8
INDOOR INSTALLATION
1. Follow all local codes, or in the absence of local
codes, follow the most recent edition of the National
Fuel Gas Code: ANSI Z223.1/NFPA 54 in the USA
or CAN/CSA B149.1 Natural Gas, Propane
Installation Code in Canada.
Keep the clearances.
2. When installed indoors, the Hydro-Smart 170 shall
be located in an area to maintain the following
minimum clearances around the unit:
Side 2”
Side 2”
Back 1”
Top 12”
Front 4”
(24” Recommended
for Maintenance)
Bottom 12”
Combustion Air Supply
The Hydro-Smart 170 location must provide enough air for proper combustion and ventilation of
the surrounding area. See the latest edition of ANSI Standard Z223.1 or any applicable local
codes. In general, these requirements specify that if the unit is installed in a confined space,
there must be a permanent air supply opening.
Minimum recommended air supply opening size for Hydro-Smart 170:
Hydro-Smart 170
size
When drawing
make-up air from
outside the building
When drawing make-up
air from inside
the building (from other rooms within)
13.3 Sq. IN 199 Sq. IN
MAX 199,000 BTU
When combustion air is supplied
from outside the building, an
opening communicating directly
with the outside should have a
minimum free area of one
square inch per 15,000 BTUH
input of the total input rating of
Hydro-Smart 170 in the
enclosed area.
When combustion air is supplied from
inside the building, an opening
communicating with the rest of the
dwelling should have a minimum free
area of one square inch per 1,000
BTUH input of the total input rating of
Hydro-Smart 170 in the enclosed
area. This opening should never be
less than 199 sq. in.
Combustible Air Supplied by Mechanical fan or Make up air device
The Hydro-Smart 170 is equipped with a combustible air sensor that will shut off the unit when
inadequate combustible air supply to unit is detected.
• If a mechanical fan or make up air device is used to supply air to the Hydro-Smart 170 or
utility room, the installer should make sure it does not create drafts which could cause
nuisance shutdowns.
• If a blower is necessary to provide adequate combustion air to the Hydro-Smart 170, the
blower and Hydro-Smart 170 must be set up so that the Hydro-Smart 170 cannot fire
unless the blower is operating. Possible methods include the use of external flow
sensors/transmitters and relays.
