Enviro Water Saver

Special note:

Enviro Save Water System is designed to save and store for reuse (within the sealed water circuit) any water which has cooled in the hot water lines that would otherwise flow out of the hot tap and down the drain prior to the hot water arriving at the spout or shower. For this to happen, cold water in the hot line needs to be detected and redirected into the cold line when connected. Therefore, the cold line needs to be at a lower pressure than the hot line.

To reduce the cold line pressure a Pressure Reducing Valve (PRV) must be installed in the cold line, downstream of the hot water T-off point. The patented Thermal Switching Valve detects cold water and redirects it to the storage tank. Saved water is returned from the tank whenever a cold outlet (including toilet) is used, and before any new cold water is drawn into the system from the mains supply. The ideal differential between cold and hot line pressures is 150 Kpa.

Installation:

Locate the mains-in supply to the heater unit, check and note pressure. If the pressure exceeds 500 Kpa consider fitting a PRV upstream of the heater T-off point and set it at 450 Kpa as this will save more water. Fit a PRV in the cold line downstream of the heater T-off point and set it at 300 Kpa (or 150 Kpa less than the pressure in the hot water line). Ideally, the hot water is now at 450 Kpa and the cold water is at 300 Kpa, a difference of 150 Kpa.

Fit the pressure (storage) tank in the cold line anywhere downstream of the cold line PRV. Set the tank air pressure at 302 Kpa (or 2 Kpa more than the cold water pressure). Set the tank air pressure with nil pressure at the water inlet (i.e. no water in tank). Do not situate the pressure tank in sunlight.

Fit a Thermal Switching Valve in the hot line under the sink or basin, connect the cold-out port into the cold water line. Now cold water, when detected in the hot line, will flow into the cold line then into the pressure tank.

The Thermal Switching Valve has an inlet strainer and the cold outlet a non-return valve. Valve TSV 2A suits two-taps-and-centre-spout tapware and single lever mixer tapware or single hot tap, or a remote hot line. See valve fitting instructions diagram.

Note:

The minimum differential is 70 Kpa. Cold water pressure can range from 140 Kpa to 450 Kpa, and hot from 210 Kpa to 600 Kpa. The greater the difference and the lower the pressure maximises the water quantity which can be saved in the tank.

Check tank size table for capacities.

Refer to trouble shooting section if necessary.

Test:

Turn on the hot tap. There may be a dribble or no flow of water until hot water arrives. ONLY hot water will flow from the hot tap. If no water is available the valve will bypas cold water until the pressure tank is full. If necessary, to empty the tank and restart the system, turn on a cold tap until a hot tap flows hot water.

Note: The saved water can be piped to a rainwater tank. In this case the Pressure Reducing Valve and the Pressure Tank are not required.

This system complies with Australian Standards 5200-475, 485 and 481.

Support Information for Enviro Save Water System

Function

Turn on a hot water tap and Enviro Thermal Switching Valve TSV2A when fitted in a hot water line will detect cold water and bypass it to save via a side outlet. When hot water arrives the valve switches and delivers hot water to the tap and the bypass closes. The hot tap dribbles as an alarm that the hot tap is on and the cold water in the hot line is bypassing to save for later reuse.

Location

The valve can be installed under a sink or basin, in a ceiling or under a house, just before a tee off to two wet areas sharing a common wall, it is best located as close to the hot outlet as possible. Fit a valve under a basin before the tee off to the bath and shower and all hot taps downstream of the valve will operate the valve.

Save water options one.

The valve save water outlet is at tap pressure, the water can be piped anywhere, up or down, to a rain water tank, any suitable tank, any downpipe to a tank, even a Bunnings $89 x 100 litre tank with a tap for pots or garden use.

Save water option two

Connect the valve save outlet into the cold line, equal pressure wont flow so fit a Pressure Reducing Valve (PRV) and set at 150 kpa lower than the hot line pressure , now water will flow if it has somewhere to go, fit a pressure tank in the cold line set air pressure at PVR pressure setting.

Higher hot water pressure will flow into the tank, via the cold line, when hot water arrives at the valve it switches and hot water flows from the tap. The bypass closes.

When any cold tap is used including toilet flush the pressure tank empties before new water enters the system, it all happens automatically

Hardware items

All hardware is supplied direct from Enviro Manufacturing Co, usually 2 days delivery for tanks

Express post if required for valves.

Any Plumber can fit the hardware it is a simple basic plumbing operation. Full instruction supplied.

All the hardware is fully approved and is covered by Aust Standards ATS 5200-475-481-485 and should be installed as per Plumbing Code 3500.

Cost

The valve is $198,--PRV.$98.--  Tanks, 20 lt $179.-- 35 lt $299, -- 60lt  $429.

Installation cost, Valves only.

New dwelling, Cost of hardware, hardly any extra labour, maybe some extra pipe and a few fittings 

Retro fit, to existing dwelling

Location, accessibility and plumbers can vary pricing, however most valves can be installed in 30 minutes, plus the save water pipe run which depends on distance and accessibility. A plastic pipe like Yorkflex or simular is around $3 per meter.

To install the full system in a new dwelling is simply part of the fit out, plus the extra hardware.

To retro fit a full system depends on house type, houses off the ground are simple, houses on a slab depend on pipe access, however 3 hours is a general estimate to complete a fit out. Good access 2 hours.

Some facts

Instantaneous Gas heaters can flow 1,7 to 2.5 litres of water before constant hot water flows at the heater, at the hot tap the volume can be up to 3 time, the at heater figure. WELS survey.

Solar heaters need to be located to suit the sun exposure; this is not always the optimum location to save the cold water from a hot tap. Fit an Enviro valve at remote hot taps 

If you have a say, locate the heater close to the kitchen sink, this is the frequently used hot tap, group other wet areas if possible. Aust Standards use 19 hot tap operations daily as a test guide.

The less hot pipe used the less water wasted.

Smart piping location can save water, cluster wet areas close to heater, maybe kitchen and bathroom, if one location like an Ensuite is remote fit a Enviro valve.

Remember laundries use a lot of water but don’t usually waste water. If you need a bucket of hot water to mop the floor catch the cold and dump it in the washing machine,. Laundries don’t usually need a valve.

Caution, this information is general and may not apply to all locations, conditions and applications.