It seems that the pace of technological change is only increasing. Water heating devices of all types are becoming more sophisticated, are being manufactured to more exacting specifications, and are being offered with greater control and connectivity than ever. As appliances and systems become more complex, a higher level of technical know-how is needed to properly install and maintain them.
We sat down with Robert Wiseman, Product Manager for Commercial Boilers at Lochinvar, to discuss just what “state-of-the-art” means for modern boiler technology. Lochinvar was founded in 1939 as the Walter Vallett Company and has long established itself as an industry leader with a special focus on innovation. Wiseman has been working more than 15 years for Lochinvar in various product development and product engineering roles.
CONTRACTOR: So the drive the last few years has been towards greater and greater efficiency. What kind of energy efficiencies can modern boilers deliver?
Wiseman: For the last several years we’ve seen a trend towards condensing boilers, so that gets you into the mid-to-upper 90% range. You still have some retrofit applications that go with the mid-80s. We have some products in that range, your copper-style heat exchanger products. Those are mostly used in retrofit applications.
Now you’re starting to see greater emphasis on the overall system. If all the links in the chain aren’t strong and held together, the overall system [efficiency] suffers. So, all the other components are starting to push their limits too. You’ve got the smart pumps, you’ve got insulation around the pipes. So, the boilers are at the mid 90s, but now with the smarter technology and the communication between all the equipment, all of it really working hand-in-hand. If the boiler has large turndowns you minimize fuel usage in your warmer months when you don’t need the unit running so much; let it talk to a smart pump that will slow down that variable speed, work with the outdoor air, etc. etc. So that’s really what we’re seeing now, especially in new designs, and even with retrofits.
CONTRACTOR: So to deliver the highest efficiency, it can’t just be the boiler, it has to be the entire system, every component working together.
Wiseman: That’s a point I think gets glossed over. You can have a super-efficient boiler (say, a Lochinvar Crest with 96.2% or 96% efficiency) but if it’s put in an application where it’s not going to condense, you’re not going to get your bang for your buck… if the system is not designed to condense there are other boilers that can meet that application. If you want to do a retrofit and want to get the true benefit [of these appliances], you sometimes have to re-design it, reconfigure it. It’s much easier to do it from a blank slate, from the ground up as new construction.
CONTRACTOR: So how are you achieving these efficiencies? What kind of new technology is making this happen?
Wiseman: In the technology world, we’ve really been pushing the turndown [ratio]. The whole theory behind that is, let’s match the heat load. Your old boilers tended to be on/off. If anything they might have been staged—think of it like going up a set of stairs. But they were limited, each stage was either on or off. Now, what we want is a smooth curve… let’s keep it on an even keel, let’s get it on, keep it nice and running, ramp up as we need to and ramp down as the load decreases. That’s where we’re really trending in the past ten years, really pushing that turndown. We went from on-off, to staged combustions, to a 5:1 turndown, now we’re getting up into a 25:1 turndown with these larger boilers.
Now, where things really get interesting, is what we’ve done with the Crest with Hellcat combustion technology. Your thermal efficiency is based on your combustion efficiency. So, thermal is the heat that’s being put into the water, what’s being delivered to it. Your combustion efficiency is what’s coming off the burner. So, in theory, your thermal cannot be larger than your combustion efficiency. That means if the burner is not very efficient, it’s not producing the correct amount of heat to transfer to the water.
With Hellcat combustion technology, we are maintaining the desired O2 throughout the range of the product (and that’s set by the user). But before, in these other boilers, you would set a point (or maybe two points or four points at most), of where you wanted that system to operate. It’s a good system, there’s nothing wrong with it, a definite improvement on the past—but how can we take that to the next level? That’s where we came out and said, hey, let’s come up with these points, but let’s aim for a specific O2. What that has done—based on the data we’ve received from our test sites—is that we’ve decreased that excess air, and when you decrease that excess air it keeps that combustion efficiency up, it keeps the dew point at a suitable point to allow more condensing, and that all leads to better thermal efficiency. Now third-party testing verifies that thermal efficiency.
There’s a lot of smart features going on that really help the user. It has real-time O2 trim. O2 trim is so much more than just aiming for a specific O2… We’re looking at the combustion air temperature, we’re looking at barometric pressure—is it up on a mountain somewhere? Is it down at sea-level? What kind of weather patterns is it seeing? Then we have a commission trim, which is where the user sets the target O2. This takes into account maybe an odd vent set-up. You have an older building, say, and you have to run the vent through some nooks and crannies, the older boiler maybe made some noises when it first started. You can tune that out now by aiming for this optimal 02 with the commission trim, and the unit will run based on where you told it to.
CONTRACTOR: I understand some of the improvements to the Crest were to the envelope—about improving ease of installation and maintenance?
Wiseman: We heard people say, we really like the Crest, but we’d like it if the front door is easier to take on and off, if the side panel was a little bit easier to take on and off. We hope people don’t have to… but we have the reality of, if this thing has to be worked on, let’s make it easier on the maintenance technician… the industrial design was not just to make it look better but to make it more functional in the field.
On the controls side, we’ve got a new 10-inch touchscreen display. Our goal is so that anybody, even someone not versed in boiler technology, they could set this up. We still want skilled technicians working with these, but we had in mind something similar to what you see with a lot of smart phones now, where a kid can pick it up and can immediately call their grandparents. We wanted that same level of intuitiveness on this boiler. We have basically a commissioning Wizard (and we’ve had this on some other products) where it’s a series of simple questions. If you don’t know all the ins and outs of a hydronic heating system, we will walk you through it, to get you set up. And nine times out of ten it’s going to be a great setup. There may be some nuances that a seasoned person may have to come in and adjust, be we want to get you through the basic setup and get this unit up and running.
So it’s going to save that building owner money, not only on the fuel side because of the high efficiency, but less callbacks. If you need hot water, we want you to always have hot water in an optimized manner.