UAB AMALVA we reserve the right to make changes without prior notice
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4.4. Final Inspection
After installation of the unit, a thorough inspection should be carried out. This should include inspecting the
inside of the unit and removing debris and tools, which may have been left behind by on site contractors. Re-
place any panels, which may have been removed and close all access doors, ensuring that the door sealing
gaskets have not been damaged.
5. MAINTENANCE
It is recommended to carry out routine maintenance of the air handling unit 3–4 times per year. With units
mounted on ceilin do not release the door to the key to open the door. Do not release the door to swing freely,
but open it slowly at a 90 degree angle. Be careful while opening, because clogged filters might fall out.
Besides preventive maintenance inspection, the following operations should be performed:
1. Rotary heat exchanger check.
Inspection of the rotary heat exchanger is performed once per year. Free
rotation of the rotary heat exchanger, continuity of the rotating belt, absence of damages of the rotor drums
and the seal gasket are checked. It is necessary to check the stretch of belt. Free belt will slide and the
efficiency of rotary heat exchanger will fall down. To reach maximal efficiency, rotor must turn at least 8
times per minute. Polluted heat exchanger will decrease efficiency. Clean heat exchanger with an air blast
or wash with tepid water. Check out water falling on the electric motor.
2.
Plate heat exchanger check.
Inspection and dedusting of the plate heat exchanger is performed once per year
(it is removed from the unit and blown with an air blast or washed with tepid water).
Plate heat exchanger cleaning.
If plate heat exchanger cleaning by compressed air is not effective, it can
be washed with soapsuds, or if needed – use degreasing soak for metal (aluminum) cleaning. Leave plate
heat exchanger to dry in a warm place. It can be mounted only when it is absolutely dry.
Note:
plate heat exchanger may be replaced with summer cassette (for units without by pass), when recupera-
tion is needless.
3. Fans check (once per year).
Polluted fans decrease efficiency.
Before performing any inspection work, check whether the unit is
switched off from the electric power supply.
Fans should be carefully cleaned with textile or soft brush. Do not use water. Do not break balance. Check
if direction of fan turns is right, because wrong direction of turns gives only 30 % rating. Check if fan freely
rotates and is not mechanically damaged, if impeller does not touch suction nozzles, fan does not spread
noise, the pressure tubes are connected to the nozzle (if it is required), mounting bolts are screwed.
The rubber couplings connecting the motor base and the unit should be visually inspected for signs of wear
and replaced as necessary.
Any unusual noise or vibration when the fan is running should be immediately investigated, as this usually
an indication of wear or imbalance in the fan system.
4. Air heater check.
Recommended to perform periodical inspection and cleaning of heater. Check the plates
of water air heater. The air heater is cleaned with hoover from supply air side or with air blast from exhaust
air side. If it is very dirty, wash with tepid water, which will not make corrosion of aluminium. Check if position
of return water temperature sensor is right. Check if electric air heater is properly fixed, wires connections
are not damaged and heating elements are not bent. They can be damaged or bent due to uneven heat or
uneven and turbulent air direction. Check if electric air heater is clear of unnecessary things and heating
elements are not clogged, because this can cause unpleasant smell or in the worst case – dust can start
burning. Air flow through the air heater should be greater than 1,5 m/s. Heating elements can be cleaned
with hoover or wet textile.
5. Air damper check (if it is required).
Not fully opened outside air damper rises up the pressure in the sys-
tem. Water air heater can freeze if outside air damper does not fully close in not working air handling unit.
Mounting and running of air damper should be checked and regulated.
6. Air filter clogging check.
Change air filters when air filter clogging is indicated. We recommend changing
filters at least twice per year: before and after heating season or more
1
.
Filters are one time used. We do not recommend cleaning them. Stop the air handling unit before changing
filters.
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Clogged filters unbalance ventilation system, air handling unit uses more power.
