Instruction Manual
58 
Refrigerant-to-Water Heat Exchanger 
Condenser  water  pump,  condenser  water 
piping, cooling tower  or geothermal loop, 
pressure gauges, strainers, piping insulation 
and all components of the waterside piping 
must be field installed. 
Water-Source Heat Pump Applications 
Water-source  heat  pump  units  using  100% 
outside air must have electric preheat if the 
application has a potential for operation with 
air entering the indoor coil below 43°F with 
a water loop temperature of 70°F. 
Open Loop Applications 
This  product  contains  one  or  more 
refrigerant-to-water  heat  exchangers  made 
of 316 Stainless Steel. 316 Stainless Steel is 
subject to severe corrosion and failure when 
exposed to chlorides. 
Do not allow water containing any form of 
chlorides to enter this heat exchanger. 
Common forms of chlorides include: 
1. Sea water mist entering an open cooling 
tower system. 
2. Contaminated makeup  water containing 
salt water. 
3. Disinfecting the water loop with solutions 
containing sodium hypochlorite. 
Chlorides  will  result  in  a  premature  failure 
of the condenser. 
Failure  of  the  condenser  as  a  result  of 
chemical  corrosion  is  excluded  from 
coverage  under AAON  warranties  and the 
heat exchanger manufacturer warranties. 
Failure of the condenser will allow water to 
enter  the  refrigerant  circuit  and  will cause 
extensive  damage  to the  refrigerant  circuit 
components. Any damage to the equipment 
as  a  result  of  condenser  failure  from 
chemical  corrosion  due  to the  fluid in  the 
condenser is excluded from coverage under 
AAON warranties and the heat exchanger 
manufacturer warranties. 
OPEN LOOP APPLICATIONS 
SMO  254  brazed  plated  refrigerant-
to-water  heat  exchangers  are 
recommended  with  all  open  loop 
applications. Failure to use  a SMO 
254  heat  exchanger  may  result  in 
premature failure of your system and 
possible voiding of the warranty. 
   WARNING 
OPEN LOOP APPLICATIONS 
Failure  of  the  condenser  as  a  result 
of  chemical  corrosion  is  excluded 
from  coverage  under  AAON  Inc. 
warranties  and  the  heat  exchanger 
manufacturer’s warranties. 
   WARNING 
WATER-SOURCE HEAT 
PUMP APPLICATIONS 
Water-source  heat  pump  units using 
100%  outside  air  must  have  electric 
preheat  if  the  application  has  a 
potential  for  heat  pump  heating 
operation with air entering the indoor 
coil  below  43°F  with  an  entering 
water loop temperature of 70°F. 
   CAUTION  










