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View Full Version : Ive been asked to design/install AC system....where do i start!?!?



halfcan
24-01-2010, 10:09 PM
Hey everyone

Ive been doing Air Conditioning install for roughly 3 years now and have just come out of my apprenticeship (well....finishing off my 3rd and final year at college), and the majority of work through my company is generally air conditioning installation (VRV's/single splits etc, the basics really). All the work I've done has purely been installing the equipment, and all the design side such as choosing the correct units and materials has always been out of my hands, and done in the office (which has nothing to do with me). I've recently been approached by a friend who runs a gym and asked me if I could sort out some air conditioning for them. I genuinely really want to do it, but have no idea where to start from. Is it a case of calculating all the heat loads of the room, and finding a system which will provide the correct cooling capacity? Any form of advice would be absolutely great!

Brian_UK
24-01-2010, 10:16 PM
Why not ask your company to provide the service or is your friend hoping for a cheap install?

But, in answer to your questions, yes, calculation and equipment matching.

eggs
24-01-2010, 10:43 PM
Your best bet is to go to the wholesaler you are most familiar with and who recognise you.
Kooltech, Thermofrost, Cool Designs, even Daikin will be more that happy to do a survey and heat calc for you as long as there is a good chance you will win the job.

Eggs

dougheret0
05-02-2010, 08:18 PM
The suggestions above are good, but if you want to understand what you're being told, let me modestly recommend my book HVAC Design Manual – A Mechanical Designer’s Guide to Design of Small Commercial and Institutional HVAC Systems which is available for free download at www.nettally.com/doughert (http://www.nettally.com/doughert). It is unfortunately only available in IP at present, but the book is a road map of how to start with a clean sheet and design a functional and satisfactory system, and the units problems do not detract from this.

Can't help with the installation part though.

solas
05-02-2010, 09:46 PM
There are a number of important considerations when designing the air conditioning system for a gym.
These include but are not limited to;

1. ventilation requirements and distribution - this is critical to the satisfactory operation of the gym as fresh air requirements per person must satisfy the increased metabolism rate. fresh air volume will be dependent on the capacity of the gym. room air distribution through proper selection of terminals is important so as to avoid hot pockets and dumping etc.

2. there are a number of cooling loads you must consider before selecting the cooling equipment- 1. casual gains such as people, luminaires, electrical exercise equipment. - 2. ventilation load - this can be high and is dependent on the gym capacity - 3. solar gain -

3. users control interface and zoning- localised or slave control, this depends of the equipment layout and occupancy profile. its an important detail that can only be agreed through discussion with the owner/operator.

4. space considerations for installation and maintenance - as you are aware, there are many indoor variants for every application: concealed ducted, flush mounted cassettes, wall mounted or floor mounted console units etc. Alternatively, if you have very generous ceiling space and the budget is limited, there are 30kW in-ceiling ducted units that could be suitable. Dont forget provision for condensate drains and max lift with integrated pumps is typically <300mm.

Its really difficult to know without some idea of the salient characterisrtics such equipment layout, room layout and owners specific requirements.

Edit: This paragraph edited by Solas
It is important to note that any manufacturer, including AC equipment generally can only design the part of the system that contains their equipment such as indoor/outdor units, refrig. piping & controls. Electrical and mechanical systems such as power, ventilation system, drainage system, primary plant etc. design and specification lies with another party. If the AC system consists of only a small number of reverse cycle splits, this doesnt apply. However, if the system is not limited to this, you need to take full responsibility for design, commissioning and certification. http://www.refrigeration-engineer.com/forums/images/VA_RE/misc/progress.gif

I would strongly recommend visiting at least 1-2 gyms that are operating more than 1 full year and possesses similar characteristics noted above. Try to meet with both the gym operations manager and the buildings facilities manager or chief engineer depending on gym size. If you still feel unsure about certain elements and want to cover yourself, try approach a building services design engineer through one of your former projects.

It is always helpful to familarise yourself with the CIBSE text books as they provide best practice guidelines on areas related to building services such as a/c.

I dont want to make this sound like the design element is very complex but sound design can help keep your maintenance costs down and keep a smile on the clients face.

Best of luck.