Company lists · Data refreshed September 2026

Top 25 Hvac engineering firms based in Houston, United States

Name: Hvac engineering firms based in Houston, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 203 companies tracked

RevenueBase identified 203 hvac engineering firms headquartered in Houston, United States as of September 2026 and tracks 4,248 professional contacts across them, including 1,797 with verified work emails. Houston is the largest hub.

This list covers hvac engineering firms headquartered in Houston, United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 16, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 16, 2026 86% judged on-target in blind review

203Companies

4,248Contacts tracked

1,797Verified emails

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The 25 largest hvac engineering firms based in Houston, United States

Ranked by team size

Top 25 of 203 hvac engineering firms based in Houston, United States, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to hvac engineering firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Comfort Systems USA	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	10001+	1,330 contacts →
	Indirect evidence “Comfort Systems USA \| Quality People.” Source: RevenueBase Database · checked Sep 16, 2026
2	DBR	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	201-500	227 contacts →
	Partial evidence “Founded in 1972, DBR has evolved into the premier MEP engineering firm in Texas, providing mechanical, electrical, and plumbing engineering services, as well as building…” Source: RevenueBase Database · checked Sep 16, 2026
3	WAY Engineering, LTD	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	501-1,000	175 contacts →
	Partial evidence “Way Engineering's quest for building excellence began in 1918 when a modest, but dedicated refrigeration business opened its doors in Houston, Texas.” Source: RevenueBase Database · checked Sep 16, 2026
4	Shah Smith & Associates, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	134 contacts →
	Partial evidence “Shah Smith & Associates, Inc.(SSA) is a 120+ employee Mechanical, Electrical, and Plumbing (MEP) consulting engineering firm with offices in Houston, Austin & Dallas.” Source: RevenueBase Database · checked Sep 16, 2026
5	Letsos Company	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	201-500	115 contacts →
	Indirect evidence “In 1953, James N.” Source: RevenueBase Database · checked Sep 16, 2026
6	Custom AIR Products & Services, INC	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	201-500	114 contacts →
	Partial evidence “Custom Air Products & Services, Inc.(CAPS), an AirX Climate Solutions company, is a full-service HVAC company that specializes in the design, construction, installation…” Source: RevenueBase Database · checked Sep 16, 2026
7	Gray Mechanical Contractors, LLC	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	88 contacts →
	Partial evidence “Gray Mechanical Contractors is a licensed HVAC and Plumbing contractor providing construction services for General Contractors and building owners throughout Texas.” Source: RevenueBase Database · checked Sep 16, 2026
8	APS Building Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	201-500	85 contacts →
	Indirect evidence “APS is dedicated to building partnerships that enhance the comfort and productivity of our clients and their teams in the workplace.” Source: RevenueBase Database · checked Sep 16, 2026
9	Raven Mechanical, LP	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	72 contacts →
	Partial evidence “Raven Mechanical, founded 1979, is a full service mechanical contractor specializing in Plumbing and HVAC service and construction.” Source: RevenueBase Database · checked Sep 16, 2026
10	Wylie Engineering	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	66 contacts →
	Partial evidence “Wylie was established in 1988 and has grown steadily to become a leading MEP engineering firm in Texas with offices in Houston and Austin.” Source: RevenueBase Database · checked Sep 16, 2026
11	Isani Consultants	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	66 contacts →
	Partial evidence “Isani Consultants, L.P.(ISANI) is a multi-discipline consulting engineering firm established in with our offices located in Houston, Texas.” Source: RevenueBase Database · checked Sep 16, 2026
12	DWD International, LLC	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	64 contacts →
	Partial evidence “Founded in 1974, DWD International designs, manufactures, installs, and maintains industrial HVAC, pressurization, filtration and control systems that can withstand the most…” Source: RevenueBase Database · checked Sep 16, 2026
13	MEP Green Design & Build, Pllc	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	53 contacts →
	Partial evidence “MEP Green Design & Build, PLLC,(MEPG) is a full-service engineering firm made up of a dedicated team of professionals offering expertise in Mechanical, Electrical, Plumbing and…” Source: RevenueBase Database · checked Sep 16, 2026
14	Har-Con Mechanical	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	50 contacts →
	Partial evidence “Founded in 1955, HAR-CON is a full service mechanical contractor well versed in Plumbing and HVAC.” Source: RevenueBase Database · checked Sep 16, 2026
15	I. A. Naman Associates, INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	46 contacts →
	Indirect evidence “Since 1947, I.” Source: RevenueBase Database · checked Sep 16, 2026
16	Convergentz	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	42 contacts →
	Indirect evidence “As a technology leader and master systems integrator, Convergentz integrates IT and traditional building system functions to improve Building Performance, Environmental Comfort…” Source: RevenueBase Database · checked Sep 16, 2026
17	WAY Companies	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	42 contacts →
	Indirect evidence “Way Companies is a full-service commercial and industrial HVACR contractor delivering mechanical design-build, preventative maintenance, emergency service, retrofits, and building…” Source: RevenueBase Database · checked Sep 16, 2026
18	Comfort Systems USA	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	41 contacts →
	Partial evidence “As a leading HVAC retrofit, design, build, and services firm based in Houston, Comfort Systems USA - South Central specializes in installing, maintaining, and upgrading mechanical…” Source: RevenueBase Database · checked Sep 16, 2026
19	RDI Mechanical	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	39 contacts →
	Partial evidence “Since RDI Mechanical has been Houston's go-to commercial HVAC and mechanical contractor.” Source: RevenueBase Database · checked Sep 16, 2026
20	Roessler Equipment Company	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	32 contacts →
	Partial evidence “Founded in 1963, Roessler Equipment Company is the leading supplier of commercial HVAC products in the Houston, Texas region.” Source: RevenueBase Database · checked Sep 16, 2026
21	Infinity Systems, INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	30 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 16, 2026
22	Refrigerated Warehouse Construction Company Rwc, LLC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	29 contacts →
	Indirect evidence “Refrigerated Warehouse Construction is a Design/Build Refrigeration company.” Source: RevenueBase Database · checked Sep 16, 2026
23	Collaborative Engineering Group	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	26 contacts →
	Partial evidence “At Collaborative Engineering Group, we believe the best solutions come from working together.” Source: RevenueBase Database · checked Sep 16, 2026
24	K&r Mechanical Services LLC	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	26 contacts →
	Partial evidence “We are a full-service commercial HVAC mechanical contractor with over 35 years of experience in the field.” Source: RevenueBase Database · checked Sep 16, 2026
25	United States Home Services	Indirect evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	11-50	25 contacts →
	Indirect evidence “At our company, we specialize in offering comprehensive heating and cooling services to ensure optimal comfort in every season.” Source: RevenueBase Database · checked Sep 16, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: hvac engineering firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names hvac engineering firms.
Partial evidence: Its own public description names part of hvac engineering firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name hvac engineering firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 203 hvac engineering firms based in Houston, United States

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Hvac engineering firms based in Houston, United States at a glance

As of Sep 16, 2026

42.3%Verified-email coverage

20.9Average contacts per company

11-50Median size (employees)

100.0%Largest-city concentration · Houston

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

10001+

Email recency for this list is measured across the whole United States list rather than for Houston, so it is reported there. Company counts and contact totals on this page are exact for Houston, over 203 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among hvac engineering firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in Houston, United States whose own description of what they do matches “hvac engineering firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names hvac engineering firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among hvac engineering firms, and records with no verified work email. Companies headquartered outside Houston are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 1,797 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 16, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Hvac engineering firms by metro in the United States

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names hvac engineering firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many hvac engineering firms are there based in Houston, United States?

RevenueBase identified 203 hvac engineering firms headquartered in Houston, United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Comfort Systems USA, headquartered in Houston, tops this list with the largest team on record.

Which city has the most hvac engineering firms?

Houston leads with 203 headquartered companies, followed by New York (199) and San Antonio (95).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,797 verified decision-maker contacts tracked across these 203 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 16, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.