the health of those indoor environments. The indoor air quality (IAQ) of many work and living places is pretty lousy.

The green building movement is trying to change this by raising awareness of the IAQ issue. Poor IAQ can lead to low productivity at the workplace and health issues at work and at home. And we all know is that medical bills can be pretty expensive.

After having done some research on the radon issue, and after having decided that we will turn the basement into a garden unit, we realized that the installation of a soil gas pipe system for radon removal is an incredibly cheap IAQ insurance.

How does it work? I have four strands of 2 inch perforated, rigid plastic pipe traversing the basement. The strands are connected to a 4 inch perforated collector pipe.

soil-gas-pipe-01

The rigid plastic pipes collect any radon from the center portion of the basement. The perimeter drain, a flexible, perforated pipe, can collect any soil gas along the basement edge. If I connect it to the rigid plastic pipes it would perform double duty, keep the foundation wall dry (which also improves IAQ), and assisting with radon removal.

soil-gas-pipe-02

I like the idea of double duty and so I connected the 4 inch perforated collector pipe to the perimeter drain. The collector pipe lines up with one of our chimney flues, through which we can vent the soil gas removal system.

soil-gas-pipe-03

I prepared the chimney base, extended the collection pipe and left a stub to which we can connect the vent stack that will extend to the roof.

soil-gas-pipe-04

If I terminate the vent stack a few feet above the roof line with a material that readily heats up in the sun, I can rely on the negative pressure of the stack effect to draw soil gas out of the system from under the basement slab. I let thermodynamics do the work for me. I love it.

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