Unico V2430 Скачать руководство пользователя страница 6

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Bulletin 30-015.003

Page 6

Figure 4 Supply plenum adapter, square duct

To attach the plenum adapter to the unit, align the
holes on the adapter with the holes located around the
supply outlet on the unit. Mount the adapter with eight
(8) sheet metal screws.

For  metal  duct,  attach  the  plenum  to  the  adapter  by
inserting  it  over  the  collar.  Use  three  (3)  or  four  (4)
equally spaced sheet metal screws to secure the duct to
the collar and then tape around the seam with UL 181A
aluminum  tape. Then  wrap  the  1-in  fiberglass  blanket
duct  insulation  around  the  adapter  and  seal  with  UL
181A aluminum tape.

Other size plenum may be used provided it is similar in
cross-sectional area. Refer to the design manual for
alternate sizes.

Return Duct

The Unico return air system typically has a single return
that includes the return air box with filter, the acoustical
flex  return  duct,  and  the  return  air  adapter.  Multiple
returns or extra-long returns are possible so long as the
maximum  pressure  loss  is  not  exceeded.  The  return
system is designed for a maximum static pressure drop
of 0.15 inches of water (37 Pa) including the filter. The
return  duct  should  have  at  least  one  90  degree  bend
between  the  unit  and  filter  box  to  reduce  sound
transmission directly from the unit.

The  return  air  must  always  enter  the  unit  from  the
bottom. Set the unit on a field fabricated duct (figure 5)
or use a field supplied plenum base. If using a duct, be
sure  that  the  inside  of  the  duct  is  insulated  with
acoustical  insulation  (typically  duct  liner).  The
minimum height of the plenum duct is shown in figure
5.

Figure 5 Minimum duct return

Although Unico only supplies a single return system,
the return system can be redesigned for multiple
returns. The return duct system is not high velocity.
Therefore, the return system static pressure should not
exceed 0.15 inches of water column. Generally, this
means sizing the duct for a pressure loss of 0.05 inches
of water column at the required airflow and sizing the
filter for a pressure drop of 0.10 inches of water
column at the required airflow.
It  should  also  have  some  form  of  sound  attenuation.
Sound attenuation can be accomplished with fabricated
duct  board,  lined  sheet  metal,  or  acoustical  flex.  For
best  attenuation,  always  have  at  least  one  90  degree
bend to eliminate direct line-of-site from the unit to the
return opening.

AIR FILTRATION

The unit includes a 1 inch (25 mm) thick pleated filter
(Table  2).  You  can  remove  this  filter  (Figure  6)  and
replace  it  with  a  2”  filter  or  install  another  filter
elsewhere in the system. See figure 7 and table 3 for a
plenum base concept and filter size.

Table 2 Unit Filter Size, 1 inch (25 mm)

Model

Filter Part No.

Dimensions, inch (mm)

2430

A00558-005

18 x 18 (457 x 457)

3036

A00558-008

18 x 22 (457 x 559)

3642

A00558-009