Supply Air Temperature Control And Compensation; Fan Control; Boost" Function; Weekly Schedule - Salda Smarty Rv Series Montage-Und Installationsanleitung

Inhaltsverzeichnis

7.4.5. SUPPLY AIR TEMPERATURE CONTROL AND COMPENSATION

Temperature for supply air or premises temperature may be indicated. In the service environment section SERVICE › MAIN › SUPPLY AIR TEMPERATURE CONTROL you

can control it based on supply or exhaust air temperature. If control by premises temperature is selected, then it is calculated what kind of air is to

be supplied so that the proper room temperature is maintained. It is limited by allowable limits of supply air temperature.

The air handling unit is not designed to heat premises, therefore it is not necessary to use full capacity for low temperature differences – the

compensation in percentage is provided for this purpose. This parameter indicates a percentage of the temperature difference (between the set

temperature and premises temperature) to be compensated for by this function. E.g. set point is 20 °C, temperature in the premises is 16 °C,

compensation is 50 %, difference between the indicated and existing temperatures is 20-16=4 °C. Since 50 % is compensated, then 4*50 %=2

°C. When the received value is added to the set temperature we get the required supply air temperature – 2+20=22 °C. This temperature is not

limited as it is within the supply air temperature protection limits. In this case the system maintains the supply air temperature at 22 °C. The closer

the premises temperature is to the set temperature (20 °C), the faster the supply air temperature reaches 20 °C.

It may be too hot in the premises, therefore this function both heats and cools. Preferred (compensated) temperature is displayed in the window

MONITORING (REQUIRED SUPPLY). If the displayed temperature is 0 °C, it means that temperature maintaining of supply air is switched off.

The temperature of supply air is maintained by the following components (indicated in a sequential order):

• Fans (operate slower, if it is too hot);

• Recirculation valve (if the ambient air temperature is favourable);

• Water cooler;

• DX cooler;

• Recirculation damper and CO

• Bypass damper or rotor (in case of favorable outdoor temperature);

• Recirculation damper and CO

• DX heater;

• Water heater;

• Water cooler/heater;

• Electrical heater;

• Fans (operate slower, if it is too cold).

Firstly the system tries to maintain the supply air temperature by means of a heat exchanger. In case of a plate heat exchanger, the bypass damper

is controlled, and in case of a rotary heat exchanger, the rotor rotating speed or interval is changed. The heat exchanger can both heat and cool –

it depends on outdoor and room air temperatures. It is controlled by a PID controller whose coefficients are indicated in the adjuster environment

section ADJUSTER › PID CONTROLLERS ADJUSTING › HEAT EXCHANGER CONTROL BY SUPPLY AIR TEMPERATURE.

When the heat exchanger operates at full capacity and preferred temperature is not reached, the recirculation damper, then the heater or cooler

etc. is activated (if necessary). Only the components configured for temperature maintaining are activated. It takes 10 s for the system to switch

between the elements.

7.4.6. FAN CONTROL

The preferred air-flow can be indicated in percentage or in 4 fixed speeds where each of them is dedicated to a relevant system mode:

• Building protection;

• Economy;

• Comfort;

• Maximum power.

Fan speed can be controlled by:

• Percentage - speed in percentage is indicated in the adjuster environment window ADJUSTER › AIR FLOWS ADJUSTING: 0 % corresponds to 0, and 100

% – 10 V control signal voltage;

• Pressure - the maximum system pressure is indicated, which based on speed settings in the adjuster environment ADJUSTER › AIR FLOWS ADJUSTING

means 100 % air-flow;

• Air-flow (m

/h) - K factors of supply and exhaust air and the maximum system air-flow (m

the adjuster environment ADJUSTER › AIR FLOWS ADJUSTING means 100 %.

Fans based on air-flow and pressure are controlled by PID controller and its coefficients are indicated in the adjuster environment section ADJUSTER

› PID CONTROLLERS ADJUSTING › FANS SPEED CONTROL BY AIR FLOW OR PRESSURE. Each fan is controlled individually.

In the service environment window SERVICE › FANS › FANS SPEED CONTROL you can limit the minimum and maximum fan control signal voltage. Based on

manufacturer set parameters, the minimum 2V voltage is indicated, which means that 0V voltage signal is sent when fans are off, and 2V voltage

signal is immediately switched on when rotation is required.

It is possible to specify the nominal flows of supply and exhaust air. Then, the maximal air flow is calculated automatically.

7.4.7. "BOOST" FUNCTION

Boost ventilation function is used for fast ventilation of premises. It activates the maximum air-flow (speed 4). Boost ventilation has be temporary,

i.e. it must be a final condition (e.g. CO

dry air is harmful for health.

The function is activated by pressing ON and deactivated by pressing OFF button in the BOOST section, or by means of an external contactor

(FANS SPEED SWITCH), which is configured in the service environment (SERVICE › MAIN › FANS SPEED SWITCH) section.

The function is inactive when Stand-by mode is on. Time limit is indicated (ADJUSTER › USER SETTINGS › BOOST TIMER or USER › MENU › SETTINGS › BOOST TIMER). Once the

function is activated, the time is set by the timer and the time is counted till its deactivation. It may be adjusted in real-time, i.e. when the function

is on, in ADJUSTER › VENTILATION CONTROL or in the user environment main window.