IN115 RevA v1
4
3 Saber Way, Ward Hill, MA 01835 | radonaway.com
The use of small diameter piping in a system increases the speed at which the air moves. The speed of the air can
pull water uphill and, at sufficient velocity, it can actually move water vertically up the side walls of the pipe. This
has the potential of creating a problem in the negative pressure (inlet) side piping. For HS2750 or HS5500 Blower
inlet piping, the following table provides the minimum recommended pipe diameters as well as minimum pitch
under several system conditions. Use this chart to size piping for a system.
All exhaust piping should be 2” PVC.
1.6 SYSTEM MONITOR & LABEL
A properly designed system should incorporate a “System On” indicator for affirmation of system operation. The
HS2750 and HS5500 Blowers come equipped with a built-in magnehelic pressure gauge located on the front
cover which serves this purpose. Other indicator products such as u-tube manometers should be mounted at least
5 feet above the slab penetration to minimize the risk of filling the gauge with water in installations with occasional
high water tables. If required, place in a conspicuous location a System Label (such as RadonAway P/N 15005-
20) with instructions for contacting the installing contractor for service and also identifying the necessity for regular
radon tests to be conducted.
1.7 SLAB COVERAGE
The HS2750 or HS5500 Blower can provide coverage of well over 1000 sq. ft. per slab penetration. This will, of
course, depend on the sub-slab aggregate in any particular installation and the diagnostic results. In general, sand
and gravel are much looser aggregates than dirt and clay. Additional suction points can be added as required. It is
recommended that a small pit (5 to 10 gallons in size; larger as needed) be created below the slab at each suction
hole. When fine sand or dirt is present it is recommended that the pit be lined with a material such as clean gravel,
size 4, 5, 56, or 6 as classified (ASTM C33).
1.8 ELECTRICAL WIRING
HS2750 or HSHS5500 Blower models come with an electrical switch box for hard wiring to a 120V electrical
source. All wiring must be performed in accordance with the National Fire Protection Association’s (NFPA)”National
Electrical Code, Standard #70”-current edition for all commercial and industrial work, and state and local building
codes. All wiring must be performed by a qualified and licensed electrician. Outdoor installations require the use
of a UL listed watertight conduit. Ensure that all exterior electrical boxes are outdoor rated and properly caulked to
prevent water penetration into the box. A means, such as a weep hole, is recommended to drain the box.
WIRING DIAGRAM
1.9 SPEED CONTROLS
The HS2750 and HS5500 have 4-speed (low, medium, high, maximum) built-in speed controls. They are not safe
for use with solid state speed controls.
*Typical operational flow rates:
RUN
RISE
Pipe
Diameter
Minimum Rise per 1 Foot of Run*
@ 25 CFM
@ 50 CFM
@ 100 CFM
4”
1/32”
3/32”
3/8”
3”
1/8”
3/8”
1 1/2”