Jamie Kono:
Hi, everyone. Welcome to the ASHRAE Journal podcast. My name is Jamie. We're going to be talking today about commercial building efficiency upgrades and why you shouldn't forget the windows. First off, I've got a couple folks with me here. We'll introduce ourselves and maybe share why we care about windows and commercial efficiency upgrades and maybe why you all should care about it too. Laura, can you start us off?
Laura Van Rietema:
Yeah, for sure. So I'm Laura Van Rietema. I've been working in the industry for about seven years. The past four years have been at Taylor Engineers. When I started in the industry, I was at a full service firm that did mostly K through 12 schools, and I got really passionate about the built environment and how it can impact people. When I moved to California, partly for personal reasons, but partly because California's kind of on the cutting edge of sustainability design and I got with Taylor, then I could really start getting dialed in on how to make all buildings as efficient as possible, and that's new buildings and existing buildings. Today we're talking about getting an existing building to be fully electric and decarbonizing it. So that's really exciting to me and I think it's really exciting for just the world because it gives us a ton of opportunity.
Robert, do you want to go next?
Robert Hart:
Sure. Yeah. So, Robert Hart, Lawrence Berkeley National Lab. I've been there just over 15 years now. So I guess what got me into this. I'm really interested in heat transfer and fluid dynamics. That is what I studied. And I actually started in HVAC as well, didn't like it quite as much as Laura did. Kind of moved and wanted to get more into the design side of things, and then just kind fell into the research side and started at LBNL as kind of a be there for six months temporarily and for 15 years later, I'm loving it. So Jamie, I guess you didn't give yourself intro.
Jamie Kono:
Awesome. I'm Jamie Kono. I am a research engineer at Pacific Northwest National Lab, although I am talking more as my own self today. My background is in energy auditing and a little bit of buildings, residential and commercial buildings research along the way, and also have been looking up puns for the past month in preparation for this podcast. So you're all warned, you can... Well, you shouldn't stop it now, but you could stop the podcast now if—
Laura Van Rietema:
Get ready world.
Jamie Kono:
Yeah, and I used to work at an energy auditing company that's been collaborating with Laura's company on helping out this building we're going to dig into more later. Before we get into that specific example of essentially how a large commercial office building achieved its performance goals by including window upgrades, we're going to talk a little bit about the commercial building market and Robert, could you talk a little bit about the commercial market? How many buildings are there? How big is this market? How big of an impact could window upgrades make in the US?
Robert Hart:
Yeah, I have all sorts of numbers here in front of me, so I'll spit out a few. So it's about six million commercial buildings in the US or about a hundred billion square feet. 40% of those are about two and a half million are still single pane. So we have a lot. The energy savings potential of that is billions annually. So there's a huge kind of opportunity I think in the retrofit space. But talking even new construction, I know that's not the focus here, but something to think about, windows are about 12% of a typical commercial building of the envelope area, but they account, just a code level window, accounts for about 50% of the heat lost through the envelope. So that's using kind of the standard windows of today. So even we have a huge issue with the existing buildings and on the retrofit side, but even on new buildings, windows still have a long way to go.
Jamie Kono:
Would you say that this is a large window of opportunity for the commercial building sector?
Robert Hart:
Do we have a little ticker, we have a little ticker, like a counter for the window puns?
Jamie Kono:
Yeah, yeah. Or just a boo-track to come on. Well, yeah, so bad jokes aside, we're going to be following one building's journey to use window upgrades to achieve its goals. Laura, could you talk a little bit about One Maritime Plaza and about its really far-reaching performance goals?
Laura Van Rietema:
Yeah, for sure. So One Maritime Plaza is a 600,000 square foot high rise that was built in 1967 and it's 25 stories of class A office space. So when we get into the class A office space, the people who are renting, especially in Bay Area, have an expectation of performance, but also sustainability. So the owners of the building started conversations with us at Taylor, not me specifically because it was a little bit before I joined Taylor, but One Maritime started talking to Taylor about how they can electrify the building or just decarbonize slightly as we go. So our study started in 2020, and the question was, can we just do like-for-like replacement to get rid of the steam gas boilers that are on site? In 2020 when it was just a mechanical focused project the answer was no. The building is designed for 180 to 200 degree water, which serves reheat along the perimeter, and at that water temperature, it kind of excludes the heat pump options that can provide about 130 degree water.
So then we had to look at electric boilers, and with only electric boilers, we'd be replacing, what was it, 20,000 kBTU. And the electrical service for an electrical boiler for that size just isn't at the building currently. Instead of doing a replacement for an electric option, we went with condensing boilers so that we can start a reset in the building and run more efficiently. And then the plan was always to come back and reassess more holistically how can the building get to their goal of decarbonizing the building, or if that means electrifying the building. Great. So we did kind of have to throw out the electric boilers just out the window.
Robert Hart:
Ding.
Jamie Kono:
Awesome. Well, so One Maritime Plaza has this goal to reduce its carbon. It looked like electric resistance boilers were not feasible. What was the next step? How did you all approach this?
Laura Van Rietema:
Yeah, so about two years after, we kind of determined that electric boilers weren't an option. Heat pumps weren't an option, so we just replaced with condensing. We got a electrification feasibility study going, which really was a charrette of about, it started with 20 people and they were people who had been involved in the building are involved in the building or just specialists in kind of energy analysis. So Jamie was on the team, but we looked at how can we take this existing building and collectively through mechanical, electrical, architectural design, how can we get to a point that we can move away from gas? So the huge limiting factor here is the perimeter induction units that serve all of that perimeter heat and cooling needs. And that was designed as a constant volume system receiving it while heating 200 degree Fahrenheit water. So that was the biggest hurdle.
How do we change how we serve the perimeter to allow for lower water temperatures and to make sure that the building was still conditioned effectively? Additionally, these perimeter induction units made any sort of step retrofit difficult because they receive all of their air and water from the floor below. So in these existing building retrofits, it's often nice we have a tenant turnover. Then you can start implementing changes that you want but not impact the rest of the building. For this perimeter system specifically, you do impact the people below you, and since it's a constant volume system that's split up into eight air handlers, four serving the upper part, four serving the lower part, as soon as we start playing with that perimeter induction system, the whole building starts getting pretty impacted. So there was a large study about what system mechanically should we move to, and then because we couldn't just do it mechanically, how can we architecturally make that happen?
We also, in addition to all of the other things that I talked about inside the building, comfort and impact, we are limited with what we can put on the roof. So even if we move away from 180 degree water, heat pumps are still providing only about 130 degree water. So if we have a roof, when we have a roof and we want to put a bunch of air to water heat pumps on it, that starts weighing a lot and it can take up a lot of space. So a like for like replacement of the existing boilers would be 20,000 kBTU, which takes up the entire roof and structurally doesn't seem realistic that the building could support it. So we also needed to reduce the heating load so that our structural impact and space taken on the roof can be reduced. So that kind of brings us back to this window retrofit and what Robert was talking about, how most of our losses are through windows. So we started really talking with the architects involved and Jamie to figure out what options we have for a window retrofit.
Jamie Kono:
And I remember at that point when we were doing energy audits for our various clients, we would bring up window film or window insert options as potential upgrades trying to lower the load of buildings. This is a pretty new approach because generally the thought was, "Well, windows aren't going to pencil out. They're a high initial investment for great savings, but not enough to weigh out, to outweigh the cost savings benefit." However, that's changing. That's why we're here and something, something throw out windows.
Anyway, yeah, I guess so combine that with this feasibility study where we're seeing that a big path forward for One Maritime Plaza is to just lower its load. This is kind of the perfect solution we have. We can enable an HVAC upgrade. We can over the long term, save the building a lot of energy, stop them from throwing their savings out the window.
Laura Van Rietema:
There it is.
Jamie Kono:
And just we're seeing really a much more cost-effective solution with all the different changes going on in the building. All right. Hooray windows. This is great. So, Robert, can you talk a little bit about how windows can be impactful more specifically for commercial buildings?
Robert Hart:
Yeah, of course, energy. we just talked about it, right? So reducing load, reducing peak loads, and this can be heating and cooling energy to solving your solar loads, which a lot of the country has a solar load or overheating issues, but also thermal loads. So your kind of U factor side of the equation. So even if it's very hot outside or just very cold, tempering the temperature that's near the window really regaining that square footage that's kind of lost. That becomes uncomfortable or just unusable space, in this case, in this building, there's mechanical equipment there that's needed, but if you can get that to be in more comfortable space and not have that equipment there, you're actually gaining usable square footage in a building, which it makes a huge difference. And I think we talked about here, we haven't really talked about what the solution is, but you mentioned kind of cost or penciling these things out, and most people think of as a replacement window is kind of the solution and replacements are expensive.
There's no way around that really. There's a lot of materials used, there's a lot of labor involved in a full window replacement, and it kind of often puts that out of reach. It's something that when the frames themselves are in good condition, say if it's the metal frames or the frames haven't started rotting and they aren't leaking and things like that, it's not necessarily the best option. There's a lot more things that can be done. Really, that's kind of what we're talking about today. The thing that we also need to think about is that in this case, I think it really is done for energy efficiency, but in a lot of cases it's not. What really drives a retrofit is not the energy efficiency issue, it's something else. So the tenants are uncomfortable, they're having a lot of overheating. You can't maintain the temperature in the space.
They're having glare issues, things like that. And those can often be solved without that full retrofit by, say, applied films or secondary glazing, external shading or internal shading. Maybe they're having condensation problems. So if you live in a very cold climate and you still have those non-thermally broken metal frames, single pane windows, or even some double pane clear windows, you're going to get potentially condensation problems. This is an aesthetic problem, but also a health problem. That can be a liability for the building owners and managers. And so that's something you really want to consider. Again, do you need to do a replacement? There are other options. So secondary glazing, you can do re-glazing with vacuum glazing, very high performance wind glass can go into these frames and get you pretty high performance windows overall. So there's a lot of options. The most important is just to find the one that addresses your issue because that's going to be the one that's kind of the cost-effective solution, is fix the problem that you have with that existing building.
Jamie Kono:
And from talking about how we were looking at window upgrades more in our energy auditing with these lower cost options as well as with increased goals for doing these kind of large HVAC retrofits that will benefit from having lower heating loads. Now we're talking about moving window upgrades down the tree, the fruits lowering on the tree. If we're talking about that metaphor, typically when you approach a building for an energy audit, you are looking at, okay, what are the low cost, no cost measures? Absolutely do those. What are the moderate investment measures? And likely do those. And so we're talking about lighting upgrades, building tune-ups, getting done. Those are kind of no-brainers. But then we move up kind of farther up the tree in our metaphor here of envelope upgrades and HVAC upgrades. These are large investments that don't always pencil out, are often driven instead by capital replacement timelines or other kind of motivating factors.
However, because of these availability of window films and secondary windows, we're seeing that fruit go farther down the tree and it's a lot more cost-effective to do these measures. On top of that, then you have the other conditions that could trigger a window upgrade, such as changing HVAC system or improving tenant comfort, resolving some complaint in the building. And you're now looking at windows as a much more reasonable, much more feasible option for a building, and you don't want to miss out on that potential long-term building savings and improvement to the building in general.
Okay, so we'll bring it back to One Maritime Plaza and its HVAC upgrade. How specifically did One Maritime Plaza look at upgrading the building? You mentioned a whole building approach to solving this problem. How'd you go about that, Laura?
Laura Van Rietema:
Yeah, so the solution that we ultimately landed on is with a window retrofit and more insulation on the envelope, we can extend the internal VAV reheat system to serve all of the heating needs of the building. So that perimeter induction unit currently lives on the exterior wall. It's against uninsulated spandrel. So part of the process is adding insulation there. So we have less envelope losses, adding insulation on the spandrel above the ceiling. But then the biggest saver for all of our savings on reheat was a window retrofit. So that's leaving the single pane glass and inserting a double pane window in that existing frame. So by doing that, and then a few controls retrofits so that our internal reheat systems are operating with a reset, allowing for energy savings there, and also just optimizing control to only have the hot water when the hot water is needed, which actually accounts for a lot of savings.
And in Jamie's metaphor of low hanging fruit control retrofits that just start implementing resets on hot water temperature and airflow to zones. Those are the lowest hanging fruit that I think is a really easy first step, which will allow you to rightsize your boilers. So you start thinking about air to water heat pumps, or even electric boilers. That right sizing is crucial because electrical service to a building is often what prevents fully electrifying a building. So with better envelope performance and those control upgrades, we're able to push our internal system to serve all of the heating load. I know I already said that, but that's the critical part of this design. And then on the cooling side, our windows are helping and they do perform better, but our internal systems are limited because their existing riser sizes.
We are updating duct sizes on the floor, but we wanted to limit any of work that we did inside the riser. So any additional cooling load that the internal system can't pick up will be done with a condenser water loop. So fan coils will be added on that condenser water loop to just provide any sort of extra cooling needs. And the solution led to no major retrofits to the existing systems, and it's just slowly decommissioning the perimeter induction system. So of the 16 air handlers in the building, eight of them are perimeter induction unit like serving, and those eight are slowly just getting less and less floors to cover. And so each time we retrofit a floor and decommission the perimeter induction units, we do have to rebalance those fans for a lower airflow since they are constant volume. But at this point, I think we've done four floors and it's going pretty well, which is exciting.
Jamie Kono:
And I know that this kind of gradual incremental approach, this kind of incremental approach is really helpful to these large commercial office buildings because then you can plan it with tenant turnover, you can plan it with your capital budget, so you're not doing everything all at once.
Laura Van Rietema:
As Jamie pointed out, it is kind of like a step-by-step based off tenant turnover. So our expected completion time is in 20 years, which that is a pretty wild timeline, but the building is committed to doing this, and some tenants are seeing the improvements and they're like, "Well, we'd be okay with you coming into our space and changing this stuff." So maybe it can be done faster, but it is a slow implementation process. And as technology changes, our end design might be different. So if heat pump technology gets a lot better, who knows what we'll end up doing. But the current plan is just move away from the perimeter induction units that need that 180 to 200 and then move to the VAV reheat that can serve the building heating load with about one 30 degree water.
Jamie Kono:
Yeah. Awesome. Let's get more into why window inserts ended up being a clear choice for this.
Laura Van Rietema:
If you missed it, guys, that's a pun. All right.
Jamie Kono:
You all can't see my face, but that's a clear choice. Robert, could you talk a little bit about the window insert process?
Robert Hart:
I think it's more of the low E-choice, but that doesn't sound quite as good, does it?
Jamie Kono:
The low E-choice. Yeah. Okay. We will workshop that. We'll get back to you.
Robert Hart:
So I guess maybe explain what these secondary windows are first for folks that people that aren't aware. I think there's, unfortunately the industry hasn't really settled on the name. I think on the residential side, it's storm windows. That has been a pretty settled upon terminology. But on the commercial side, secondary windows or commercial secondary windows, secondary glazing systems, they are all used interchangeably. They're all pretty much the same product. They're just glazing systems that are added in addition to the existing window or the prime window.
These products are—there's internal versions which go on inside the building. There's external ones that can be attached on the outside. Both those products are on the market. I think that interior are probably the most common on the commercial side, whereas on the residential it's more the exterior storm window is the most common. For commercial, I think that's mainly because especially when you get to taller buildings, it's just the access is so much easier to do that on the room side and instead of having to put up scaffolding or other maybe higher risk hanging from the building and all those things where it can become quite a bit more expensive to do it that way.
And of course for staging when you do interior, it's a lot easier to stage that. So as far as their kind of performance of these products really depends, just like a prime window depends on the glazing used. You can increase, if I may say, if you had a single pane clear window, stick a single pane clear on that, you really do get about the performance of the double pane window. But there's products out there with low E-coatings. There's products with double or even triple pane secondary glazing. So you can get quad pane level performance out of the center of glass, which is quite high. And then you also get a benefit with almost all of these products is that the frame itself is somewhat separated from the base frame, so you get a nice thermal break at the edge of glass as well. So you get a decent performance there.
So the whole overall window performance gets quite a bit better. There's a lot of variety in these products. There's some of them that are permanently installed, they go in there, screw them in place. So all around the perimeter. There's others that are designed to be very easily removable for easy maintenance. If someone needs to go and maybe they want to have clean in between that space once a year, maybe they need access to those windows. There's common windows, they center pivot windows that can turn and so you can clean the outside of it without having to go on a lift on the outside and drop down the building. So if you have that style of window that these products you want to utilize, one that's easily removed can kind of just lift up and out or is hinged that you can open it and access it?
Yeah, there's versions that are made to be utilized with operable windows. So if you go into somewhere that needs, say, egress or just ventilation, some windows are still utilized for ventilation. There are versions of these products that can play friendly with those as well. And of course, shading devices. I mentioned glare earlier. Most of these products, if not all of them, can be utilized with different shading systems with internal ones. So if you have Venetian blinds or roller shades or something like that, there's a way to utilize those as well. And so I think why would you use these products, right? A full retrofit is just simply cost. It can be significantly cheaper to do this than replacement, costs roughly a third in cases, plus or minus a little bit. That makes that pencil outright. You talked about that earlier, a lot easier. Yeah, I mean, we've talked about the range of performance for these.
I think, Laura, you can confirm this, but I think the product that you guys have in this building, it was a single pane window that had a film. Is that right?
Laura Van Rietema:
Yeah, that's the existing condition.
Robert Hart:
And so coming in here, sticking on another single pane product or a double pane, so a double pane low E is going on it. So you're getting of a U factor of around one, which is what you kind of have with a single pane metal frame to U factor around below 0.3, so like 0.28 I think as you have here. And lowering the solar heat gain. So you already had a film on these units, the baseline window, but adding these additional layers, you're getting a lower solar heat gain. So even helping the cooling load as well. And of course all of that helps with comfort. So energy savings and the comfort associated with that. It's huge.
Laura Van Rietema:
So these window retrofits that we're putting in at One Maritime Plaza with rightsizing, we could reduce the amount of heat needed by about half. So the original building had 20,000 kBTU, right sizing and controls retrofits. We got to 8,500 kBTU. But with these secondary windows, we're down to just over 5,000 kBTU, which really allowed us to move forward with our feasibility study in electrification, and then ultimately started us on the actual retrofit process. So these windows were crucial for us, and because we're putting them in for additional savings, and the owner is really pushing for this electrification, the payback is there, but maybe a little less important. So I think running the numbers makes sense for every project. And this one just happened to work well for us.
Jamie Kono:
And I just wanted to kind of highlight, so we're talking about essentially at the start of this project, walking into the boiler plant, looking at 20,000 kBTU of heating potential in the building. And now we're looking at, oh, there's only due to rightsizing, controls upgrades, insulating spandrel glass and secondary windows, we're cutting that essentially down to a quarter of the load previously. So there are four big steam boilers there before, theoretically, this could put you at just one of those steam boilers, and that's converting one of those steam boilers to an electric option is way more feasible and the fits much better on the roof, right?
Laura Van Rietema:
Yes.
Jamie Kono:
And then not to mention that you're getting to remove those perimeter induction units. Think of all the folks that can scoot their desk right up to the window now and they won't be frozen in the wintertime or overheated in the summertime, and they won't have this piece of equipment in between them in the window. Anyway, it's really, it's a pretty neat change.
Robert Hart:
It's San Francisco, they're going to be freezing at all times.
Laura Van Rietema:
Hey, hey. It gets pretty warm in the financial district.
Robert Hart:
That's true.
Laura Van Rietema:
But this removing the perimeter induction units has been a pretty compelling reason to do this whole project because a lot of the tenants in the building have a lot of complaints about those units. They're currently pneumatically controlled, and some of those pneumatic lines have been cut or have leaks, so they're not controlled very well to begin with, and they're loud because you're pushing a lot of fast moving hot or cold air over a coil. So the improvements that these window retrofits and envelope improvements have on the building are, they go way beyond just allowing us to retrofit the building. Comfort will be better, and that's comfort temperature-wise, but also just like in your office noise-wise. The film that we remove from the existing window also got a lot of complaints because it was quite tinted with the window retrofit and the new film that's being used, it's really, it appears to be a clear glass. And so all of the tenants are walking through these renovated spaces and they're seeing that the tint on the windows is gone. And they're like, "How do we get that? We want that." The views from One Maritime Plaza are fabulous. You can see Golden Gate one direction, Bay Bridge another. San Francisco's great, the temperatures really nice all the time.
Jamie Kono:
She's bragging now.
Laura Van Rietema:
I am bragging. I love my city, but the tenants are really pushing to get the window retrofit sooner rather than later, so that's allowing us to start having a ton of energy savings sooner. But they still have the perimeter induction units, so it's moving a little bit faster than we expected, which is awesome. And I think most people in the building are quite happy with it.
There was a story that in one of the floors that got window retrofits without the full retrofit, they had been complaining about smells in the office. And when they went to improve the envelope, they found that there was just kind of a hole that ran up a column. So they were getting hamburger smells from the bar below, just in their office all the time. So this envelope improvement also improved air infiltration. So the benefits are cascading and it's awesome. Definitely recommend looking into window retrofits and just envelope improvements for energy savings.
Jamie Kono:
This isn't just at One Maritime Plaza that we've seen great improvements from window upgrades. Robert, could you share a couple examples?
Robert Hart:
Yeah, I mean, I have lots, maybe, I know we're probably going long here, but I could share one that I think one of my favorites. So this is a project that NEEA or Northwest Energy Efficiency Alliance did. They did a study on, and it's a building in Vancouver, Washington, so just North of Portland, Oregon. And they, I guess probably kind of a similar problem. They had an issue with their meeting their loads. The HVAC system was kind of maxed out. They looked at what are we going to do to solve this problem? I mean, they had tenants basically just leaving the space. They couldn't, you get temperatures in the 90s outside, and it would be in the 90s indoors as well. And so not really a work environment. And they really had no space to increase the HVAC size. So they were looking at solutions, ultimately settled on a similar approach of a secondary glazing system, really reduced those solar loads, right?
So their problem was solar loads, and they came in, replaced this, and actually within a couple months of that full replacement, this was a few years ago, if anyone remembers that, the massive heat dome that they had, they hit temperatures of 115 degrees outside. Previously, again, they would have 90 plus indoor air temperature would be that. And the building manager wrote an email to the NEEA team that every zone in the entire building was at set point hitting 72, no issues. And that the only change was this window retrofit. And so just a massive improvement essentially getting back all of the square footage of this building, which really just couldn't, it was hard to keep tenants in this space if you can't, no one really wants to rent a space that's going to be 90 plus degrees inside. I think that's one of my favorite examples.
Jamie Kono:
That's awesome. I'll also include here at PNNL, we're in Eastern Washington state. We have a couple buildings on campus built in the '70s and have had some window replacements over time, probably as there's been an issue with the window, etc. But we have these lovely floor to ceiling windows where I think the window was installed by literally lowering a sheet of glass into place and then building the frame around it. And so those windows, they provide lovely views, great aesthetics, except that you never really see them because the blinds are always closed because in the summertime it gets incredibly hot and in the wintertime it gets really cold and it's just, well, I don't know how, we could do a different podcast on how you would actually replace one of those windows, but it would be really, really difficult. Not like a pop it out, pop it in type of situation.
But last year we have a internal energy efficiency fund, I guess, that employees of PNNL can submit ideas for efficiency upgrades. And we won the lottery. I say we, but I mean I am benefiting from it. I didn't actually come up with the idea, but so part of this building, the research operations building here on campus got these secondary windows. My understanding is it took one to three hours tops to do these window installs. And that included, they decided to change the window dressings at the same time. So included taking out the old window dressing, putting in the window insert, putting in a new set of blinds all in an hour or a few hours, which was awesome for not disrupting employee activity too much. And then of course, because we're nerdy like that, we installed a bunch of sensors on the windows. And I'm looking at some data here where on a winter morning January of this year, I've got a infrared image of the outside of the window.
So taken from the outside looking in towards the window. So the window with the secondary window insert has a temperature of 20 degrees. The window without the secondary window insert has a temperature of 32 degrees on the outside. So you're getting a lot more heat loss from that window without the secondary insert. Did I put what temperature it was outside? That would be helpful to share, wouldn't it? I don't know. It was cold. It's cold here. I'm from Florida and now I live in Washington, and even San Francisco would be too cold for me. Any who... But those are a couple examples. We've got more, if we went on and on about it. I think we've talked a lot about the other benefits associated with these window upgrades. Is there anything else on your minds that you'd like to highlight relating to One Maritime Plaza comfort improvements?
Robert Hart:
I think one thing I probably haven't mentioned yet is kind of... There's a team at LBNL, actually PNNL involved in this as well, did a study, not just windows, but all kind systems on how we've had a lot of major heat and cold events recently throughout the country. Some of those associated with power outages that become life-threatening scenarios for folks, especially if you're not able to senior housing or things like that where people aren't able to move quickly. And so there's been some recent studies looking at different mechanical systems and envelope upgrades that can help.
How do we make it just extend that time that these spaces are livable so that rescuers can arrive or other things can happen to make sure that the people inside are safe. And a couple of these studies on the heating events and cooling events both showed different window upgrades as potentially adding hours, many hours, and almost days to the time where these spaces can be livable. So if that is, again, kind of gets to the what problem are you trying to solve, if that is one of the things that's a concern for your building, there are many solutions out there to help.
Jamie Kono:
Awesome. Yeah, I mean, I suppose you could say it's the potential to save lives through your windows. I don't know how much that lowers the fruit on your tree, but... Yeah. That's awesome. Robert, did you want to talk about acoustics at all? I forget what this was about.
Robert Hart:
Yeah. I mean, we can talk. I think I mentioned energy efficiency is rarely that driver. We see acoustics as one that's sometimes a driver, especially if you're near an airport or next to a freeway, things like that. We are doing a study with the California Energy Commission over the last few years in multifamily, so not kind of quasi-commercial, I guess we'll call it, but multifamily units where this study was really about the energy efficiency savings. But of course, we looked at some of the acoustics, just took some measurements, but really weren't focused on it, but the feedback from the tenants. So we have about 30 participants or different units in this study, and I think that very few of them noticed their energy savings. It was quite successful in the energy savings part of the study, which was great, but the tenants themselves didn't really notice that that much.
But every single one of them mentioned unprompted about how much nicer the space is that they've been. Some of these people have been in their units for 30 plus years, so they know the space very well. Unprompted say, the thing I like best about this is it's so much quieter inside my space. I enjoy it so much more. And it is kind of amazing that how much the kind of quality of your life can improve just from that reduced noise. So I don't know if that was something of a consideration for the OMB, Laura, because of course, you're in a big city, there's lots of exterior noise that could potentially become an issue. But has any of the tenants or did you guys think about it for that unit?
Laura Van Rietema:
So One Maritime Plaza is a kind of interesting building in San Francisco because it's located kind of centrally on a block and the rest of the block is a plaza. So you do have separation from street already. None of the tenants who have gotten the window retrofits have at least talked to me about the acoustic performance and how it may have changed, but I'm sure that it is better because how could it not be?
Jamie Kono:
Well, and maybe they never heard the street noise before because the perimeter induction units were noisy enough that they canceled it out.
Laura Van Rietema:
So I guess we do get a lot of comments like, "Oh, wow, it's quieter without the induction units going," but the windows were secondary, I guess, there.
Robert Hart:
Yeah, if you have other noises that are louder than the street, they destroy that.
Jamie Kono:
I see what you did there with secondary.
Robert Hart:
I did a pun.
Jamie Kono:
Okay, well, let's wrap up. It's time to shutter up the podcast.
Laura Van Rietema:
Nice.
Jamie Kono:
I have a whole list of puns that I haven't used on you all yet. So now's my opportunity. Just to recap what we've talked about, there are a lot more window upgrade possibilities these days than there used to be. You can upgrade your window without having to do a full replacement, which we know is a large investment. You can use secondary windows, window films, shading, etc. And this really allows window upgrades to be a lot more feasible for projects relating to energy efficiency or to comfort improvements, to resolve some problem that's occurring in the building. It really puts windows as a reasonable thing to consider. And on top of that, now we've got a lot of great examples of how windows can improve the energy consumption, the comfort, both in terms of thermal comfort, sound comfort, hamburger comfort. It's all a lot of potential benefits there that are harder to quantify if we're talking about penciling it out, but definitely a lot more feasible these days. Yeah. So I'd say that window upgrades are not so much of a pain these days. Pane.
Robert Hart:
Nailed it.
Jamie Kono:
Yeah. Any who, with that, thanks so much everyone for listening. Thanks, Robert and Laura for having a fun conversation about windows.
Laura Van Rietema:
Thanks, Jamie.
Robert Hart:
Thanks, Jamie.
Jamie Kono:
And take care everyone.
ASHRAE Journal:
The ASHRAE Journal Podcast team is editor, Drew Champlin; managing editor, Linda Rathke; producer and assistant editor, Allison Hambrick; assistant editor, Mary Sims; associate editor, Tani Palefski; and technical editor, Rebecca Matyasovski.
Copyright ASHRAE. The views expressed in this podcast are those of individuals only, and not of ASHRAE, its sponsors or advertisers. Please refer to ASHRAE.org/podcast for the full disclaimer.