Indoor Tennis Facility 1

[mpreble]

I am designing a new HVAC system for a new indoor tennis facility.
I have conducted loads as accurate as I can only to find that the +44k sf facility is needing 100 tons of cooling. I find that very hard to believe since there will be at maximum 24 people on the courts.
Any advice on indoor tennis courts?

 

[EnergyProfessional]

how did you determine load? i mean you mainly have ventilation etc.?

I mean it is your load calculation, how are we supposed to review it? Location, climate, design temps, envelope, ventilation etc.???? Are we supposed to guess?

 

[mpreble]

I was looking for suggestions. I ran a load through HAP
The location is in Owensboro Kentucky. The roof is R-30, walls R-20. According to the National Tennis foundation there needs to be 1-6 air changes per hour. That's a pretty wide range.
Just looking for some design guidance.
Thanks.

HerrKaLeun: "i mean you mainly have ventilation etc.?" Is that a question or a suggestion?

 

[chicopee]

so that means that you'll have six courts for players(=24 people)+ staff+ people waiting for play time+ visitors. What were the design temperature and relative humidity for outside and inside?

 

[MintJulep]

So how many air changes did you use in your HAP model? 1 or 6 or one of the numbers in between?

Tennis needs height to play. How high is your building? maybe 30 feet?

44,000 x 30 = 1,320,000 cubic feet.

At 6 air changes per hour that's 132,000 cfm

Just the sensible cooling might be around 240 tons for that.

At 1 air change per hour you still have 40 tons just for sensible cooling of the ventilation air.

So 100 tons doesn't sound like a completely wacky number.

 

[cry22]

In my opinion
such spaces should be substantially UNDER-SIZED, over-sizing is no good for such a space, intermittent occupancy

Use CO2 sensors for DCV (CV systems) and use total enthalpy wheels for outside air

You should look into 1000 to 1200 SF/Ton in such spaces - I see a 40-ton is more like it for such a space if you have say 200 people and no more than 15% glass.

 

[SAK9]

A good candidate for displacement ventilation in my opinion.

 

[cry22]

Indeed SAK, very good point.
I agree, this is a very good application for Displaced Ventilation. Interesting approach.
This is what these forums should be about - people should volunteer ways to solve the problem differently, better yet, eliminate the problem instead of improving the proposed solution by the OP.

I'd add to your suggestion if I may - One could supply air at much higher temperature (say 63 to 64) and even higher (as much as 70F) during low-occupancy (which is most of the time, i.e no competition), thus taking advantage of longer hours of air-side economizer and ignore lighting and roof from the load along the way. Adding cool roof technology reduces load even more.

You'd still combine with Total enthalpy recovery to your minimum fresh air intake

Now throw in some pre-cooling control method for pre-determined high occupancy periods, and you have removed the fear of equipment down-sizing.
If still afraid of down-sizing - One could up-size somewhat ductwork and have space for additional equipment to supplement the system (IF if happens to be undersized or fearful or record days).

If this is a single story facility, one could easily add natural ventilation or a combination of (PRV's on roof and open windows and doors between 70 and 75 outdoor temperature) and still get adequate comfort.

I'd look into hydronic in-floor radiant heat for heating if this is a new facility and it is in a cold climate. Solar thermal using low-grade heat (90 - 110) for in-floor radiant heat will go a long a way towards reducing heating costs.

Let me throw-in a different approach - if this is hot and dry climate, this space would be a very good application for evaporative cooling and you have removed 90% of air-conditioning - you don't even need to down-size since your energy (water) consumption is in direct relation with outdoor wet-bulb.

There is a huge opportunity for energy savings - you could look at possibly achieving LEED Platinum for such an application.

FEAR is what makes people do stupid things, such as over-sizing in high occupancy spaces. Fear that it may not work, what if we have record days, I don't want to get sued, etc.. One could get numbers on paper and a common sens presentation to owner and have him sign-off and be ready to add equipment IF it does not work. Have easy solutions to remove the fear as indicated above. Any owner would jump at a solution reducing his first cost, operating costs and improve air quality and comfort.

 

[dynamo78]

A+ for you Cry22, I used the same thermodynamic principle,Adiabatic Saturator,some places calls it "Air washer", for a covered tennis court I designed in a tropical country.Yes the country is humid but the players are sweating like nobody's business so its not an issue. Thats the best approach, now if you want lower than the wet bulb temp., then add a little PACU or whtever,just be creative.Engineers make things Possible.
Hope that helps, did this so many years ago.