Heating Sizing Chart Guide
Use this guide to give you an approximate unit size.

Units should not be purchased without an in-home quote being completed by a qualified
Mitsubishi Electric Authorised Dealer.

Every home is as individual as its owner. The key to selecting the right heat pump for heating your home is to choose
the correct unit size. Choosing the wrong unit could cost you more in power consumption. You can use this guide to
give you an approximate unit size, but the correct calculation needs to be carried out by a qualified specialist.
New or Well Insulated House:
| Room Size |
 |
Ceiling Height |
 |
Factor |
 |
Kw Heating |
 |
Wall Inverter |
 |
Deluxe Wall Inverter |
 |
Floor Inverter |
 |
Ceiling Cassette Inverter |
 |
Ceiling Concealed Inverter |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| 4x3m Room |
2.4m Ceiling = 28.8m³ |
x 55watts per m³ = |
1.6 Kw |
MSZ-GE25VA* |
MSZ-FB25VA* |
MFZ-KA25VA* |
SLZ-KA25VA / VAL* infra-red |
SEZ-KD35VA* |
| 4x4m Room |
2.4m Ceiling = 38.4m³ |
x 55watts per m³ = |
2.1 Kw |
MSZ-GE25VA* |
MSZ-FB25VA* |
MFZ-KA25VA* |
SLZ-KA25VA / VAL* infra-red |
SEZ-KD35VA* |
| 4x5m Room |
2.4m Ceiling = 48.0m³ |
x 55watts per m³ = |
2.6 Kw |
MSZ-GE25VA* |
MSZ-FB25VA* |
MFZ-KA25VA* |
SLZ-KA25VA / VAL infra-red |
SEZ-KD35VA* |
| 5x5m Room |
2.4m Ceiling = 60.0m³ |
x 55watts per m³ = |
3.3 Kw |
MSZ-GE25VA |
MSZ-FB25VA |
MFZ-KA25VA |
SLZ-KA35VA / VAL infra-red |
SEZ-KD35VA* |
| 6x5m Room |
2.4m Ceiling = 72.0m³ |
x 55watts per m³ = |
4.0 Kw |
MSZ-GE35VA |
MSZ-FB35VA |
MFZ-KA35VA |
SLZ-KA35VA / VAL infra-red |
SEZ-KD35VA |
| 6x6m Room |
2.4m Ceiling = 86.4m³ |
x 55watts per m³ = |
4.7 Kw |
MSZ-GE50VA |
MSZ-FB50VA |
MFZ-KA50VA |
SLZ-KA50VA / VAL infra-red |
SEZ-KD50VA |
| 6x7m Room |
2.4m Ceiling = 100.8m³ |
x 55watts per m³ = |
5.5 Kw |
MSZ-GE50VA |
MSZ-FB50VA |
MFZ-KA50VA |
- |
SEZ-KD50VA |
| 7x7m Room |
2.4m Ceiling = 117.6m³ |
x 55watts per m³ = |
6.5 Kw |
MSZ-GE60VA |
- |
- |
- |
SEZ-KD60VA |
| 7x8m Room |
2.4m Ceiling = 134.4m³ |
x 55watts per m³ = |
7.4 Kw |
MSZ-GE71VA |
- |
- |
- |
SEZ-KD71VA |
| 8x8m Room |
2.4m Ceiling = 153.6m³ |
x 55watts per m³ = |
8.4 Kw |
MSZ-GE80VA |
- |
- |
- |
- |
 Note: * Higher rated unit for application, but can be used. |
Cold Damp House or Lots of Glass:
| Room Size |
 |
Ceiling Height |
 |
Factor |
 |
Kw Heating |
 |
Wall Inverter |
 |
Deluxe Wall Inverter |
 |
Floor Inverter |
 |
Ceiling Cassette Inverter |
 |
Ceiling Concealed Inverter |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
| 4x3m Room |
2.4m Ceiling = 28.8m³ |
x 65watts per m³ = |
1.9 Kw |
MSZ-GE25VA* |
MSZ-FB25VA* |
MFZ-KA25VA* |
SLZ-KA25VA / VAL* infra-red |
SEZ-KD35VA* |
| 4x4m Room |
2.4m Ceiling = 38.4m³ |
x 65watts per m³ = |
2.5 Kw |
MSZ-GE25VA* |
MSZ-FB25VA* |
MFZ-KA25VA* |
SLZ-KA25VA / VAL infra-red |
SEZ-KD35VA* |
| 4x5m Room |
2.4m Ceiling = 48.0m³ |
x 65watts per m³ = |
3.1 Kw |
MSZ-GE25VA |
MSZ-FB25VA |
MFZ-KA25VA |
SLZ-KA25VA / VAL infra-red |
SEZ-KD35VA* |
| 5x5m Room |
2.4m Ceiling = 60.0m³ |
x 65watts per m³ = |
3.9 Kw |
MSZ-GE35VA |
MSZ-FB35VA |
MFZ-KA35VA |
SLZ-KA35VA / VAL infra-red |
SEZ-KD35VA |
| 6x5m Room |
2.4m Ceiling = 72.0m³ |
x 65watts per m³ = |
4.7 Kw |
MSZ-GE50VA |
MSZ-FB50VA |
MFZ-KA50VA |
SLZ-KA50VA / VAL infra-red |
SEZ-KD50VA |
| 6x6m Room |
2.4m Ceiling = 86.4m³ |
x 65watts per m³ = |
5.6 Kw |
MSZ-GE50VA |
MSZ-FB50VA |
MFZ-KA50VA |
- |
SEZ-KD50VA |
| 6x7m Room |
2.4m Ceiling = 100.8m³ |
x 65watts per m³ = |
6.5 Kw |
MSZ-GE60VA |
- |
- |
- |
SEZ-KD60VA |
| 7x7m Room |
2.4m Ceiling = 117.6m³ |
x 65watts per m³ = |
7.6 Kw |
MSZ-GE71VA |
- |
- |
- |
SEZ-KD71VA |
| 7x8m Room |
2.4m Ceiling = 134.4m³ |
x 65watts per m³ = |
8.7 Kw |
MSZ-GE80VA |
- |
- |
- |
- |
 Note: * Higher rated unit for application, but can be used. |
Downloadable version, includes models:
(July 2009): 1 page guide, includes:

Inverter Heat Pumps -
High Wall: MSZ-GE25VA, MSZ-GE35VA, MSZ-GE50VA, MSZ-GA60VA, MSZ-GA71VA, MSZ-GA80VA, MSZ-FB25VA, MSZ-FB35VA, MSZ-FB50VA.
Compact Floor: MFZ-KA25VA, MFZ-KA35VA, MFZ-KA50VA, MFZ-KA25VA-RC, MFZ-KA35VA-RC, MFZ-KA50VA-RC.
Compact Ceiling Cassette: SLZ-KA25VA, SLZ-KA35VA, SLZ-KA50VA, SLZ-KA25VAL, SLZ-KA35VAL, SLZ-KA50VAL.
Heating Sizing
Chart Guide.pdf (101KB)
Sizing Guidelines:
Guideline for sizing Heat Pumps (Low ambient conditions) - Pdf Format (457Kb)
16 page guide: The purpose of this guide is to ensure that heat pumps installed primarily for
heating purposes in areas subject to low ambient conditions are correctly sized, selected, and applied
to ensure heating performance that will satisfy the end users requirements.
Location:
Indoors:
Don’t locate with obstructions in front.
Result:
Short cycling of air back to units room sensor.
Air is not circulated correctly leaving cold areas in room.
Try to locate the indoor unit where the airflow is pointing to the other areas of the house that may require residual heating.
Outdoors:
Avoid paved areas unless a drain kit is fitted.
Result: Units condensate and drip water. May cause slime build up or ice.
If no other place please advise customer.
Inverter System or Fixed Speed System?
What is a Fixed Speed Split System?
This system only has a single speed compressor motor that is either on or off.

It works similar to a fan heater that switches off when the desired temperature is
reached and on again when the temperature drops to a set level.
What does Inverter Mean?
Inverter technology uses a variable speed compressor motor similar to a car. It simply slows down
and speeds up as needed to hold a selected comfort setting.

Inverter technology provides a more precise room temperature without the temperature fluctuations
of fixed speed systems.
Inverter vs Standard:
Inverter Systems are Approximately 30% more efficient than fixed speed systems.

Inverter systems reach desired room temperature quicker.

The speed control of the outdoor unit also means quieter operation, this is important
especially at night in residential areas.
 |
 |
Inverter Systems
- Increased output to achieve set temperature faster.
- Then varies the output to maintain a constant room temperature.
|
 |
 |
Fixed Speed Type
- Slowly gets to temperature as output rating is fixed.
- Then turns on and off to maintain room temperature.
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