Enertech Global
75
EAV - EME/EMD Rev. A Models
Installation and Operations Manual
Outdoor Air Temperature (OAT)
The OAT terminals in the EME/EMD indoor module are not used.
The out door sensor is installed and wired in the Outdoor Unit,
Sensor BT28.
Outdoor reset control will vary the design load temperature
based on outdoor temperature. The colder the outside
temperature, the warmer the load water/antifreeze solution
temperature. This offers several advantages. The COP of the
system is improved by targeting the lowest outlet temperatures
possible. Additionally, user comfort is improved by maintaining
ideal temperatures for the current outdoor conditions. If
necessary, the EAV can operate without outdoor reset by setting
a static load water/antifreeze solution temperature (see Section
9).
Note:
The outdoor temperature is a running one hour average
to avoid dramatic shifts.
The EAV utilizes a set of temperature curves as seen in Figure
21. The default curve is #3 and has been found to work in
many installations. Depending on the load calculation and
environmental requirements, a different curve may be
preferable: The higher numbered curves produce higher radiant
floor temperatures for a given outdoor temperature while
the lower numbered curves produce lower temperatures. For
example, at 30°F outdoor temperature, curve #3 will produce
79°F outlet temperature. Changing to curve #4 would produce
84°F outlet at that same condition.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
59
69
79
89
99
109
119
129
139
-30
-10
10
30
50
70
Supp
ly
T
em
ep
ra
tu
re
°F
Outdoor Temperature °F
Hea
ti
ng Curves
⚠
NOTICE
⚠
Flooring manufacturers may have maximum recommended
temperatures for radiant heat. This can be established on the
HMI to cap the highest possible load temperature, regardless
of outdoor temperatures.
Human Comfort Exposure Limits
Max. Temperature, deg. F
Floors occupied in areas
85
Floors in perimeter areas
95
Floors in bathrooms
91
Floors in hallways, secondary
rooms
95
Table 8: Max Temperatures Through Various Types of Flooring
Figure 21: Heating Curves (Outdoor Temperature Reset)
Section 9: On-Board Controls
