Guestroom Outside Air – What are my options!? (Part 2)

Previously in Part 1 of this series, I briefly described the three most common methods for introducing fresh air into a hotel guestroom; Standard PTAC with open damper (Method #1); PTAC with two-stage system (Method #2); and a Dedicated Outside Air System (Method #3).

In Part 2, we will explore what some of the major hotel franchises, such as Hilton, Marriott, Starwood, Hyatt, IHG and Choice, require regarding guestroom outside air based on their most recent brand standards design manuals for select/limited service hotels.

  1. Hilton – Standard PTACs (Method #1) are not acceptable for providing ventilation air in Hilton properties. Hilton does allow two-stage PTACs to be installed in guestrooms (Method #2). However, when these units are used for providing guestroom ventilation, it must be accompanied by central dehumidifying makeup air units supplying at least 25 cfm per guestroom plus the required ventilation of the front-of-house and back-of-house spaces. In other words, if you use a Dr. PTAC or Amana DigiAIR PTAC for guestroom ventilation, you must provide an additional 25 cfm per guestroom into the corridor.  I reached out to Hilton about this, and their approach when using Method #2 is due to evidence indicating an inability of these units to provide positive building pressurization. (As well as the uncertainty that the proper PTAC units will be used for replacements in the future).  Ultimately, the preferred method for delivering outside air to guestrooms for most Hilton hotels is a DOAS (Method #3). One additional item worth noting is that Hilton Engineering is currently in the process of modifying the above requirements and many of these standards will change come 2016.

  1. Marriott – Similar to Hilton, Marriot does not allow standard PTACs (Method #1) for providing fresh air to a guestroom.  Unlike Hilton, when considering two-stage PTACs (Method #2), they do not require the additional 25 cfm of outside air per guestroom. In other words, if Dr. PTACs are installed, the DOAS tonnage is greatly reduced as no additional cfm is required for the guestroom space. A DOAS is still, however, required for supplying air to the guestroom corridors, BOH (Back of House), and FOH (Front of House) areas.  One other important item to note is that currently Marriott only allows the Dr. PTAC two-stage PTAC units. (Amana’s version has not yet been approved by Marriott). Ultimately, the preferred method for delivering outside air to guestrooms for most Marriott hotels is a DOAS (Method #3).

  1. IHG – IHG has no specific HVAC requirements for fresh air in guestrooms, so all 3 options can be used.  With that said, in most climates, they highly suggest properties avoid using standard PTACs (Method #1). ASHRAE 62.2 fresh air minimums must still be met for all spaces within the hotel.

  1. Starwood – Starwood has no specific HVAC requirements for fresh air in guestrooms, so all 3 options can be used. ASHRAE 62.2 fresh air minimums must still be met for all spaces within the hotel.

  1. Hyatt – Hyatt has no specific HVAC requirements for fresh air in guestrooms, so all 3 options can be used. ASHRAE 62.2 fresh air minimums must still be met for all spaces within the hotel.

  1. Choice – Choice has no specific HVAC requirements for fresh air in guestrooms, so all 3 options are available to owners. ASHRAE 62.2 fresh air minimums must still be met for all spaces within the hotel.

These three options for outside air delivery ultimately offer much different experiences for your guests and operating costs to your bottom line. Ultimately, hotel owners need to not only evaluate which option is required in the franchise standards, but also on the geography, weather and guest experience they are trying to achieve with their project.

If you enjoyed this post, please share it with your colleagues and subscribe to our mailing list below.  Thank you!