Different laboratories with HVAC implications, Part 1
Jeremy Barrette walks through several types of laboratories and the HVAC considerations for them
- Laboratories are an important part of controlling conditions to conduct different scientific experiments or research.
- Depending on the experience or research, different types of laboratories may be needed and will have different HVAC needs.
Labs and research facilities house sensitive equipment and must maintain very rigid standards. Heating, ventilation and air conditioning systems in particular require careful planning and design. Most labs require the HVAC system to be fully exhausted, requiring high levels of outside air.
HVAC can look different, depending on the setting that it is in. First, Jeremy Barrette, principal at Affiliated Engineers Inc., walks us through different types of laboratories and the different HVAC considerations for those instances in this partial transcript from the Aug. 11, 2022, webcast “HVAC: Labs and research facilities.” This has been edited for clarity.
Jeremy Barrette: A laboratory is a facility that provides controlled conditions in which scientific or technological research experiments measurement may be performed or teaching of various sciences is provided. However, sometimes when we’re looking at a project, there may be something that’s called a laboratory, which may not actually be one. For instance, I’ve seen learning laboratories applied as a term in different projects, but it actually just ends up being a classroom.
Before we get into design specifics and codes, we want to do a high-level review of different types of laboratories and what their requirements may be. This is not an exhaustive list, and certainly laboratory types generally fall in more than one category. These days, it’s rare that there is only one type.
Computational laboratories are for data driven research or what you might hear referred to as a dry laboratory. They may range from anything from an open office, to a high-end computing farm with data centers. They may be co-located in other laboratory space, but one thing that we would consider here is there is a need for a 100% exhaust, if it’s more office space, that may not be a requirement. Generally, we’re looking at the cooling capacity for the equipment in the space.
Chemical laboratories are spaces where different hazardous, toxic, flammable caustic liquids, compounds and gasses are used for research. These typically require chemical fume hoods or other exhaust devices such as bench-top, snorkels, ventilated storage cabinets or gas cylinder cabinets. These are typically a 100% exhausted space, especially if we are dealing with fume hood in the laboratories. Our design consideration is for personnel protection, in which the fume hood is that first wave of defense, the exhaust for those devices, and then the associated makeup air to those exhaust. Then, dealing with the exhaust needs of those storage, whether it be chemical, flammable storage cabinets or hazardous gas cylinder cabinets.
Biological laboratories are more biology driven research, where we’re working with different infectious diseases, either cell or tissue culture, protein samples, physical specimen samples, things of that nature, these spaces are usually outfitted with bio safety cabinets or laminar flow tables. The design conditions for these can vary greatly because those bio-safety cabinets can be purely recirculated within the space, and then we’re just looking at the heat rejection. They could be 100% exhausted or a blend of the two. However, the rooms themselves typically are 100% exhausted.
Then, we’re looking at low air velocities and making sure our containment of those cabinets is correct. Depending on what the research is working with, we may also have HEPA filtration in the exhaust stream — the bag out type of filtration. The considerations for protection of the personnel from what they’re working with, protection of the samples from contamination, and again, that laminar low velocity airflow to get the proper containment in the cabinets.
Radiological laboratories are spaces that are working with radiological or radioactive materials or processes that are generating radiation. These spaces may have a combination of fume hoods and glove boxes. It could be bio-safety cabinets, linear accelerators and things of that nature. We have to look at the exhaust stream here and see if there is a need to have special treatment and filtration again, because if there are radioactive materials that are being worked with. These spaces are generally 100% exhausted.
We’re working with personnel protection, not only the ones within the space, but also personnel outside of that specific room. There may be shielding in the walls, floors and ceilings involved. The proper storage and disposal of those radioactive materials is important too.
Optical laboratories are where different imaging, spectroscopy, microscopes or different research involving lasers, may be performed. Typically, clean, stable airflow locations are optimal with low velocity airflows, temperature and humidity stability. To do that, a lot of times we’re pushing our air changes up, recirculating some of that air — although we may still be partially exhausting these spaces. The design considerations here are for stable conditions and low velocity airflow. There can also be a pretty high sensible heat load from all of the equipment in this space that needs to be considered as well.
Engineering laboratories is a broad category. Different spaces for manufacturing and testing, machining, electronics, nanotechnology, robotics and energy studies can fall into this category. These spaces can vary from very shop-like, like a machining room or welding space, to clean rooms of varying levels, to high bay kind of warehouse shop spaces.
Animal laboratories are where either behavioral or medical research is occurring. These vary from holding spaces like the compact cage racks you see there in those images to surgery spaces, and the surrounding support spaces for cage cleaning, bedding and feeding. These spaces may also have a bio-containment requirement. They may be BSL-2 or BSL-3. So, there can be cascading pressurization of the spaces. These are 100% exhausted spaces.
In some cases, the animal holding devices are directly connected to exhaust or they may recirculate within the room. They can also have fume hoods and bio-safety cabinets in these spaces. The spaces are designed with the first consideration is for the ethical care and comfort of the animals, which generally involves high air change rates for odor removal, and temperature and humidity control.
Clinical laboratories are where human patient samples are analyzed for medical diagnoses. These spaces vary greatly and have fume hoods, bio-safety cabinets, grossing stations and different analyzing equipment. There can be a lot of different space needs; biohazard, bio-containment, chemical exhaust in a lot of spaces that have high equipment heat loads.
These spaces are primarily designed for the protection of the samples to not get cross-contamination, as well as for protection of the staff working on those samples. In some cases, there may be dealing with infectious samples as well.