Coil Units in Mattresses | Bedrooms & More Seattle

There is no coil unit that is perfect for everyone. Each person has their own preference. Some prefer the response of mattresses with a bonnell style coil; an hour glass shaped coil that has been around for decades. Still others like mattresses with the solidity and durability of a continuous coil system. The often hyped pocketed coil system is another option that has some real benefits in mattresses too. Here is a little info on what makes each style work and some hints as to which might be best for your next mattresses. Included is an expected budget for each style of coil unit. Above this price range, you should consider a superior support system like latex. Below this price, you may be sacrificing quality.

Pocketed Coil System Continuous Coil System Bonnell Coil System Double Offset Coil
Pocketed Coil System Continuous Coil System Bonnell Coil System Double Offset Coil System
  • - Independent coils wrapped in fabric casing
  • - Broad range of durability
  • - Terrific for pressure point relief
  • - Dampens transfer of motion from sleeping partner
  • - Drawback: Body impressions are very common
  • - Example Mattress: The Discovery by OMC
  • - Many coils connected into a single piece
  • - Durable and Responsive
  • - Each spring draws support from adjacent springs
  • - A less expensive option
  • - Drawback: lateral transfer of motion can disturb partner
  • - Bonnell units come in many gauges and coil counts
  • - Look for a minimum of 500 coils for adults or 312 for children
  • - Coil Gauge 13-16 is common; The lower the gauge the firmer
  • - Lighter gauges can still be durable with higher coil counts
  • - Much less expensive than alternatives
  • - Example Mattress: The Hawthorne by Sound Sleep
  • - More conforming than the Bonnell or Continuous coil systems
  • - Similar in many ways to a Continuous Coil system
  • - Foam comfort layers are more likely to wear than the coil system itself
  • - Drawback: lateral transfer of motion
  • - Example Mattress: The Laurel Firm by Sound Sleep



A Pocketed Coil System is a grouping of independent coils wrapped in a fabric casing and joined together with either glue, fabric or thread. Depending upon the tempering and gauge of the coil, you can expect a broad range of durability for mattresses of this type. As a system, it conforms better to your body than mattresses using other styles of coil. It's terrific for pressure point relief if you are a side sleeper (60% of people are). Mattresses using this coil also dampen the transfer of motion from side to side. Therefore, movement does not disturb sleeping partners as much. The down side of this style of coil is that it is less durable for someone that is above average weight. More wear and tear is put on the coils where you are the heaviest, and therefore the foam directly below you. Body impressions are very common with this style of mattress, especially when the product is not on a solid foundation. Being able to vary the coils that you sleep on will maximize the life of this support system.

Budget $799-1599 for a Queen Set.



Continuous Coil units systems are durable and responsive. They consist of many coils that are literally one piece of connected metal and give firm support to mattresses for any size person. By keeping each coil connected, every spring is able to draw support from the adjacent coils and combine comfort with durability. A medium gauge coil is often used to allow for gentle give while maintaining longevity. One drawback is the lateral transfer of motion in mattresses using this coil. This is addressed somewhat through running the strands of coils from head to toe rather than side to side. If you need firm support, but want to avoid the transfer of motion completely, look at latex mattresses. That said, the continuous coil system is a good lower cost alternative.

Budget $699-1399 for a Queen Set.



Bonnell Coil units are made in many gauge, coil counts, and levels of durability. Here are some tips for finding long lasting mattresses of this type. Consider the coil count. In a full size look for a minimum of 500 coils for an adult unless you have a very heavy coil ; 13 or less. A coil count of 312 is great for kids and will be durable in most gauges. Do not buy these tpes of mattresses if they have less than that as you'll end up replacing it sooner than wished. Gauges of 13-16 are common. The lower the number, the heavier the coil and firmer the support. Lighter gauges can still be durable, but you need very high coil counts. Transfer of motion is also an issue in mattresses this style of coil, but it is much less expensive than the alternatives.

Budget $449-899 for a Queen Set.



Double Offset Coil units are slightly more conforming than the bonnell and continuous coils and are essentially the same in function. This system is relatively equal in durability and comfort to the continuous coil system. The most likely portion of these mattresses to fail is the foam on top, not the coils themselves. Coil count rules still apply here, but you can expect a nice firm support and if it is flippable, it is a durable product. As with all coil mattresses, two sides are better than one.

Budget $699-1299 for a Queen Set.

Bear in mind that the suggested budgets are merely a guide and that more and less expensive options will be out there. If you choose to spend less, you will end up with a bed that won't last you ten years or more. Just because something is on sale does not make it a bargain!


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Spring versus Foam Mattresses - by Jeff Garfield