M thermal Mono 
202005    7 
Part 1 - General Information 
4 System Design and Unit Selection 
4.1 Selection Procedure 
 
Step 1: Total heat load calculation 
Calculate conditioned surface area 
Select the heat emitters (type, quantity, water temperature and heat load) 
 
Step 2: System configuration 
 
Decide whether to include AHS and set AHS’s switching temperature 
Decide whether backup electric heater is enabled or disabled 
 
Step 3: Selection of outdoor units 
 
Determine required total heat load on outdoor units 
Set capacity safety factor 
Select power supply 
Provisionally select M thermal Mono unit capacity based on nominal 
capacity 
Correct capacity of the outdoor units for the following items: 
Outdoor air temperature / Outdoor humidity / Water outlet temperature
1
 
/ Altitude / Anti-freeze fluid 
Is corrected M thermal Mono unit capacity ≥ Required total heat load on 
outdoor units
2
 
M thermal Mono system 
selection is complete 
Select a larger model or enable 
backup electric heater operation 
Notes: 
1.  If the required water temperatures of the heat emitters are not all the same, the M thermal Mono’s outlet water temperature setting should be set at the 
highest of the heat emitter required water temperatures. If the water outlet design temperature falls between two temperatures listed in the outdoor unit's 
capacity table, calculate the corrected capacity by interpolation. 
2.  If the outdoor unit selection is to be based on total heating load and total cooling load, select Mono units which satisfy not only the total  heating load 
requirements but also the total cooling load requirements.