recair sensitive RS160
saving energy in comfort
recair sensitive RS160 width 366 mm
Recair Sensitive is a unique, patented recuperator specially designed for air-to-air heat recovery in balanced ventilation systems for homes and offices. It is a true breakthrough in ventilation technology, making it possible to recover and efficiently reuse energy generated for heating or cooling rooms, while optimising the ventilation that is so crucial for a healthy, indoor climate. Recair Sensitive can be used in almost any ventilation system to maximise indoor comfort and air quality while substantially reducing basic energy requirements and costs. This benefits end-users by increasing their wellbeing and reducing their energy bills. And, by reducing the need for fossil fuels, it also benefits our environment.
128,5º
height 194 366 3 mm mm m
The Recair recuperation principle Good ventilation is very important, but when the outside air temperature differs considerably from the indoor air temperature, ventilation results in a great deal of energy loss. The key to Recair recuperation technology is that it enables and maximises the exchange of energy between the incoming and outgoing airflows before the energy dissipates in the atmosphere. Optimum recuperation (i.e., 100% thermal effectiveness) is achieved when the air temperature at the end of the cooling trajectory is equal to the counterflow at the beginning of the heating trajectory, and vice versa. It is impossible to realise this ideal situation in practice, but Recair Sensitive makes it possible to achieve thermal effectiveness of between 90-98%, thanks to its unique, patented design.
width 366 mm
128,5º height 194 366 386 mm mm mm
length 150 - 500 mm
8 mm
fig. 2 Dimensions.
fig. 1 Triangular ducts principle.
The triangular ducts in the recuperator are arranged so that each one is surrounded by parallel ducts in which the air is in counterflow (see Fig. 1). Each fresh-air duct is surrounded by three ducts filled with warmer exhaust air. Likewise, each duct with exhaust air is surrounded by three fresh-air ducts. This maximises the surface area over which energy can efficiently be transferred, recaptured and reused. This design principle is what makes the Recair Sensitive’s outstanding performance possible. In comparison with conventional cross-flow recuperators of the same size, the Recair Sensitive’s thermal effectiveness is at least 33% better. The unique duct system design even gives the Recair Sensitive an advantage over counterflow plate recuperators: with air-flow space being the same, it has a heat exchange capacity that is almost 3,5x higher.
length 150 - 500 mm
8 mm Construction and dimension
The Recair Sensitive can be used for air temperatures between -30 and +50 ºC. The recuperator is constructed completely from polystyrene - from the foils to the casing. Only solvent-free elastic adhesives are used. The Recair Sensitive has a width and height of 366 mm, and the length can vary from 100 mm to 500 mm (see Fig. 2). It is also possible for several recuperators to operate in parallel. The largest recuperator (500 mm) weighs 5 kg, and has a heat exchange surface of ±36 m2, and a volume of 51 liters.
dry air
100
dry air
100 99
300
250 200 150
0,2
250 0,3
200 150
100
100
50
50
0
0 0
0,1
95
0,2 90
90
85 0,3 80
0,4
0,4
0,5
0,5
75
85 0,5 80
70
0,1
96 95
93 0,4
0,3
92 0,3 91 0,2
40
0,5 94
0,4
0,1 0,2
60
20 0
90
98 97
80 60
96 95
40
94 93 92 91
20 0
90
0 200 50 100 250 150 300 200 350 400 250 450 300 500 350 400 450 500 50 100 150 0 200 50 100 250 150 300 200 350 250 400 300 450 500 350 400 450 0 500 50 100 150 -20 -15 -10 -20 -5 -15 0 -10 5 length (m) 0,1 0,2 0,30,10,40,20,50,3
length (m) 0,4
outside temperatur outs
air flow [m3h-1]air flow [m3h-1]
air flow [m3h-1]air flow [m3h-1] length (m)
97
75
70
80
98 effectiveness [%]
300
0,1
95
effectiveness [%]
350
dry air
effectiveness [%]
400
350 pressure loss [Pa]
pressure loss [Pa]
400
dry air
effectiveness [%]
100
return-air +20 return-air ºC +2 length 400 mmlength 400 m airflow 150 m3airflow 150 m h-1 100 100 100 99
length (m) 0,1 0,2 0,30,10,40,20,50,3
0,5
fig. 3 Pressure loss as a function of airflow.
0,4
return-air RH (%) return-air RH (%) 100 80 60 14
0,5
fig. 3.1 Effectiveness as a function of the airflow.
Efficient performance keep the exhaust air above the freezing point, even when the outside air is much colder (see Fig. 5). The annual number of hours that the recuperator will freeze is therefore much lower than the actual number of hours of outdoor freezing temperatures. Manufacturers can also reduce the number of freezing hours even further by adjusting air intake, mass balance and recirculation.
The effectiveness and pressure drop as a function of the airflow is illustrated in Fig. 3/3.1 (Note: this diagram is based on a dry return air temperature of 20 ºC and an mass balance). These values have been confirmed in tests by the Eindhoven University of Technology as well as the Netherlands Organisation for Applied Scientific Research TNO. Please note that there is no direct linear relationship between the supply-air temperature and the outside-air temperature when it comes to effectiveness: In return-air return-air +20 +20 ºC ºC fact, effectiveness will increase length length 400 400 mm mm even further under conditions of dry airflow dry air air airflow 150 150 m m33hh-1-1 high indoor relative humidity, with 100 100 100 100 a potential of reaching up to 98% 99 99 thermal effectiveness (see Fig. 4). At 80 80 98 98 extreme condensation, the pressure 97 drop in the return air may double. 97 60 60 The overall result is a very small 96 96 difference in temperature between 95 95 40 40 the supply and return air, leading to 0,5 0,5 94 94 greater indoor comfort and lower basic energy requirements. 0,4 93 0,4 93
20 20
effectiveness [%]
exhaust air temperature [ºC]
15 15
20 20
Reduced freezing
92 92 0,3 0,3
When outside air temperatures are 0,1 0,2 0,1 0,2 very low, freezing may occur at the of150 a recuperator’s duct 00 50 100 200 350 500 50end 100 150 200 250 250 300 300 return-air 350 400 400 450 450 500 if the temperature of the exhaust air air flow flow [m [m33hh-1-1]] air drops below 0 ºC. In the Recair gth (m) ngth (m) Sensitive, heat of 0,1 0,3 0,4 0,1 0,2 0,2 the 0,3 condensation 0,4 0,5 0,5 the moisture in the return air helps
91 91
return-air return-air +20 +20 ºC ºC length length 400 400 mm mm airflow airflow 150 150 m m33hh-1-1
00
10 10 55 00 -5 -5 -10 -10
100 100 80 80 freezing freezing risk risk 60 60 40 40 20 20
-15 -15
00
-20 -20
90 90 -20 -20 -15 -15 -10 -10 -5 -5
00
55
10 10 15 15 20 20
outside outside temperature temperature [ºC] [ºC] return-air return-air RH RH (%) (%)
100 100 80 80 60 60 40 40 20 20
fig. 4 Influence on effectiveness due to condensation heat.
-20 -20 -15 -15 -10 -10 -5 -5
00
55
10 10 15 15 20 20
outside outside temperature temperature [ºC] [ºC] 00
return-air return-air RH RH (%) (%)
100 100 80 80 60 60 40 40 20 20
00
fig. 5 Exhaust air temperature as a function of the outside temperature.
WARM exhaust-air
supply-air
outside-air
return-air
return-air
outside-air exhaust-air (flow direction downwards)
supply-air (flow direction downwards)
COLD
fig. 6
Easy, efficient mounting
The Recair Sensitive has flat sides, side-profiles and flanges around the inlet- and outlet-air connections that allow easy and airtight WARM integration into the heat recovery unit. For optimum drainage of condensed moisture from the heat exchanger, the exchange channels Abluft Zuluft should be positioned horizontally or vertically, and the flow direction downwards (see Fig. 6). Außenluft
Rückluft
Directions for storage, assembly and use 1 Avoid any exposure to direct or indirect UV light, e.g. sunlight. 2 Recair heat exchangers are made of Polystyrene. Polystyrene is not known for its resistance against chemicals, avoid explicit contact of chemicals with the Recair heat exchanger. 3 Operating temperatures: Recair Sensitive air to air heat exchangers may be exposed to temperatures between -20 and +50 ºC. 4 Heat exchangers may only be removed from the apparatus by pulling the plastic strip running over the heat exchanger. 5 Exhaust and fresh air should be filtered at G4 class to keep the exchanger interior clean from pollution.
6 No cleaning with fluids (including water); only careful dust removal from air intake surfaces with a household vacuum cleaner. 7 Recair Sensitive heat exchangers can reveal internal leakage up to 25 litres of air at a pressure of 100 Pa. Under certain conditions this leakage of air could also result in some leakage of condensation. For this reason, the air flow that loses heat should always be pointed downwards. In this way, the condensation will quickly be removed. 8 Pressure difference between the two flows may not exceed 1000 Pa to avoid irreversable mechanical damage to the heat exchanger.
Rückluft
Recair bv P.O.Box 721 NL-5140 AS Waalwijk
Außenluft
Abluft (Flussrichtung: abwärts)
Zuluft (Flussrichtung: abwärts)
KALT
fax +31 (0)416 348 926 www.recair.com
recair sensitive_RS160v2.08
tel. +31 (0)416 347 110
