The Dryer Facts:
When it comes to dryers, where is the perfect installation with little to no duct length? The reality which contractors and homeowners have to work with is far from perfect. A short dryer duct length is not always possible. This is where Fantech Dryer Boosters can help.
Under prime conditions, residential and commercial clothes dryers should dry clothing in a timely fashion. Problems occur when dryers are connected to long runs of duct work. This is the
reason why most residential dryers are located against outside walls. The exhausted air is vented directly to the outside without complicated ducting to hinder the performance of the dryer.
Many dryer installations do not allow direct venting and the typical residential dryer cannot operate efficiently against the resistance created by the necessary duct work. The results are longer drying times, higher energy usage and costs, and excessive wear and tear on the dryer.

Some common examples are:
-
Some common examples are:
Basements that do not allow direct venting.
-
Central interior located
residential laundry rooms.
-
Apartment complexes with
centrally located laundering areas.
-
Apartment complexes with
individual hook-ups for dryers in each apartment.
TYPICAL FAN PROBLEMS:
- Conventional types of booster fans present
the following.
- Their blades clog with lint
- The blower cannot handle the long runs of
duct any better than the blower in the dryer
- The motor cannot handle the heated air from
the dryer and tends to overload
- How to turn the booster fan on with the dryer

When to boost a dryer.
Typical residential dryers are rated at 160cfm. However, boosting is generally needed in order to maintain a minimum
airflow of 100cfm as duct length increases and bends are introduced in the duct line.
Based on surveying the recommendations from dryer manufacturers, and local building codes in selected areas, dryer boosting is typically required when the duct length exceeds the following:
Maximum duct
length with: |
No bends
25' |
1 bend
20' |
2 bends
15' |
3 bends
10' |
Fantech models DBF 110, DBF 4XL and RVF 4XL are all suitable for most dryer boosting applications. Generally the models listed can be used for maximum duct length of 60 linear feet with a maximum of six elbows using four inch rigid duct. For longer duct runs please contact our technical department for specific recommendations.
Fantech Solutions:
Residential: Fantech DBF 110 Dryer Booster Fan
 
|
Model |
D |
d |
a |
b |
c |
|
FR110 |
9 1/2 |
3 7/8 |
5 1/2 |
7/8 |
7/8 |
FR110: 167 cfm, 78 watts, .72 amps, 4" Duct
The DBF 110 Dryer Booster Inline fan addresses every obstacle. A silent partner for your dryer. The fan compensates for system duct losses and allows the dryer to exhaust warm moist air as the manufacturer intended. The fans can handle up to 60 feet of duct and six elbows. The backward blades allow lint to pass through the fan. The attached fully automatic pressure switch is mindful of your energy use, turning the fan off and on, in ten minute cycles, only while the dryer is running.
Commercial: Fantech DBF 4XL Dryer Booster Fan
 
|
Model |
D |
d |
a |
b |
c |
|
FX4XL |
9 1/2 |
4 |
6 |
7/8 |
7/8 |
DBF FX4XL: 148 cfm, 75 watts, .73 amps, 4" Duct
The DBF 4XL features our FX4XL fan with a housing made from galvanized steel with a powder coat, baked enamel finish suitable for most commercial applications. The fans can handle lengths of duct up to 60 feet and six elbows. The backward inclined blades allow lint to pass through the fan. The attached fully automatic pressure switch is mindful of your energy use, turning the fan off and on, in ten minute cycles, only while the dryer is running.
Residential & Commercial: Exterior Mount RVF 4XL
 
|
Model |
a |
b |
c |
d |
e |
f |
|
RVF4XL |
10 1/4 |
13 |
6 |
1 1/4 |
3 7/8 |
2 3/4 |
RVF4XL: 180 cfm, 92 watts, .84 amps, 4" Duct
The RVF Series exterior mounted fans addresses every situation. The perfect solution for condominiums and apartment complexes where concrete firewalls separate the individual units. Venting of interior dryers can now be accomplished easily with minimal interior disturbance. The unit mounts neatly on the outside wall. The RVF matches the same performance requirements as our inline fans. The enamel finish on the RVF is as enduring as it is attractive. The energy savings of the efficient drying of clothes when combined with our new DB10 pressure switch (mounts near fan) is a winning combination. |