Laboratory Design Newsletter - March/April 2018

Case study 1

Rotovaps: It used to be common to see rotovaps out on the lab bench, but over the last 10 years these devices have moved into the fume hood due to the evaporation of solvents. Because rotovaps require space for the instrument as well as work space for other hood-related operations, the hoods tend to be extra deep, eight feet long and use 1,090CFM at 100 fpm. This configuration burns $6,867 in energy (based on 6.30 per CFM) each year.

In this example, the lab user requested four eight-foot hoods. During the initial stages of the design process, it was discovered that the real reason for the large hoods was the lab user planned to place a rotovap in each hood. Two options, including energy costs, were presented to the user groups (see Table 1).

TABLE 1

Working with all project stakeholders, a design solution of four ventilated enclosures with four smaller hoods was delivered. This saved the lab user 840cfm and $5,040 per year in energy costs, provided a safe work environment (including dedicated hood space) and lowered the operating costs of the lab space. An additional solution of a reduced face velocity on the ventilated enclosures in both occupied and unoccupied modes was presented; but due to the high toxicity of compounds, the health and safety group advised staying in a constant volume operating mode under all conditions.

Case study 2

Biochemistry Lab: This example demonstrates an approach for larger, more complicated labs, such as a 4,000 sf biochemistry lab that works with toxic compounds and a fixed quantity of HEPA filtered exhaust. The users’ initial request had 22 capture devices, including 16 six-foot fume hoods. The existing exhaust system was designed to support a one fume hood per lab module ( 11’ 6” wide by 26’ lab zone).

Using the same inclusive design process, all
the key stakeholders were involved, including
the user group, facilities, health and safety
and design teams. The health and safety
team and an outside organization conducted
an in-depth risk analysis to evaluate all the
products used and processes performed in
the lab. They provided a report which band-
ed all the processes and identified where an
enclosure would be required and the type of
enclosure that should be used. An example
of the evaluation table used to determine risk
can be found in Table 2.

TABLE 2

This report was used to recommend exhaust options. The initial request of 16 fume hoods was reduced to four, combined with two glove boxes, three equipment connections and 16 ventilated enclosures. The user group was provided with four more enclosures and the CFM usage was reduced by 5,145 cfm to deliver an energy savings of $6,760.97 per year (see Table 3).

TABLE 3

By working with all the stakeholders, a safe solution for the researchers was developed. At the end of the process the project-ed energy savings when compared to variable volume fume hood was minor, but the maximum total exhaust was within existing fan and filter limitations. This solution included developing standard operating procedures (SOPs) for each process in the lab prior to the construction of the lab, thereby reducing operational costs.

SELECTION PROCESS

The best practices for lab design
include the process of identifying the
right capture device in the initial pro-
gramming phase. Here is a
three-step process to help
determine the right device for
a lab:

1. Involve all the stakeholders and an industrial hygienist.

2. Describe the hazardous
procedures using the primary
characteristics to quantify
these procedures including:
variable exhaust air strategies (not
occupied in front of containment device,
process not active or standby with con-
tainment device, sash or containment
device door closed).

3. Select the best device and air management strategy for the task based on the information gathered.

Once there is an understanding of what device is necessary, it’s time to review proper installation and testing of the selected device to validate that it is performing as described in the specifications. After ASHRAE/ANSI 110 testing is completed, it is important to train each person who uses the capture devices to ensure the devices will operate as designed. While safety is the most important goal of the containment device, it is critical for users to be are trained to understand how a simple procedure, such as closing a sash or door opening, even when the device is not in use, will save energy and possibly provide additional operational funds for new research.

Type -Size
CFM
Energy
Option 1 4 4360 $27,467.70

Option 2 4 4 3520 $22,175.76

Savings: 840 $5,291.94

Type -Size
CFM
Energy
Cost FH-72 RVE VE-36 VE-48 VE-60 VE-72 GB-35 GB-72 Ex-LYO Ex-utl Ex-ms
Option1 16 4 0 0 0 0 1 1 1 1 1 14,930$68,405.79
Option2 4 4 3 2 5 6 1 1 1 1 1 9,785 $61,644.82
Savings: 5,145 $6,760.97
Ref
No.