Economizer? Yeah or Neah?

[halcali]

I'm putting two five ton rooftop units (nordyne 14seer duel fuels) in a small bar / music venue. Is it worth it to get an economizer? My concern is that a big problem with high capacity spaces is humidity. When the economizer kicks fully on, will the lack of an operating AC (since the economizer takes over) create humidity problems?

[BaldLoonie]

Can happen. Best bet is get an enthalpy control instead of just dry bulb temp changeover so if cool but humid, you don't economize. Some units will do stage 1 as economizer and stage 2 as compressor in case the economizer alone can't do it. Not sure how Nordyne does it.

[flange]

single enthalpy can cost you in both comfort and economy. Use a comparative enthalpy control if you choose to economize.

[genesis]

Suggestion set up the economizers on ventilation on demand using CO2 as your base. It would solve several problems at once. Here is a link to a white paper that was written on a job I did a few years back over seas.
http://www.genesisair.com/documents/...akesforIAQ.pdf

[allstar08]

single or dual point enthalpy is the way to go. Most cities require economizers
on anything over 2 or 3 tons anyway. They can save big $ and create a comfortable space.