Certification key tool for building smart cities

By: Neeta Sharma

The quality of products and the people installing them plays a significant role in assuring efficiency in the smart cities of the future

Read more: Certification key tool for building smart cities

The silent temperature

By: Enrique Gonzalez

The uniform plumbing code continues to evolve with regard to temperature in water heaters

The Uniform Plumbing Code (UPC) governs the construction, location, and installation of fuel-burning and other types of water heaters.

The UPC defines a water heater, or water heating boiler, as an appliance designed primarily to supply hot water for domestic or commercial purposes and equipped with automatic controls limiting water temperature to a maximum of 210°F (98°C). The water heater thermostat is a device used to set the water temperature within the holding tank, and the UPC does not recommend or mandate a temperature setting for the thermostat, thus making it a ‘silent temperature’ setting. The UPC does, however, contain regulations for minimum requirements that focus on the health, safety, and welfare of the public by mandating specific requirements for the water heater and plumbing fixtures.

The UPC addresses comprehensive installation requirements for water heater safety devices and water heater appliances while referencing the appropriate nationally recognised standards where applicable. There are three water heater safety devices required by the code: the first being a temperature-limiting device designed to prevent the heated water from exceeding 210°F (98°C) by automatically shutting down the energy source and preventing the water heater from becoming a steam-boiler; the second water heater safety device is a vacuum relief valve designed to prevent siphonage within the tank that can result in emptying of the tank (possibly creating steam in the tank), and can even cause the tank to collapse; the third safety device is a pressure relief valve designed to relieve excess pressure, usually at 150psig for residential water heaters. Note that an expansion tank does not take the place of a pressure relief valve device, and that an expansion tank is required when a water system contains a check valve, backflow preventer, or other normally closed device that prevents dissipation of building pressure back into the water main.

A water heater designed for residential or commercial purposes is typically set at 120°F (48°C) from the factory, but what temperature should the water heater be set to when installed? Again, the UPC is silent on the temperature setting for the water heater thermostat and states that water heaters shall be installed in accordance with the manufacturer’s installation instructions. The water heater manufacturers typically recommend a thermostat temperature setting.

Unfortunately, there is no perfect temperature setting as an overlap of temperatures is required for the health, safety, and welfare of the end users. When the water temperature is set too low, the water can create a perfect environment for Legionnaires’ disease. There are documented instances of health hazards associated with water storing vessels set at temperatures known to ‘amplify’ bacteria growth. According to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Guide 12, legionellae have been recovered from cold water, and the temperature range favourable for amplification of bacterial growth is 77°F (25°C) to 108°F (42°C). Furthermore, ASSE indicates that the temperature of the water within a water heater is recommended to be set between 135°F (57°C) to 140°F (60°C) in order to minimise the growth of harmful bacteria found in water. However, these high temperatures put the public at risk for scalding, thermal shock or both. According to the Engineering and Science Division of the United States Product Safety Commission, it takes one minute to receive a first-degree burn at 122°F (50°C), and it takes two seconds to receive a first-degree burn at 140°F (60°C).

Read the full feature in Plumbing Africa February 2016,page 27.

Disabled bathrooms – what you need to know

By: Kelly-Ann Prinsloo – writer

We take a look at the design criteria for disabled bathrooms and how you, the plumber, can overcome the challenges that these bathrooms present

In many countries, including South Africa, certain people are often not considered when architects, contractors and engineers design the buildings in which we live and work. These people are those with special needs – people who are blind, deaf or disabled in some way – and they must be catered for.

Disabled bathrooms what you need to know

SANS 10400 Part S describes a person with disabilities as ‘person who has long-term physical, mental, intellectual or sensory impairments which, in interaction with various barriers, might hinder their full and effective participation in society on an equal basis with others’.

As a plumber, you are in a unique position to provide a basic necessity for people often disregarded and forgotten by the general public. But, before you can provide bathrooms for disabled people – a much-needed skill in the South African plumbing industry – you need to understand what the requirements are for disabled bathrooms.

South African National Standard (SANS) 10400-S: 2011 deals with bathrooms for disabled people. The standard states that: ‘In any building where facilities for persons with disabilities are required in terms of Regulation S1, there shall be one or more toilets or unisex toilet facilities suitable for use by wheelchair users’.

The requirements for a disabled toilet are as follows:

  • In a wheelchair-accessible toilet,

a) The door of the compartment that contains the toilet facilities shall open outwards unless a 1,2m diameter area that is clear of all fittings, fixtures and the line of the door swing is provided. It shall be fitted with a grab rail on the inside and an easy-to-use locking device. The door leaf shall be openable from the outside by the use of a suitable device in the case of an emergency, and such leaf shall be fitted with a suitable means of indicating whether the compartment is occupied;
b) The minimum finished wall-to-wall dimensions of the compartment shall be not less than 1,8m × 1,8m;
c) A distance of not less than 450mm and not more than 500mm shall be provided between the centre line of the toilet and the nearer side wall of such compartment, and suitable grab rails shall be fixed to such side wall and the rear wall;
d) The distance from the front edge of the toilet to the rear wall of such compartment shall be not less than 690mm;
e) The top surface of the seat of the toilet shall be not less than 480mm and not more than 500mm above the floor level;

Read the full feature in Plumbing Africa February 2016,page 23.

Andrew Mboyi – On the cutting ‘Edge

By: Kelly-Ann Prinsloo – writer

Andrew Mboyi has won the Cobra Design competition twice – in 2013 for Edge, and in 2014 for Attraction – and he describes both experiences as ‘amazing’

Read more: Andrew Mboyi – On the cutting ‘Edge

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