ABOUT CASTLE A/C & HEATING

Josh Cartwright

Owner & HVAC Service Technician

In 2005, Josh Cartwright started working with Brian Spiwak of Castle Air Conditioning & Heating as his apprentice. He learned the ins and outs of the residential and commercial air conditioning and heating business. After a four-year stint in the finance industry in 2006, he returned to Castle Air Conditioning and Heating in 2010 where he completed his HVAC apprenticeship. In 2012, Josh earned his HVAC license and became the new owner of Castle Air Conditioning & Heating in 2014.

Josh briefly combined forces with Maxx A/C & Heating in 2018 as the HVAC license holder where he ran a profitable service department based out of League City and gained additional commercial HVAC experience. After Maxx A/C & Heating changed ownership, Josh joined forces with Garry Mack and resumed the operation of Castle Air Conditioning & Heating.

As a licensed HVAC contractor ( TACLA00051749C ), Josh holds a national certification through NATE, andEPA Section 608 Technician Certification . He graduated from Stephen F. Austin State University with a Bachelor’s of Business Administration in Finance.

Josh enjoys spending time with his family and friends. He and his family are members of Second Baptist Church – 1463 Campus in Katy, Texas near Cross Creek Ranch and Cinco Ranch.

Sarah West

Office Manager

Sarah West serves as the Office Manager and is often the first point of contact for Castle A/C & Heating customers. With deep roots in the Houston area, she is committed to ensuring every interaction is handled with professionalism, clarity, and follow-through.

Sarah has extensive experience in office management, customer service, operations, and logistics. Before joining Castle AC & Heating, she served as the director of a neurodevelopment center supporting children and families. She has also led and organized large volunteer teams through her long-standing involvement with the Houston Livestock Show and Rodeo. These experiences have shaped her calm, organized, and people-first approach.

A Houston resident since the age of five, Sarah is passionate about serving her community and believes locally owned businesses are uniquely positioned to provide exceptional care and accountability. Outside of work, she is a wife to Roger, a commercial diver, and a proud mom to her daughter, Alexandria. She also volunteers with organizations supporting underprivileged children and serves on the board of a Scottish charity dedicated to preserving clan heritage—values that reflect the honesty, loyalty, and trust she brings to Castle AC & Heating every day.

Gwen Stewart

Dispatcher

Gwen Stewart is a part-time dispatcher at Castle AC & Heating and one of the friendly voices you may hear when you call our office. She helps keep our customers, technicians, and schedules organized while making sure everyone who calls Castle feels taken care of.

With a degree in Communication Disorders, Gwen brings a natural ability to listen, communicate, and support others—qualities that make her a great fit for our team.

Outside of Castle, Gwen is a wife, a proud mom to her daughter Olivia, and a constant supporter of the people around her. Most of her free time is spent doing what moms do best—keeping up with Olivia’s busy schedule and running between school, dance classes, and competitions.

Whether she’s helping a Castle customer or cheering from the sidelines at a dance competition, Gwen is always there to lend a helping hand and keep things moving.

Keith Johnson

Detail Manager

A true jack of all trades, Keith Johnson brings years of hands-on experience, attention to detail, and a strong commitment to customer service to the Castle AC & Heating team.

As our Detail Manager, Keith plays an important role in our new construction projects. He works closely with Josh, our builders, and our team throughout the construction process to help ensure every project is completed to Castle standards and delivers a white-glove experience from start to finish.

From detailed inventory management and jobsite coordination to customer service and those important finishing touches, Keith is always willing to step in wherever he is needed. His versatility and dedication help keep our new construction projects organized and moving in the right direction.

Outside of Castle, family is especially important to Keith. He spends much of his time off with his family or fishing.

Andres Garcia

Service Technician

Andres Garcia joined the Castle A/C & Heating team as a Service Technician in April 2026, bringing with him a strong background in customer service and a passion for the HVAC industry.

Born and raised in the Houston area, Andres is bilingual and a graduate of a local HVACR program. Before joining Castle, he served as an Assistant Service Manager with H-E-B, where he developed a strong commitment to customer service, teamwork, and taking care of the people he serves. He brings those same values to every Castle customer and their home or business.

Andres’ dedication to teamwork started long before his professional career. In high school, he was a member of the marching band and also participated in Boy Scouts—experiences that helped build the discipline, teamwork, and work ethic he carries with him today.

When he isn’t helping keep our customers comfortable, Andres enjoys spending time with his family.

Garry Mack

Consultant

Garry Mack obtained a Texas State Air Conditioning Contractors License TACLB3350C in 1985 when the State of Texas started issuing licenses instead of each individual city issuing licenses. He owned and operated Home Services Air Conditioning & Heating from 1984–2001 before selling the business to a Fortune 500 company. He continued on in a consultant role for the next four years before founding Maxx A/C and Heating in 2005. Maxx A/C and Heating served residential, commercial, and new construction customers, providing HVAC service and replacement. Maxx A/C & Heating was sold in 2018 with 21 employees and 14 subcontractors. Garry currently serves in a consulting role with Castle Air Conditioning & Heating.

In his free time, Garry has been an active community volunteer serving as a firefighter since 2007 for the Seabrook Volunteer Fire Department and serving as president for the last decade. He was also elected to Seabrook City Council where he served from 2008–2011.