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Meet Featured Expert Dr. Nadia Sabeh

Dr. Nadia Sabeh is President and Founder of Dr. Greenhouse, Inc., an agricultural and mechanical engineering firm located in Sacramento, CA that specializes in the design of HVAC systems for indoor plant environments. She is considered the subject matter expert in the field of controlled environment agriculture (CEA).

In this in-depth interview, Dr. Sabeh spoke with us about her road to CEA, what she wishes growers knew about HVAC, and what she sees holding the industry back. You can learn more about Dr. Greenhouse at

When did you first come to be involved in CEA? Did you have any type of background in farming?

Twenty five years ago, after I finished my undergrad at UC Davis in biosystems engineering, I had the opportunity to do an internship at a mushroom farm in Southern Idaho. The farmer was looking for grad students to do field research in order to help him improve production. I wasn’t a grad student, but the universe conspired to send me to Idaho and introduce me to this world for the first time. I lived in a 20-foot trailer on the side of a mushroom farm, and I dove into the world of greenhouses and climate control. The farm was in a semi-arid climate, but mushrooms crave moisture. We were doing everything we could to add humidity.

I absolutely fell in love with mushroom production, greenhouses, and farming in general. I knew what I wanted to do: Help farmers control their environment.

I went back to school and was completely focused on CEA. I got my masters at Kent State and focused on commercial mushroom production, these were kind of the first vertical farms, growing in stacks. Just like our current vertical farms, they had air distribution issues. I really cut my teeth in the industry trying to solve those types of problems, trying to get air moving effectively. I eventually branched out to different crops, studying greenhouse cooling, evaporative cooling, ventilation for tomato production, and more.

So I guess you could say that CEA found me, I wasn’t really looking for it. I was interested in farming and agriculture, but CEA in particular grabbed me.

How exactly does Dr. Greenhouse help potential growers execute their plans for a CEA project?

We specialize in HVAC and climate management for growers and owner operators. We’re very plant focused, so for us to help growers, we need to start by understanding how they’ll be cultivated. What’s your crop cycle and harvest schedule? Are you growing for 18 days? Or 30? Or 60? Every crop is different, and different markets want different things. What are you even growing in the first place? Small plants don’t transpire a lot, but big plants put out a lot of moisture. And while a batch cycle has a lot of fluctuation, a perpetual cycle has a more stable average.

People want to design turnkey facilities/solutions that can be airdropped into any location, but these factors make a difference. And the external climate still has a big impact. We need all the information I shared above, and so much more, so that we can do our calculations correctly. A one size-fits all solution is not going to lead to optimal results.

Here’s another example. In addition to all the particularities of crops and climate, and of facility type, there’s the question of how much control a grower desires. Some want really tight control – plus or minus a single degree or two. Other feel comfortable with a wider margin. To maintain tight control, you need a really advanced and nimble HVAC system, but that can be more expensive. We don’t expect growers to know the ins and outs of HVAC, or what combination of components is necessary to maximise plant growth, but we love to help them learn, and to design those systems ourselves

What are some of the most common misconceptions that first time clients bring to a CEA project?

The most common misconception I see is that controlling the environment is easy and cheap. People understand the principle of photosynthesis and are reasonably attracted by promises of artificial lighting that can replicate the power of the sun. People understand how important water and nutrients are, and know they need to pay to get their plants the best of both.  But when it comes to the climate, it’s just so easy to take for granted.

It makes sense, right? We see that plants in general can thrive in so many different environments. So the idea that controlling the growing environment can actually be a significant line item doesn’t always immediately resonate. In fact, when you look at a successful operation… we’re doing our job if you don’t notice the HVAC system. But we almost do ourselves a disservice, because people don’t realize the complexity and necessity.

Now, to be clear, I actually see this dynamic slowly changing, but often, HVAC is more of an afterthought. Something that only occurs to people when there’s not much space, budget, or time left. Sometimes we’re at the bottom of the totem pole, and then we see people struggling with complications from not sufficiently prioritizing climate control.


CEA is undeniably a growing field, but faces some big challenges. What do you see as the biggest challenges for the industry to overcome? Do you see any solutions to these challenges?

The challenges I see all relate to the effectiveness of CEA technology, but more importantly, they come from the fact that we’re not able to accurately quantify the effectiveness of current technologies.

What I mean is, I could just say “we need more research dollars to develop better tech.” But there’s a bigger picture here too. Across the industry, we are struggling to advance because of a lack of transparency around how our current tools are actually working.

The word transparency has been thrown around a lot in the last several months, especially following some of the high-profile closures in the vertical world. There have been so many claims about how much less energy or water vertical farms can use. But the problem is there’s no data to back the claims up. If there is, it stays with the company or the organization. It’s not declared or publicized in a meaningful way. So it’s hard to know if vertical really is living up to its claims. If the claims prove to be false, it can stain the rep of the entire industry. But it’s also really hard to set benchmarks or baselines.


I should clarify too, that I’m not just talking about transparency around impressive yield, or sales, or quality. I think if we want to improve as an industry, we need to share more minute data that actually relates to operational management, like kilowatt hours of energy consumed per pound of tomatoes produced.

We all want to get something better, but people are trying to set a future standard, and we don’t necessarily know what our current standards are.

More and more people are looking to CEA as both a viable business opportunity, and a way to grow clean, sustainable food for their communities.

What’s the biggest piece of advice you’d give to someone just starting out?


Great question, this really is related to what I was just saying: Measure everything.

Measure the use of your resources from the beginning, and submeter the usage. For example, let me talk about energy. Rather than getting a utility bill that measures your whole operation or your whole greenhouse. I want to go further. What’s the energy used just for the lights, and for the fans, and how about the pumps?

We have several reports circulating which claim that CEA uses “X amount of energy.” But they’re just models. Back to my transparency plea, there’s not good data to validate or refute those reports.

It’s definitely a challenge to meter some components, but having a good idea of how your energy use breaks down can help identify what your biggest abusers are, and where your biggest opportunities are to improve efficiency. If people thought about this ahead of time, you can improve efficiency and even detect equipment failure earlier. Having the power to understand your resource utilization can help you negotiate utility prices, consumable prices (like fertilizer), and can help you track inventory more closely.

If you’re able to reduce one thing in the equation, a lot of times everything else comes down. Reduce lighting intensity and, you can reduce HVAC intensity needed to cool. And then you don’t need as much water; you don’t need as many nutrients.

There’s limits, and every crop has its needs, so don’t reduce for the sake of reducing, but you need data to optimize. Document, document, document. Record, record, record. Apply the scientific method. Try, record what happens, and then repeat if you like the results.

How do you see AmHydro and Dr Greenhouse bringing our combined experience to make our industry (and individual projects) a success?

Maybe you’d be surprised to hear me say I don’t know a lot about growing systems. Honestly! We have a couple in our offices where we grow different crops. We try to build these to gain our own experience, but it’s not our area of expertise. Our area of expertise is managing the air around the plants.

What I love about AmHydro is that they have real experience with greenhouses. They’re not just selling products, I see them as kindred spirits to Dr. Greenhouse. I use consulting as a way to educate and train our clients, and I see that AmHydro shares the same desire; not to just sell someone a fish.

They’re there for the life of the system, training them how to have the same expertise and be successful.

Joe Swartz, especially, is just really nice. He cares so much about the industry; about the big picture. We’re both in it for the long haul. Hopefully people see us as a stable force they can rely on for the support they need.

Oh, and another thing. Although AmHydro is greenhouse focused, the company doesn’t act like they’re the only solution. They see the opportunity and challenges associated with vertical and indoor, and they’re here to support the industry as a whole, not just one methodology.

Finally, tell us about your podcast! As well as any other ways that people can learn more about you and Dr. Greenhouse.

Our podcast is called “The Dr. Is In”. You can get it on Spotify, iTunes; everywhere.
We actually had Joe Swartz on as a guest last year! I have two types of episodes. First, interviews. Last year I spent a lot of time interviewing growers. In our “What Plants Crave” series, we covered all different crops.

This year the interviews expanded to technology providers, like tech people and suppliers; talking about the challenges and innovations of various technologies. The second type of episode is “Lessons”. In these, I talk about various topics on which I myself have expertise. We just finished a three part greenhouse series, covering cooling, efficiency, and technologies.

People should definitely check out the podcast, but we also have a ton of information and resources available at our website,


Thank you, Dr. Sabeh!

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