Air conditioning in a Dry Cleaners
I am working on a project for a Dry Cleaners. One of the requests of the Dry Cleaner Owner is to add additional air conditioning to the store. The store is very hot and extremely humid. The heat generated by the washers, dryers, dry cleaning unit and the massive steam generating unit drive the temperatures to excess of 120 degrees. The humidity is extremely high from all of the steam pressing units.
It would be impossible to work under these conditions if the existing air conditioning units did not have air ducts that blow directly down on the employees at their individual work stations. If you walk a foot or two away from the work station, its like stepping into a sauna.
My HVAC sub contractor will be doing heat load calculations to determine the additional amount of air conditioning required.
The owner of the dry cleaners mentioned to me that he had heard of air conditioning units the are specifically designed for high heat and humidity areas like dry cleaners, commercial kitchens, pool sauna areas etc.
I have never heard of special high heat and high humidity air conditioners. I called Bryant and Rheem HVAC manufacturing companies and they have not heard of these speciality air conditioning units.
Has anyone heard of such an air conditioning unit? Any suggestions would be appreciated.
Replies
maybe you need to remove the heat instead of cooling the air
Ain't that the same thing? Air conditioners remove heat. Exhaust fans remove heat. Can't remove the heat source ... it's his livelihood.
"Can't remove the heat source ... it's his livelihood."
Sure you can, it's called insulation. Maybe some retrofit fit insulation on pipes and machines and possibbly some more modern energy efficent machinery would help. get rid of the heat at it's source.
I stand corrected ... thanks for the additional point of view.
Although insulating isn't removing the source of heat (although it is a possibility depending on the equip/process ... the part I know zip about at this point) ... and buying new energy efficient equipment many not be in the cards, either.
But, to make decisions and solve problems we must look at the WHOLE picture ... which is what you are helping to do!
Air conditioners remove heat. Exhaust fans remove heat.
Well, really, exaust fan only moves air. If the replacement air is cooler and/or drier, some heat exchange will occur. If the exhaust fan is pushing air that is 88º at 40% RH out, but the replacment air is 91º at 47%RH, you might not see much heat "removed."
Air conditioner really is a plant for air chilled to a given deltaT and RH. If you limit the air volume circulated, that air will cool and dry, but only to the extent that the building is not heated the conditined air, or the ambient condition of any make-up air coming in.
Here in town, down here about 29ºN (where we peaked about 93º @ 44% RH today), most of the dry cleaners seem to run all doors open in the back with banks of exhaust fans between the trusses along one wall. There's an a/c unit pumping chilled air into the customer area, and individual hanging units at each machine. Costs of running the gear virtually outdoors seems to be part of the cost of doing business.Occupational hazard of my occupation not being around (sorry Bubba)
Right you are ... Where I come from exhausting air is usually an improvement overall.
Designed right, an AC system will control the temp and RH to the proper levels for the situation it is in.
Which is why we asked where the problem was located.
29 degN? Latitude? Where is this?? Which hemisphere?
Which hemisphere is 29 degN? Think about it. You can do it.
Edited 6/22/2008 11:00 pm ET by Ozlander
East or west?
29 degN? Latitude? Where is this??
Within about 2/3 of a degree of latitude of being right on the Tropic of Capricorn. At noon on Friday last the sun peaked at 89.323º above the horizon at solar noon (rose just shy of 30º North of East, set a similar amount norht of West that day, too). Makes working out sun shading fun.
If you were to take out a map of the United States, and set your focus to Texas, then draw a line from Waco to Houston, that latitude would be about halfway along said line.Occupational hazard of my occupation not being around (sorry Bubba)
When I do trusses for restaurants, they often have 2,000# rooftop HVAC units.
It might be a good idea to ask whomever does that kind of construction what kind of units they are.
A word of caution: if you touch it, you own it! By that I mean the HVAC system.
If the applicable code requires 30 cfm/person for an occupany of 30 people/1000 sf (which the International Mechanical Code 2003 does) and you don't provide it, you could be on the hook to do so.
Point exhaust as BB mentioned, is the first part of the solution. The other necessary parts are makeup air and controls.
You've entered no profile information so I don't know in what part of the world you're working. It makes a difference in how the makeup air is provided.
Beyond exhausting the heat, vapor and fumes, (and providing adquate makeup air)cooling this place would be like cooling a commercial kitchen. Standard commercial types of equipment can be used. Is your HVAC sub familiar with commercial/industrial applications? That is important, not critical, but important.
I would suggest you contact either a local commercial equipment supplier and/or a local HVAC engineer that knows the ropes.
What Tim said. Drycleaners are special when it comes to equipment.
There is a reason clothing factories were called sweatshops. You need steam to run them and steam is hot. Duhhh.
Spot cooling is the only way to go in order to beat the botsball index. But the chemicals are real hard on equipment. Get the suppliers involved.
You've done a couple and now you can design a system w/out knowing many of the specifics?? You should take more care in providing a response that is helpful w/out telling them what [you think] the design should be.
I know very little about the equipment in dry cleaners, but if it is possible to provide 'spot exhaust' at each equipment, you will be ahead of the game. That exhaust should be accompanied by spot ventilation ... like the modern commercial range hoods. That way you deal with the heat/contaminated air before it affects the occupants and your energy pocketbook.
If your HVAC contractor doesn't know ... don't use him. Consider a good HVAC engineer.
BTW - normal cooling systems will remove humidity ... and if actually designed, they will remove all that you want. When warm, moist air hits a cold coil ... it will (and is designed to) wring out moisture. That is why there is a condensate pan and drain tube in the unit.
Rather than asking someone for high heat, high humidity air conditioners, just tell them your situation ... it's their job to design a solution.
You can get a large system to cool and dehumidify the space .... but it will cost you in energy consumption. I think your best first choice is find someone who can provide localized exhaust/ventilation ... your existing cooling system may be large enough to handle the rest of the load.
BTW - where are you located? Someone mentioned that ... it can be important in making choices.
Since I know little about your specifics, I'd suggest you consider a reputable engineer ... it would be well worth his fee. Contractors that design can not have your best interests in mind. Remember ask for all of the RESULTS you want, don't tell them what equipment to put in ... unless you want to buy the liability for the design. Consider asking an engineer for a couple of concept options to help you make an informed decision.
If you end up surprised at the equipment cost ... consider this. Take your general average cost per hour wage burden you pay the employees (gross total burden including OH and benefits). Add up all the employees. Now take a percentage time they think about comfort rather than their job ... that is how much money you are throwing away due to discomfort. And that doesn't include all the other costs associated with e.g. employee absenteeism due to discomfort, sick leave, turnover, etc. If you are a serious business man and care about both your profits and your employees ... do it right; anything else isn't much more than a bandaid.
There are a couple of whiners here that feel that I have provided "plans and specs" for the air conditioning system in a dry cleaning facility.
What follows is the email I sent in reply to the person that whined to me:
I missed all of the exchanges that were deleted. Having read many of you posts over the last few years concerning HVAC matters, I can state that you have a great deal more knowledge that many/most here, specifically inlcuding "clueless". I have spent the last twenty years as a mechanical engineer, working for much of that time as a designer of commercial and industrial HVAC systems. I am presently employed by the premier manufacturer of HVAC equipment in the world as an application specialist & engineering consultant. I do know a little about which I speak. Don't let a little pi$$ing contest deter you from future contributions here.
Thanks for the kind words.
The OP asked for some information, and I provided some info based upon real world field conditions. I never stated that it would work, provided brand names of the installed equipment or the name of the cleaning facility.
I hope the OP got something out of it before I deleted it.
Sorry to cause any grief. The way it was presented was that if they put in x, y, and z tonnage, it would provide a solution. As if the guy had knowledge about the design. In reality, as he himself stated, he simply installed what was designed and apparently had zero knowledge of the design criteria or even the issues involved.
Just because he installed it doesn't mean he understands it or is in a position to assist. He may be very competent at installing 'as designed'.
If you are an engineer, provide some feedback that can actually help this guy understand the ins and outs of his situation a little. That's what this forum is about. Even if he goes to an engineer to help him, he has a better understanding of the issues and can speak more intelligently with the engineer ... and ultimately make a more informed decision for himself.
I frequently see 'experienced' design engineers give their clients what they ask for (even if it is BS) no comments made (which I understand the need to not bite the hand that feeds you) .... or they schlepp a design together that is the least amount of effort for themselves and to heck with issues like maintenance, energy, comfort, etc. (they may pick one and leave it at that).
Just trying to keep the discussion meaningful and have value.
I have provided some information and feedback to the OP, hoping as the thread progressed to extract some more details from him.
In general, as I stated earlier, any process or machine/equipment that is a point source of heat/vaopr/fumes must be provided with exhaust. When exhaust is required, makeup air is required. If those two are addressed, supplemental cooling is relatively simple. My further recommendation was to take this up with some local experienced people, i.e. a commercial HVAC equipment supplier and/or and HVAC engineer, to get specifics.
My reference was to a commercial kitchen, which aside from the unique characteristects of kitchen exhaust (type I hoods, grease ducts, fire suppresion) systems, would be treated very similarly.
And just as a point of interest, insulation on equipment doesn't do a lot in a drycleaners. They use steam to press clothes. Steam that is hotter than 212.
I didn't know insulation didn't work above temps of 212 degF ... Interesting. Setting the specific dry cleaning processes aside (which I know next to nothing about), insulation on high temp applications is common to control heat loss. If the process isn't contained w/in a container ... insulation of course does you little good, but some of the process has to be w/in a container (starting w/ a steam generator/boiler), so insulation can help control those parts of the process.
Trust me, I know about high temp process. Want to come play with a 25,000,000 btuh water heater? High pressure boilers? Railcar steam cleaning systems?
The point is you don't know about dry cleaners. And the discussion is about drycleaners.
They use steam to press clothes. Pretty much all the steam made ends up in the air. Kinda of hard to insulate air.
The boilers are insulated.
You could put 6" thick insulation on all the piping and it is still going to be hot.
And if the ambient temps are too low, the quality goes down. It's why clothing plants were/are called sweatshops.
So ... since a lot of the heat is expended in open air ... you advocate forgoing the insulation on piping?
Personally I like to address each issue ... boiler, piping ... insulate. Open steam use ... controlled exhaust and make-up air to minimize energy while maximizing comfort. I'm guessing there are products available for that application ... I've been in the energy business long enough to know that would be something that a manufacturer would most likely provide.
But ... leave it to professionals who will [theoretically] provide the best solutions for this guys application. Assuming he is able to locate a professional that will look past the end of his nose and give the guy real service and be willing to work an honest hour for his pay. There may be many issues that the owner and designer needs to consider that this batch of 'experts' simply don't know about.
Bragging about what big cool systems you've worked on will not help this guy with his problems. Provide him with good information about the types of issues he faces will. Educate him a little about the science will help. I've provided what I consider some food for thought based on my experience in energy and comfort. The processes are similar to many in other applications, so the concepts are still relevant. Hopefully someone who knows more about some particulars of this application can fill in some gaps and then the guy can make more informed decisions for himself ... after all, he's the one that will have to pay for it and live with it in the end.
I ain't bragging about big cooling projects. I was talking about big heat. Know the difference? Just providing a resume.
You don't get it do you. It is a drycleaning plant. Nothing high tech. They use live steam that creates heat and humidity.
Betcha a hundred milkbones everything is already insulated.
But they let the heat out of the pipe.
There is no magic bullet here.
Go walk in the back of one and work for a couple of hours and then come back and talk.
If there was a product that was cost effective that provided cooling it would already be in every plant in the world.
BTW, its been the same basic technology for over what 60 years. Strange how they survived till now working in the heat.
Edited 6/26/2008 12:39 am ET by rich1
Pretty much covers the points I made, I think, too.
I may not be an engineer, but in order to deal with dynamic situations, you need to know a little about design.
I understand that there may be design compromises, balancing issues like initial cost, efficiency and providing some comfort cooling.
I have noticed a couple of things in the mechanical trades:
(1) Architechts are good at drawing things.
(2) Engineers are good at designing things.
Neither of the above, in my experience to date, are good at installing the things they draw or specify. Note that I clarified "in my experience" so I am not making a blanket statement regarding all.
And, when there is a problem with design or engineered specifics, neither of those groups of professionals will provide a workable solution in a timely manner.
Timely as in providing answers or solutions as needed as the project progresses... the project with a completion date.
And, when the engineer needs to commit to a change, they waffle- or provide conditions that must be met which result in no net change or commitment.
I am on an engineered project now, and it sure seems like no one at that company used a tape measure or verified site conditions when creating the drawings. They also have product specifications that create more space and installation issues. Even though their drawings will not work as engineered space-wise, they still get paid and the project still moves forward.
Someone has to deal with it.
Mechanical companies do not have the luxury of verifing site conditions on every bid job because that takes time, and no one will pay for estimates. So they have to get it in the ballpark and hope that nothing big was missed. I doubt all project estimators can look at a large project and submit a bid without missing anything at all when the plans are released two weeks before the start date.
I am that someone that has to deal with it in the field after all the "professionals" create the project.
I do not have to engineer the systems, but I have to remain faithful to the design intent.
I also need to point out things that I know won't work, but ultimately it isn't my responsibility.
Sometimes, it doesn't work, but if it is put in "as designed and engineered", then I am in the clear :)
How about some lateral thinking....forget about trying to improve the building air conditioning system, and get one of these for each employee: http://www.coolshirt.net/industry-single-user.html They're a popular accessory for race car drivers or for other people working in hot environments.
Amen to all that......
I wanted to share something that was sent to me, and my response.
They get paid ... as I assume you do.It would have been most helpful to know that you were simply the installer and really had no experience in the selection, design, or concept of the systems installed. I just read it like you were recommending x and y ton units for cooling and that was it.You were repeating design specs that were done by someone else whether or not you agreed w/ the design. Ultimately that doesn't seem to me to be of much help to the OP.Kind of like ... yeah I installed some 100,000 cfm air handlers in a building ... hope that helps you with your situation. Or ... I put a V-8 in my car ... several times ... doesn't help me much with my Honda, does it?The guy is looking for relevant information to help him make a more informed decision, not just what people have/haven't installed w/out information about the underlying details that might help the guy out.
There isn't enough information in the original post to offer any workable advice.
No location.
No equipment info.
No load info.
Just like darn near any other post on darn near any other subject in the Breaktime forums. (a couple of words are edited there so it doesn't go into the Tavern).
Yet, some people continue to offer suggestions from too little information in an effort to help out on a variety of subjects.
I would hope that someone asking for information/advice on a public forum is willing to accept it for the price paid.
I would also hope that those using the advice do whatever is necessary to ensure that the information given is correct and applicable.
The equipment I listed was from an engineered set of drawings for a dry cleaning facility. I would bet that most dry cleaning facilities being built today are pretty similar as long as the scale of the operation is comparable. The facility I worked in fits into a basic strip mall location... about 40' wide and about 80' deep.
Given the wealth of specific information provided in the original post, you know, the information needed to engineer a solution for a specific dry cleaning facility, I see nothing fundamentally wrong with the information I provided... whether I engineered the drawings or not.
I would bet that the equipment I listed is the best compromise between an owner wanting to provide reasonable comfort for employees and customers without impacting his/her bottom line.
If you are able to provide an engineered solution from the information provided, then please do so.
I have seen large blisters of trapped moisture above a dry cleaner-laundry. (flat roof) I had to put about 20 vents on the roof to relieve the the moisture. They were not power vents. Just 3 inch pipes with a cap to keep the rain out. It bled off a lot of moisture and made the interior more comfortable.