Enertech AV Series - Monobloc Requirements

Enertech Global, LLC 36
AV : MD/ME - Rev. A Models
Installaon and Operaons Manual
Monobloc Requirements
The EAV unit is a monobloc design, which means that the
refrigerant circuit is completely contained in the outdoor
unit and therefore no refrigerant line set is required. Piping
between the outdoor unit and indoor module includes
a water/anfreeze mixture that must have sucient
concentraon of anfreeze not only for freeze protecon
to keep the soluon from freezing while operang, but also
sucient burst protecon for mes where power may be
interrupted to the unit during extremely cold temperatures.
Enertech recommends Fernox Alphi-11 propylene glycol
anfreeze in all systems where the minimum outdoor
temperature is below freezing and/or in systems that
are making chilled water for cooling applicaons. This is
a warranty requirement. The following table provides
guidelines for determining the correct amount of anfreeze.
Enertech recommends using the 20 year Extreme Annual
Temperature shown in the ASHRAE Fundamentals Handbook,
Environment Canada, or local weather data.
Concentra-
on
25% 30% 35% 40% 45% 50%
Protecon
O
F 12.2 5 -0.4 -7.6 -16.6 -29.2
Burst Point
O
F 0 -20 -40 -60 -70 -80


Extreme Annual Temperature,
deg F
Period Values of Extreme Temperature, deg F
Mean
Standard De-
viaon
5 years 10 years 20 years 50 years
Min Max Min Max Min Max Min Max Min Max Min Max
-3.2 90.5 7.5 3.9 -8.6 93.2 -13.1 95.5 -17.3 97.7 -22.8 100.5
Example:
The following table shows the Extreme Annual Temperature
for Chicago at -17.3 deg F. For adequate burst protecon, a
concentraon of 30% Alphi-11 should be used to protect the
system.
In most areas of North America, 25% to 30% is sucient
for burst protecon. In Northern U.S. and some Canadian
climates, 35% or more must be used. Enertech recommends
25% or higher concentraon, depending upon locaon.
Lower concentraon provides beer heat transfer and lower
viscosity, but may not provide enough burst protecon.
Secon 6: Anfreeze