Tap is 90 psi

[scottish cleaning service]

Just tested my tap pressure and it came out at 90psi. Just wondering what is the best membrane HF4 or 5 ? many thanks

 

[spruce]

This came from Alex's website when he still sold membranes;

HF4 Axeon membrane.

• Commercial AXEON HF4 Low-Pressure 4040 40" Membrane
• Optimum input pressure range 80-105psi (5.3-7 BAR)
• Average Rejection ratio - 98% (200ppm down to 4ppm with input water at 100psi and 25°C input water temperature)
• Recommended waste water ratios (product:waste) - 1:1 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
• Suitable for standard water input temperatures +10°C
• Nominal 2,500gpd rating - Real world will produce from 2000-4500 litres per 24 hour day

HF5 Axeon membrane

· Commercial AXEON HF5 Ultra Low-Pressure 4040 40" Membrane
· Optimum Input Water Pressure range is 50-100PSI (3.4-7 BAR)
· Suitable for low water temperature inputs below 10°C & generally lower pressure than the HF4 RO Membranes
· Average Rejection ratio - 97% (200ppm down to 6ppm with input water at 100psi and 25°C input water temperature)
· Recommended waste water ratios (product:waste) - 1:1.5 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
· Nominal 3,000gpd rating - Real world will produce from 2000-5000 litres per 24 hour day

 

[scottish cleaning service]

This came from Alex's website when he still sold membranes;

HF4 Axeon membrane.

• Commercial AXEON HF4 Low-Pressure 4040 40" Membrane
• Optimum input pressure range 80-105psi (5.3-7 BAR)
• Average Rejection ratio - 98% (200ppm down to 4ppm with input water at 100psi and 25°C input water temperature)
• Recommended waste water ratios (product:waste) - 1:1 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
• Suitable for standard water input temperatures +10°C
• Nominal 2,500gpd rating - Real world will produce from 2000-4500 litres per 24 hour day

HF5 Axeon membrane

· Commercial AXEON HF5 Ultra Low-Pressure 4040 40" Membrane
· Optimum Input Water Pressure range is 50-100PSI (3.4-7 BAR)
· Suitable for low water temperature inputs below 10°C & generally lower pressure than the HF4 RO Membranes
· Average Rejection ratio - 97% (200ppm down to 6ppm with input water at 100psi and 25°C input water temperature)
· Recommended waste water ratios (product:waste) - 1:1.5 under 100ppm, 1:2 100-250ppm, 1:3 250-400ppm
· Nominal 3,000gpd rating - Real world will produce from 2000-5000 litres per 24 hour day

I'm right in the middle so I could run with anyone like my TDS, I seem to be the fulcrum.

 

[spruce]

I'm not making a decision for you, but I would go the HF4 route, provided that is your regular water pressure. I didn't make a note of it, but I seem to remember Alex also saying a minimum flow through the tap of 9lpm, but they could have been if a booster pump was included in the system. Mine was 13lpm, so I never that gave much notice to what he had specifically written.
Not only is the HF4 membrane a little more efficient, it's also a bit cheaper. It does, however, produce water at a slightly slower rate, which I very much doubt you will notice.

 

[scottish cleaning service]

I'm not making a decision for you, but I would go the HF4 route, provided that is your regular water pressure. I didn't make a note of it, but I seem to remember Alex also saying a minimum flow through the tap of 9lpm, but they could have been if a booster pump was included in the system. Mine was 13lpm, so I never that gave much notice to what he had specifically written.
Not only is the HF4 membrane a little more efficient, it's also a bit cheaper. It does, however, produce water at a slightly slower rate, which I very much doubt you will notice.

Not sure what HF I bought but my flow rate is good. Amazing how we go and buy membranes without even thinking about our pressure. I have just winged it and bought wrong stuff until it eventually all fits together. Beginning to toss stuff out and having big clear out when my clear plastic boxes arrive today. ?