Soundproof or open-frame generator: size, weight and noise

A soundproof generator sits in a canopy that reduces noise and protects it from the weather. It is larger and heavier. An open-frame generator is more compact and lighter but must be installed under a shelter or in a ventilated room. According to our data sheets, a 100 kVA Perkins-engine set measures 275 × 110 × 142 cm and weighs 1,920 kg as a soundproof set. The open-frame version measures 210 × 76 × 140 cm and weighs 1,100 kg.

Soundproof or open frame: what is the difference?

The difference is the canopy. Each data sheet describes a single engine and a single alternator for both versions. Our entire Perkins-engine range comes in a soundproof version and an open-frame version.

A soundproof set:

• sits inside a canopy that reduces noise;
• is protected from rain and dust by that canopy;
• can be installed outdoors;
• is larger and heavier.

An open-frame set:

• is mounted on a base frame with no canopy;
• is more compact and lighter;
• must be installed under a shelter or in a ventilated room;
• gives direct access to the engine.

What are the sizes and weights of each version?

For the same rating, the soundproof version is always heavier. At 100 kVA it weighs 1,920 kg, compared with 1,100 kg for the open-frame version. The table comes from the data sheets of our Perkins-engine diesel generators.

“Not stated”: not given on the data sheet (external tank). The tank can be smaller or larger depending on the version: at 13 kVA it holds 45 L soundproof and 50 L open frame. So check the runtime on the data sheet of the model you choose.

Two example data sheets: the 20 kVA set with a Perkins 404A-22G1 engine and the 100 kVA set with a Perkins 1104C-44TAG2 engine. Weight also matters for transport: see our guide to delivering a generator to the provinces.

How much noise do our Perkins-engine generators make?

The data sheets of our Perkins-engine sets give a single sound level per model, with its measurement conditions. It ranges from 75 dBA for the 13 to 100 kVA sets to 85 dBA for the largest.

To compare two generators, make sure their levels were measured under the same conditions.

A soundproof canopy reduces the noise heard around the set. An open-frame set must be placed so that its noise and exhaust fumes are kept away from people.

Where should each version be installed?

A soundproof set suits outdoor sites close to buildings: homes, offices, shops. It still needs a flat, stable base and free airflow.

An open-frame set suits a plant room or a shelter. The room must be ventilated and the exhaust must discharge outdoors. Location, ventilation and connection rules are in our guide to installing a generator safely.

What about small air-cooled generators?

Small air-cooled sets also come in both versions in our range.

• The Bison and Brux silent diesel generators range from 5 to 15 kVA. The Bison BS7500DSE, for example, measures 95 × 57 × 85 cm and weighs 151 kg.
• The Brux open-frame diesel generators are the 6.25 kVA BX7000DE and the 9.4 kVA Brux BX11000DE.

The choice between air and water cooling is explained in our guide to air-cooled or water-cooled generators.

Frequently asked questions

Can a soundproof generator stay outdoors?

Yes. The canopy protects it from the weather. It still needs a flat, stable base and free airflow around it.

Can you choose either version at any rating?

Yes for our Perkins-engine range, from 13 to 2,000 kVA: each data sheet gives both versions. Say which one you want in your quote request.

Sources: manufacturers' data sheets (Perkins engines, Bison and Brux generators).