
AccuWIN
Obtains optimum performance from your heating system
Convenient and variable use
- Different accumulator types and sizes can be connected
- Can be used in niches because of the forward-pointing connections
- Tank temperatures can be easily read off the tank
- Can be combined with fresh water module FRIWA30
Efficient
- Best thermal insulation due to 100 mm fleece insulation
- Unique, patented connection between two buffer tanks
- Covers as standard to reduce radiation
Reliable and safe
- Long service life thanks to quality steel and powder coating
- Resistant polystyrene jacket

Fleece insulation
Up to 36 % less heat loss compared with expanded foam insulation. Made of 70 % recycled material and already satisfies future EU requirements.
Connections pulled up and down
Best use of energy is gained by taking out the heating water at its highest temperature (top) and also loading the bottom part not normally used.
Hooked strip
Quick and easy installation and a clean look since the cable duct has several functions.
6/4" connections
Requires little space and can be used in niches because of the forward-pointing connections.
Indicating thermometer
3 indicating thermometers allow the buffer tank temperatures to be easily read off at the top, middle and bottom.
AccuWIN
Well-designed to the smallest detail
Fleece insulation
Up to 36 % less heat loss compared with expanded foam insulation. Made of 70 % recycled material, AccuWIN already satisfies future EU requirements.
Indicating thermometer
3 indicating thermometers allow the buffer tank temperatures to be easily read off at the top, middle and bottom.
6/4" connections
Requires little space and can be used in niches because of the forward-pointing connections.
Hooked strip
Quick, easy installation and a clean look since the cable duct has several functions.
Connections pulled up and down
The best use of energy is gained by taking out the heating water at its highest temperature (top), and also loading the bottom part which is not normally used.
AccuWIN
Unique, patented cascading
Small, but highly efficientPerfect heat management and best possible use of energy are the priorities of the new AccuWIN heat accumulator range.
With innovative combination and loading technology, Windhager will be able to utilise stored heat even more efficiently in future. To this end, the buffer tanks are connected both parallel and diagonally. This means the solar yield is significantly greater than in conventional solutions, and above all in buffer cascades with only one solar accumulator.
Method of operation: loading
Step 1: loading
First of all, only the AccuWIN Solar is loaded as a result of the buffer loading control and the hydraulic arrangement.
Advantages for you:
- Quickly achieves a usable temperature level, because only a small volume of water (approx. 50 – 70 l) needs to be heated.
- Lower radiation losses, because only the AccuWIN Solar is heated up.

Step 2: loading the 2nd accumulator
A valve opens as soon as the temperature in the area of the solar accumulator's connecting pipe reaches 45 °C. The second buffer tank is loaded without any auxiliary energy whatsoever, due to thermal circulation.
Advantages for you:
- Loading of the second buffer tank (AccuWIN) without additional auxiliary energy
- The bottom part of the solar accumulator (AccuWIN Solar) remains available for potential solar yield up until the point when it has been fully loaded.

Step 3: both accumulators fully loaded
If sufficient energy is supplied (e.g. from a split log boiler) then both accumulators (AccuWIN Solar and AccuWIN) are fully loaded.

Method of operation: unloading
Step 1: unloading
During unloading, precedence is given to energy from the solar accumulator.
Advantages for you:
- Rapidly available area (bottom) in the AccuWIN Solar for possible solar yield.
- Optimum temperature stratification in both accumulators at all times, because the return goes straight into the AccuWIN Solar via the bottom connection. In contrast to a serial connection, this avoids the second buffer tank having to be passed through.

Step 2: reverse unloading
If the temperature in the AccuWIN Solar (left) drops below that of the AccuWIN (right), the heat gradient in the first accumulator is changed around using a pump.
Advantage for you:
- Optimum temperature stratification is maintained

AccuWIN
Technical data
The AccuWIN is available in three different forms. We have provided an overview of the technical data.
Type | AccuWIN 825 | AccuWIN 1000 | AccuWIN 1500 | |
---|---|---|---|---|
Nominal content | l | 825 | 1.000 | 1.500 |
Diameter with/without insulation | mm | 990/790 | 990/790 | 1.200/1.000 |
Height with/without insulation | mm | 1.940/1.860 | 2.135/2.050 | 2.235/2.150 |
Overall height without insulation | mm | 1.905 | 2.090 | 2.270 |
Minimum room height | mm | 1.960 | 2.190 | 2.290 |
Weight with/without insulation | kg | 120/110 | 140/130 | 220/205 |
Supply and return connections | Int./ext. thread | 6/4“ IG | 6/4“ IG | 6/4“ IG |
Connection ports | Int./ext. thread | 6/4“ IG | 6/4“ IG | 6/4“ IG |
Max. permissible operating pressure for heating | bar | 3 | 3 | 3 |