Posts Tagged "hydraulic elevator"

23Jun

Advantages of (Machine Room-less) MRL Elevators

by Andrew @ Uppercut

This article is not referring to passenger elevators and is intended to discuss the advantages of MRL Elevators in a residential or commercial accessibility lift setting. A machine room-less elevator or an MRL Elevator is a device that typically houses the drive mechanism at the top of the hoistway. By doing this the need for a machine room is eliminated, as the entire device is contained within the elevator footprint.MRL elevator

Units that require a machine room( like most hydraulic drives) will also require the electrical and hydraulic hoses to run through a wall from the machine room to the elevator hoistway. In cases where the machine room is not adjacent to the elevator, a remote machine room will be required.  This can be costly and create logistical problems with the running of hydraulic hose through the floor, ceiling or in the walls. It also poses several maintenance concerns; What if a hose ran through a ceiling for instance and it starts to leak? Will it be possible to do a scheduled hose replacement? What type of ongoing costs should you expect in this application? This is a definite advantage of an MRL, having the entire elevator in one contained space.

The second advantage is quite simple; with an MRL elevator, you do not have to allocate the additional space to house the drive mechanism. Depending on the drive system and whether the installation is residential or commercial (B-355),  a machine room could require anywhere from 12  to 20 square feet.  This is space that could be used for storage, a larger elevator car, or a revenue opportunity (like a couple of extra tables in a restaurant).

Finally look at all the costs associated with constructing that machine room. If you think about it,  its equivalent to the cost of half the elevator hoistway  (2 stop). On top of the basic room construction, you will need to provide lighting, possible drains, sump pumps or oil separators, additional sprinkler/smoke detectors, and an additional door (fire rated in a public application).  These costs can add up quickly, and should be considered when calculating the overall cost of the elevator.

To recap MRL Elevator units will:

  • Save you money when it comes to maintenance
  • Require less space
  • Reduce the initial cost of construction

For more information on Commercial MRL Elevators click here For more information on Residential MRL Elevators click here

26May

Choosing a drive mechanism for your elevator

by Andrew @ Uppercut

While many of our clients seem to spend a lot of time selecting elevator car finishes and aesthetic options , very little time appears to be allocated to discussing the drive mechanism. I can’t really blame them; after all talking about what moves that fancy box you just designed can seem  quite boring.  We however, feel it is important for our clients to get as much information as possible, especially when it concerns such an important aspect like the drive of your elevator.

In this blog I will be discussing the strengths and weakness of the following drive mechanisms.

  • Hydraulic
  • Traction Counter Weight

Hydraulic

This system utilizes a pump motor and oil reservoir, to force hydraulic fluid through a hose to a cylinder. The pump motor and reservoir are usually located in a separate machine room. If you areHydraulic Drive unable to provide a  borehole at the bottom of the pit you can use a roped hydraulic system.

Strengths

  1. Price point for the equipment will be in the mid-range when comparing other drives
  2. Machine room is easily accessible for servicing
  3. Manual lowering is inside the machine room
  4. Smooth ride and landing function providing the valve settings are adjusted correctly
  5. Usually, incorporates battery lowering in  the standard product offering
  6. Many manufacturers to choose from

 

Weaknesses

  1. A machine room will be required which equates to extra construction costs
  2. Hydraulic fluid temperature can affect performance
  3. Typically a pit of 8″ – 14″ is required
  4. Some jurisdictions may require a pit drain and an oil separator to ensure leaking fluid can’t enter the water table
  5. Power consumption will be 2-3 times higher than a traction counterweight system – Therefore more ongoing costs
  6. Maintenance costs on hydraulic units will be 2- 4 times  higher (over a 10 year period) due to the potential of leaks and issues with valves , gaskets, and the pump.
  7. Variable usage patterns can accelerate fluid degeneration
  8. If hydraulic fluid leaks there is the potential for the smell to permeate throughout the building
  9. Levelling and re-adjusting (anti-creep) issues

Traction Counter Weight

A traction counterweight drive operates the elevator by having  the mass of a series of  weights counter the elevator car and its occupants. If the user selects a command the elevator motor powers a cable (through a sheave) past the balance point and the device travels at a regulate rate in that direction.

   Strengths  

  1. Lower power consumption than hydraulic or winding drum systemsHome elevator
  2. Minimal  maintenance due to simple design with lower repair costs
  3. No machine room required
  4. Minimal 3″ pit required (or no pit at all with a small threshold ramp)
  5. No worry of hydraulic leaks or smells over the life of the elevator
  6. Variable speed drive for soft stop and start
  7. Low standby power
  8. Minimal issues with levelling even with variable capacities

Weaknesses

  1. Typically the equipment cost will be 10% – 15% higher than Hydraulic units (overall cost may be less when you consider construction and maintenance)
  2. Access to the motor is at the top of the hoistway (for the service technician)
  3. Manual lowering crank is accessed from the top landing
  4. Auto car lowering (similar to battery back-up) can be added for an additional cost
  5. Not a lot of manufacturers to choose from in the Alberta marketplace

A PDF summary of this document can be found here ——> Hydraulic vs Traction