Hot Water Systems

Introduction

The failure of hot water systems identified during Housing for Health survey/fix projects continues to be high and running cost a major expense.

Only 74% of Indigenous houses tested had a hot water system that delivered water at 45°C or above. (NIHG Ed 3)

Identifying poor environments

Detail2 2

Testing HWS temperature during Housing for Health Survey/ Fix project

128 2843 Img Copy 

Hot Water Elements

Examples of Hot Water System failures:
Electric HWS failure & corroded element from water with high mineral salt content

Designing for better health

Recommendations of how to improve delivery of hot water to householders.

Hws Gr1  Hws Gr2  Hws Gr3

Implementation of a monitoring programme of 3 different types of hot water systems: heat pump, solar and electric.

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The problem

The failure of hot water systems identified during Housing for Health survey/fix projects continues to be high and running cost a major expense.

Only 74% of Indigenous houses tested had a hot water system that delivered water at 45°C or above. (NIHG Ed 3)

Examples of HWS failures:

Hws Gr6 Solarrust2 Copy Hws Gr10 Img 0040Example 1; corroded solar HWS due to high mineral salt content in water. 

Hws Gr7 No Relief Valve Drain To Ground Example 2: There is no relief valve draining to ground which means overflow of hot water could spray out above head height.

Hws Gr9 Leaking Salt Water Decays Roof SheetingExample 3: Leaking salt water from roof mounted solar HWS decays roof sheeting.

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The solution

Implementation of a monitoring programme of 3 different types of hot water systems: heat pump, solar and electric.

The project aimed to identify why the failure rate of hot water systems is so high in regional and remote areas, based on data collected in Housing for Health projects. To compare different hot water systems, side by side with respect to efficiency and performance in different climatic regions and with different water quality issues. Data logging was used to collect information necessary to evaluate the operation of electric, solar and heat pump type hot water systems under the influence of different climate regions, hot/arid, tropical and temperate, and water quality issues from high scaling to high corrosive issues. Analysis of the data will assist manufacturers, architects and builders to choose the most appropriate type of hot water system for the location and use requirements.

Hws Gr1 Hws Gr2 Hws Gr3

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Trial projects

This component of the project built on previous information collected from a tropical location in the Tiwi Islands. 

Data logging equipment was installed in locations in Nyirripi in Central Australia and Nguiu on the Tiwi Islands in order to address the widest range of water quality and climate issues possible. Data loggers were installed on three types of hot water system solar (180-300litre (l)), heat pump (220litre) and electrical (50litre). 

The data systems required scheduled manual downloads onto portable computers. The data was then returned for analysis and assessment with other information.

Hws Gr8 Heatpumptest Image: Trial of heat pump HWS

Outcomes and Recommendations

Data retrieval from Nyirripi was inconclusive on two systems due to incorrect equipment installation. On the third system the logging equipment was removed completely from the hot water system by unknown others.

At Nguiu, data logging equipment was removed from the house with the solar system while it was under refurbishment and never returned, the equipment on the heat pump was removed during repairs and not replaced until it was discovered during a download event. Furthermore the repair on the heat pump was not carried out correctly.

Maintenance data for the hot water units under study was difficult to obtain from the service providers and installation information, incorporated into new house costings, was also difficult to obtain under contractual arrangements between the SIHIP providers and the government.

The combination of new and previous information provide the conclusions:
  • The best value for money for the delivery of hot water to the house remains the solar hot water unit. (note: this is in the absence of ample data from heat pump systems)
  • The best insulated hot water unit is the electric unit
  • The use of manually operated booster switches can provide hot water on demand in solar units while keeping operating costs down.
  • Installation and maintenance standards of hot water systems are still poor as evidenced by this project.

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Where to next?

For information for architects, designers, students, communities, housing managers go to :

Healthabitat website

Housing for Health the Guide

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B1 Washing people

9 Hl Ps 1Poor hygiene increases the transmission of diseases, including diarrhoeal disease, respiratory disease, hepatitis and infections. The rates of these diseases in some Indigenous communities are as high as in many developing countries and are many times higher than for non-Indigenous children.

B2 Washing clothes and bedding

9 Hl Ps 2Regular washing of clothes and bedding, which helps to remove any bacteria, dirt, fleas, mites and other irritants or infection, can help reduce the incidence of infectious diseases, such as diarrhoeal disease, respiratory infections, scabies and other skin infections. 

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Linking health and the house

Linking health and the house

Related Healthy Living Practices

Parts of the house and living environment impacted by this product

Parts of the house that are impacted