Thread Number: 70752  /  Tag: Other Home Products or Autos
What's with Home Depot's HVAC system in the stores?
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Post# 937240   5/9/2017 at 00:24 (383 days old) by superocd (PNW)        

I'm an HVACR guy by trade but I am stumped as to why every time I walk in to Home Depot and walk around, I am invariably blasted by a jet of air coming from a large ceiling diffuser in its own "box" or plenum (no ducting that I can see). I'm almost positive that there is a high-velocity centrifugal (or axial) fan in each of these.

But why?

If these are just straight fans, wouldn't it have been wiser just to utilize the economizer that is installed on 99% of packaged rooftop units? They already have the ductwork for HVAC in the store. It just seems redundant to have giant, independent fans blow a blast of air into the space.

There would be no way that these are centralized. In fact I heard the motor spool up--as clear as can be--as I was standing right under one. You never really hear the blower motor on a centralized system, whether the system is heating, air conditioning or ventilation.

Post# 937245 , Reply# 1   5/9/2017 at 00:46 (383 days old) by Revvinkevin (Between Mickey Mouse & the Queen Mary (So. Cal.)        

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I'm pretty sure those are not big A/C systems, but rather evaporative coolers, at least here on the West coast. Far less costly to run for large space like a Home Depot sized warehouse space.


Post# 937265 , Reply# 2   5/9/2017 at 02:06 (383 days old) by superocd (PNW)        

Good point about it being an evaporative cooler. I'm near the coast, though...I'm wondering why they'd implement one with our humidity levels? A straight intake fan setup (or just running the economizer) would suffice. Introducing moisture into the conditioned space might cause some problems around here.

I knew that it wasn't an AC system because I've never seen an axial on the evaporator side, let alone for anything else that requires moving large amounts of air over a long distance. A veteran in the field did see a forced air furnace with an odd-looking axial fan (?!?!?!) attached over the heat exchanger, it was ancient though and Was probably the last running example in the US.

Post# 937290 , Reply# 3   5/9/2017 at 05:44 (382 days old) by retro-man (nashua,nh)        

The units here where I live are normal gas heat and electric a/c's. There are numerous one located all over the roof. You can see them as you drive into the yard. Road slopes down to the store so you can see the roof. No chillers here maybe because of the extreme cold weather we get.


Post# 937300 , Reply# 4   5/9/2017 at 07:49 (382 days old) by Yogitunes (New Jersey)        

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if anything, I would ask a commercial HVAC installer for info as to why certain systems are used for some applications...

but you can have that a hundred times asked, why one installer would install or use a system one way, only for another installer criticize as in, 'what the hell were they thinking?'....

many times we see them install, but not THINK!

Post# 937319 , Reply# 5   5/9/2017 at 10:07 (382 days old) by panthera (Rocky Mountains)        
Our local Homeless Despot

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Loses several staff every summer at the start of the 'cooling' season. Which is, apparently, dictated by the tomfool idiots Down South, not by our actual conditions.

The swamp coolers stink - they never get cleaned.

They make the store cold and clammy - and we have under 50F days in JUNE at our altitude.

They drip and drizzle.


I've felt the comfort of mobile homes cooled by the two-stage systems in Arizona, so I know they can be done right. These, however, are a disaster.

Post# 937323 , Reply# 6   5/9/2017 at 10:26 (382 days old) by wayupnorth (On a lake between Bangor and Bar Harbor)        

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Yes, the home office of all these major chains control the temps inside the store. I had a neighbor that worked at Lowes that said they could not regulate the temps in the store, it was all done in the corporate headquarters to what they deemed to be comfortable.

Post# 937329 , Reply# 7   5/9/2017 at 10:38 (382 days old) by GusHerb (Chicago/NWI)        

Homo Depot around here just uses regular RTU's (usually see Aaon). Not much for ductwork, usually just a plenum dropping down from the RTU into a 4 way diffuser aimed towards the floor. And they use ceiling fans for extra circulation.
At the front of the store they have an RTU for the registers/customer service with a diffuser over each station. For the entrance they have some pretty large unit heaters.

Out west I've seen swamp coolers, seems to work ok in the dry areas. I forget how they were heating those places though, probably duct furnaces I feel like. In Arizona they were using regular RTU's.

Lowes pisses me off, they keep it around 76 in the summer which is real stuffy especially while moving around. All the stores used to keep it between 72-74 until around 2009. Now it's hard to go anywhere that's cool enough.

Post# 937330 , Reply# 8   5/9/2017 at 10:38 (382 days old) by duke ()        


The installer would not have a say in the decision as he would certainly be adhering to the mechanical drawings for the building being constructed.There are plenty of mechanical engineering firms submitting their ideas to the idiot upper management of each firm.Pennies sometimes dictate which plan is chosen.Our units in SC stores are truly air conditioned while some have swamp coolers in the semi enclosed garden/plant section.

I have installed the HVAC in many Burger King's in my area which required conditioned air be used for make up air for the broilers and fryers--STUPID-When I objected to B.K. corporate in Florida,I was told to build it their way or no way--Period.

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Post# 937331 , Reply# 9   5/9/2017 at 10:44 (382 days old) by panthera (Rocky Mountains)        
I avoid Lowe's like the plague

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Their corporate position on transgender people is disgusting.

But, even if they were pro-American, their staff is C-L-U-E-L-E-S-S.

I want people I deal with to know MORE than me, not less than a stale cucumber which got thrown behind the dumpster a year ago at the organic grocery store down the street.

Ours will put seedlings out IN THE SNOW because corporate says to - and we get snow at our altitude 12 months out of the year some years. Well, the ones which end in even or odd numbers, mainly.

Post# 937394 , Reply# 10   5/9/2017 at 16:54 (382 days old) by GusHerb (Chicago/NWI)        

I simply don't care for them because they're always priced higher then Home Depot and Menards. Let alone some of their policies and non existent customer service. HD isn't much better though, and they've been replacing everything in the store with garbage quality store brand shit that's been pissing me off. After that I started going to Menards more for certain things and it appears they might be doing the same with more stuff... 


In the end I don't care much for any of those stores and wind up ordering online when I absolutely refuse to settle for junk.

Post# 937422 , Reply# 11   5/9/2017 at 19:02 (382 days old) by Yogitunes (New Jersey)        

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not saying all, but there are ones that do what they are supposed to, and ones that try to get away with, or OVER on someone if they can.....using the cheapest basic system...

there are ones that if they can get away with charging higher amounts, and delivering a substandard system, they will......

if the guy who built my house knew anything when it came to putting in the heating and water tank in, I wouldn't had to redo it with the proper equipment....he just went along with what they told him without gathering his own information first...

believe me, if I could get the original installer to come back and install what was supposed to be put in, in the first place, and at his expense, I would have....

plus, the new system is a bit overkill, my choice, but works like a charm....and like its supposed to....

believe it or not, the creature comforts of a business like Home Depot/Lowes, or any business for that matter, is for the customer, not the employees....granted yes, your working and building up a sweat, BUT its the customer walking in from the hot humid outside temp, into a slightly cooled area is to prevent the SHOCK of temp changes from one extreme to the next, especially for seniors, that sort of shock could cause a medical condition for them....

Post# 937426 , Reply# 12   5/9/2017 at 19:22 (382 days old) by duke ()        


I agree that there are shady installers.I was merely pointing out that the owner/builder of the structure usually picks which mechanical systems are actually installed.Usually the cheapest wins out.

Shady incompetent contractors are another issue and man could I tell some stories.

Glad you finally have gotten yours working properly.

Post# 937953 , Reply# 13   5/12/2017 at 08:47 (379 days old) by Davey7 (Chicago)        

Are you talking about an air curtain at the doors or general ventilation? I keep seeing articles and ads pushing the various destratification systems, either fans or... Maybe that's what's being done?

Post# 938249 , Reply# 14   5/13/2017 at 08:44 (378 days old) by fan-of-fans (Florida)        

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I miss the huge round HVAC diffusers that stores used to have back in the 1950s, 60s, 70s, 80s.

I noticed around the late 1980s the warehouse-style stores started going to these roof top units where each having a single vent. That's mostly what you see in today's ceiling-less big box stores. And even store with ceilings started around then, such as my Kmart has this system from the early 90s. I'm not sure what older Home Depot stores used, maybe they used them even earlier.

Although most new supermarkets I see still use the ducted systems, and a few even use the round diffusers. I think Walmart still uses ducted systems too in their new stores but not sure.

Post# 938905 , Reply# 15   5/16/2017 at 21:25 (375 days old) by mayguy (Minnesota)        

What you're seeing is the exhaust fan to use to clear the building from smoke or any other harmful product in the air..

We have them in our store, and I was told by a co worker who was there for the "smoke" test, and he said the building was cleared in 5 minutes when these fans kicked in.

Post# 938906 , Reply# 16   5/16/2017 at 21:29 (375 days old) by mayguy (Minnesota)        

Also, We have the roof top units, and avg 20 ton per unit. Our store has 12 of them, and they all have the economizer on it.

Post# 938915 , Reply# 17   5/16/2017 at 22:42 (375 days old) by GusHerb (Chicago/NWI)        

Our Kmart has the massive round diffusers probably original to the store, but they must've replaced the central chilled water cooling plant later on as they have very large RTU's on the roof now, but those diffusers remain in place.

The Menards down the street that is also in an older space has those large diffusers too and they still have the original central cooling plant in place. The wal mart by my house has the square lay in diffusers in the drop ceiling which are from the early 90s or so.

Oh and pretty much every Target store uses those giant square diffusers which I've always thought were interesting. They used to be flush with the ceiling then in more recent remodels they replaced them with ones that protrude down a few inches - possibly to reduce dust streaks on the ceiling tiles(??)

Post# 940256 , Reply# 18   5/25/2017 at 20:10 (366 days old) by fan-of-fans (Florida)        
Square vents at Walmart

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That's what our Walmart (also from the early 90s) has as well, with one big square or maybe two. The grocery section was built on in the late 1990s and has the exposed ductwork with vents on the sides.

I don't think I've ever seen a Walmart with round vents, the oldest ones I've been to were early 80s and had same white square vents that had maybe three squares.

Our old Publix, before it was remodeled had the huge round diffusers and they were silver aluminum and had I think one big circle in the middle.

Our Winn Dixie still has white round vents from the 80s with maybe three circles even though it was remodeled in 2008.

The old Scotty's hardware from the 80s had the round vents also.

Post# 940258 , Reply# 19   5/25/2017 at 20:23 (366 days old) by wayupnorth (On a lake between Bangor and Bar Harbor)        

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It was 60 and crappy today and all the corporate stores had a/c on controlled by central command. Come on, put a thermostat in every store and let it regulate the temp.

Post# 940262 , Reply# 20   5/25/2017 at 20:45 (366 days old) by duke ()        

Probably not the temp you're uncomfortable with.Huge rooftop units that are not staged correctly sound like the issue.Mild temps along with high humidity are a disaster for big box store A/C systems.The compressor doesn't run long enough to remove the humidity,making you feel balmy.

Post# 940283 , Reply# 21   5/25/2017 at 23:13 (366 days old) by GusHerb (Chicago/NWI)        

Another big issue with commercial spaces being clammy is many of these systems don't have economizers but just have outside air dampers that the contractors set to full open. Makes for a terribly clammy environment in any weather when they do that, many times the systems can't even keep up on warm days. Terribly cheap way of doing things. The older places most of the time don't have this issue because those dampers aren't set to wide open or they're actually using economizers like they should be. 

Post# 945958 , Reply# 22   6/30/2017 at 06:19 (330 days old) by DaveAMKrayoGuy (Oak Park, MI)        
HVAC at Walmart, direct fron dreck in Bentonville!

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I'd heard our heat & a/c is controlled by our home office which explains why there are areas in my store than are dreadfully hot--the sweat pours right off of my while I work, among those complaining about the heat, to places painfully cold--such as the back of the store in the hallway where some of our lockers are...


Seems we might have similar equipment that you say are at Lowe's & Home Depot, and why there is that inconsistency, & the interior climate's unevenness...


(Well, need I say more? I can't think of much else, other than this, at the moment...)



-- Dave

Post# 949371 , Reply# 23   7/21/2017 at 23:55 (309 days old) by GusHerb (Chicago/NWI)        

These are the giant round diffusers in the Menards that occupies a former Zayres. In the second picture on the left you can see the fairly new BAC cooling tower they put in when they replaced the chiller system. I'm actually impressed they decided to keep the chilled water system instead of replacing it with RTU's like Kmart did some years back. The system works very well too, I could hear air rushing out of each diffuser and the store was quite chilly on the 90 degree muggy as hell day we had today. I really wanna see what the ductwork and air handler looks like, I think there is only one and it must be a behemoth serving that huge ductwork and 12 of those huge diffusers. You can really hear the air roaring out of them on the side of the store where the air handler is.

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Post# 952696 , Reply# 24   8/12/2017 at 23:46 (287 days old) by DaveAMKrayoGuy (Oak Park, MI)        
"What's Gnawing At Me!"

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OK, flashback time:

That dropped ceiling, with the huge round vents, and other appendages such as speakers, fire alarms, sprinkler heads, etc.

Not to mention those banks of florescent bulbs I drew pictures of, in my youth, replicating certain restaurants, stores and other places as such that I had been to...

(Somehow no detention, suspension, or any other form of punishment for doing in school, in lieu of classwork & productive studies--though I was sure the "Kick Me! sign on my back kid", regardless...)

Here's what was probably playing from my shopping cart infant seat view & earshot of what that pic up above reminds me of, as does my first Pat Boone LP purchase (had to find out about "Never Going Back" he sings at the end of The Beverly Hillbillies & its origin--hence it's at the end of Side 1, that I play after playing Side 2 first; this song ordinarily kicks off the album, but to me someone goofed, so I suitably after studying the track listing realized it IS meant to come on after the "Flip interlude"... Play Side 2's "Long Distance" kick-off, first!)...

-- Dave


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