Rainman's AC and 48 V units all share one high-pressure pump drawing about 1,250 W. What changes between the 70L, 75L and 140L models is the membrane pack bolted onto the end of it. The pump does not care how many membranes are fitted; it draws its 1,250 W regardless.

So the arithmetic is stark. The 70L uses two 21-inch membranes for 50 to 77 L/hr and lands at 19.7 Wh/L. The 75L uses a single 40-inch membrane for 55 to 82 L/hr, 18.2 Wh/L. The 140L runs two 40-inch membranes for 100 to 154 L/hr and comes in at 9.8 Wh/L. Same pump, same power, half the energy per litre.

One pump, three membrane packs
SystemPowerOutput L/hrDraw WWh per litrePrice
Portable AC 140L
Rainman
AC 240V100–1541,250
9.8
$5,329
Portable AC 75L
Rainman
AC 240V55–821,250
18.2
$4,402
Portable AC 70L
Rainman
AC 240V50–771,250
19.7
$5,296
Under 6 Wh/L · energy recovery
6–12 Wh/L
Over 12 Wh/L

The 12 V and 24 V portables use smaller pumps: 400 W for 34 L/hr and 600 W for 55 L/hr, or 12.7 and 11.3 Wh/L. Still conventional-pump territory, but far kinder to a house bank than the 1,250 W units, and the reason they exist.

Where the whole range makes sense: boats with a genset that make a day's water during the evening engine run, or crews who want a petrol unit on the foredeck for an hour and then want it out of sight. High output in a short window is what Rainman sells. Efficiency per litre is not, and the table says so.

The full Rainman range

SystemPowerOutput L/hrDraw WWh per litrePrice
Portable AC 140L
Rainman
AC 240V100–1541,250
9.8
$5,329
Portable 48VDC 140L
Rainman
48V DC100–1541,250
9.8
$6,240
Modular AC 140L
Rainman
AC 240V100–1541,250
9.8
$5,460
Frame AC 140L, auto
Rainman
AC 240V100–1541,250
9.8
$11,168
Frame AC 140L, manual
Rainman
AC 240V100–1541,250
9.8
$7,685
Frame 48VDC 140L, auto
Rainman
48V DC100–1541,250
9.8
$12,115
Frame 48VDC 140L, manual
Rainman
48V DC100–1541,250
9.8
$8,666
Modular 48VDC 140L
Rainman
48V DC100–1401,250
10.4
$6,421
Portable 24VDC 55L
Rainman
24V DC45–61600
11.3
$4,898
Modular 24VDC 55L
Rainman
24V DC45–61600
11.3
$5,053
Frame AC 240L Torrent, auto
Rainman
AC 240V180–2642,800
12.6
$15,089
Frame AC 240L Torrent, manual
Rainman
AC 240V180–2642,800
12.6
$12,089
Portable 12VDC 34L
Rainman
12V DC26–37400
12.7
$4,898
Modular 12VDC 34L
Rainman
12V DC26–37400
12.7
$5,053
Frame AC 100L, auto
Rainman
AC 240V70–1101,250
13.9
$12,131
Frame AC 100L, manual
Rainman
AC 240V70–1101,250
13.9
$8,642
Portable AC 75L
Rainman
AC 240V55–821,250
18.2
$4,402
Modular AC 75L
Rainman
AC 240V55–821,250
18.2
$4,522
Portable AC 70L
Rainman
AC 240V50–771,250
19.7
$5,296
Modular AC 70L
Rainman
AC 240V50–771,250
19.7
$5,299
Portable Petrol 140L
Rainman
Petrol100–154
petrol
$6,731
Portable Petrol 75L
Rainman
Petrol55–82
petrol
$5,804
Portable Petrol 70L
Rainman
Petrol50–77
petrol
$6,699
Under 6 Wh/L · energy recovery
6–12 Wh/L
Over 12 Wh/L
Where to buy Rainman in Australia
Rainman has the largest verified dealer network in the directory.
See Rainman stockists