How we are different
At Diversified Mechanical Solutions, we deliver more than just HVAC service - we provide a premium experience built on precision, transparency, and long-term value.
When homeowners in Longview and across Cowlitz County, WA trust us with their heating and cooling systems, they receive advanced diagnostics using state-of-the-art tools. We measure airflow, refrigerant levels and pressures, and energy consumption to ensure your system is performing at peak efficiency.
This detailed performance reporting allows us to identify and resolve small issues before they become costly repairs - saving you money and extending the life of your equipment. As a proud dealer of the top-rated American Standard, we combine elite products with expert service to deliver unmatched comfort and peace of mind.
Whether you’re in Kelso, Castle Rock, Longview, or the surrounding area, Diversified Mechanical Solutions is your go-to choice for Premium HVAC service in Cowlitz County.
Heating and Air Conditioning
Residential Service $148.99
Commercial Service $174.99 (Hourly)
Commercial Service $174.99 (Hourly)
Keep your home comfortable year-round with expert residential HVAC services from Diversified Mechanical Solutions. Serving Longview, WA, our skilled technicians provide dependable heating and cooling solutions, including installations, repairs, and maintenance. Whether you're upgrading your system or need a quick fix, DMS delivers quality workmanship and friendly service you can trust—because your comfort is our priority.
Commercial Service $174.99 (Hourly)
Commercial Service $174.99 (Hourly)
Commercial Service $174.99 (Hourly)
We specialize in delivering top-tier commercial HVAC services tailored to meet the unique needs of businesses in Longview, WA. From energy-efficient installations to rapid repairs and routine maintenance, our expert technicians ensure your heating and cooling systems run smoothly year-round. With a commitment to quality, reliability, and customer satisfaction, DMS is the go-to choice for keeping your commercial space comfortable and efficient.
Residential System Replacement
Commercial Service $174.99 (Hourly)
Residential System Replacement
At DMS in Longview, Washington, we believe in transparency and trust—that’s why we offer upfront pricing on all residential system replacements. No hidden fees, no surprises—just clear, honest estimates so you can make informed decisions with confidence. Whether you're upgrading your HVAC system or replacing a worn-out unit, give us a call for a seamless, stress-free experience from start to finish. Let our expert team take care of your comfort with professionalism and care.
If you need help figuring out what size your system is, visit our blog page or give us a call!
Residential Heating and Cooling
New Construction
Both standard and mini split systems in custom homes are a lot of fun! You will get to work with our design team to create a system to ensure maximum comfort while pushing for optimal performance and efficiency. We go from Longview to Kelso to Toledo to Vancouver (sometimes even Portland).
Existing Residence
Does your house not have any conditioning? We can provide a plethora of ducted and ductless mini split systems. We will spend time with you and learn how you use the spaces in your house to design a system that will best meet your needs.
Service/Diagnostics
We want to keep your system running! We put forth a lot of effort to stay up to speed with the latest diagnostics technology and having weekly tech training classes for our guys. From furnaces, heat pumps, air conditioners, ductless heat pumps, we have the best service in Longview, WA
Maintenance
Just like changing the oil in your car, maintaining your HVAC is paramount to getting the most comfort with the least wear and tear. Keeping your system running efficiently is the best way to keep energy costs down while staying comfortable.
Call in to find out about our maintenance packages.
Do you Have Questions?
We don't expect you to know everything about HVAC. But, in the spirit of wanting to help you learn more, here is an FAQ blog for more information
Commercial Heating and Cooling
New Construction
We can everything from office spaces, shells, or specific designs for manufacturing. We work with American Standard for full ducted systems and Mitsubishi City Multi for room specific conditioning.
Existing Structure
We can do everything from a simple tenant improvement project to a full system redesign to a server room needing additional cooling and humidity control.
Indoor Air Quality
Breathe clean, fresh air with our indoor air quality services. We offer air duct cleaning, air purification systems, and humidification systems to keep your tenants healthy and comfortable.
Maintenance Plans
We offer in-depth diagnostics and reporting for our commercial maintenance packages.
We focus heavily on cleanliness of all aspects of the systems to maximize performance and minimize energy consumption.
Instead of reacting to failures, lets be proactive and plan your downtime.
Additional Services
Radiant Floor
At Diversified Mechanical Solutions, our mission is to provide affordable and reliable HVAC services to our customers. We strive to exceed expectations by delivering quality workmanship and exceptional customer service.
Duct Cleaning
We offer a wide range of HVAC services including air conditioning and heating repair, installation, and maintenance. We also offer indoor air quality solutions to improve the comfort and health of your home or business.
