About Us

John LeVan, Owner

John LeVan, Owner

Comfenergy, in Sterling, Virginia, prides itself in "creating a comfortable, energy-efficient, healthy home, and work environments by providing value through people, products, and processes". In over ten years of existence, 22 awards were given including, the 2020 #1 Dealer in the Network Award. This locally owned business offers insulation services, soundproofing, basement & crawl space services, home energy audit, and windows & doors inserts.


Services Provided

  • +Doors

    • Aluminum Door Installation & Replacement
    • Cellar Door Installation & Replacement
    • Diamond Plate Door Installation & Replacement
    • Door Glass Installation & Replacement
    • Door Repair
    • Door Screen Installation & Replacement
    • French Door Installation & Replacement
    • Front Entry Door Installation & Replacement
    • Hardware, Latches & Track Installation & Replacement
    • Man Door Installation & Replacement
    • Patio Door Installation & Replacement
    • Screen Door Installation & Replacement
    • Sliding Door Installation & Replacement
    • Steel Door Installation & Replacement
    • Storm Door Installation & Replacement
    • Vinyl Door Installation & Replacement
    • Wood Door Installation & Replacement
  • +Energy Audit

    • Blower Door Testing
    • Home Energy Audit
  • +Heating & Air Conditioning

    • Duct & Ductwork Installation
    • Duct Insulation & Sealing
    • Duct Repair
  • +Insulation

    • Air Sealing Services
    • Attic Hatch Insulation Installation & Replacement
    • Blown-In Insulation Installation & Replacement
    • Cellulose Insulation Installation & Replacement
    • Crawl Space Insulation Installation & Replacement
    • Fiberglass Insulation Installation & Replacement
    • Floor Insulation Installation & Replacement
    • Foam Board Insulation Installation & Replacement
    • Garage Insulation Installation & Replacement
    • Injection Foam Insulation Installation & Replacement
    • Mineral Wool Insulation Installation & Replacement
    • Roof Insulation Installation & Replacement
    • Spray Foam Insulation Installation & Replacement
    • Wall Insulation Installation & Replacement
  • +Radon Testing & Mitigation

    • Radon Mitigation
  • +Remodeling

    • Basement Flooring
  • +Sump Pump

    • Sump Pump Installation & Replacement
    • Sump Pump Repair & Service
  • +Windows

    • Aluminum Window Installation & Replacement
    • Bay Window Installation & Replacement
    • Bow Window Installation & Replacement
    • Casement Window Installation & Replacement
    • Double-Hung Window Installation & Replacement
    • Exterior Shutter Installation & Replacement
    • Fiberglass Window Installation & Replacement
    • Picture Window Installation & Replacement
    • Security & Storm Shutter Installation & Replacement
    • Sliding Window Installation & Replacement
    • Storm Window Installation & Replacement
    • Vinyl Window Installation & Replacement
    • Window Cleaning
    • Window Glass Installation & Replacement
    • Window Repair
    • Window Screen Installation & Replacement
    • Wood Window Installation & Replacement

Company Highlights

  • In business since 2013
By BRUCE
EXCELLENT SERVICE..WOULD RECOMMEND YOU ALL TO ANY AND ALL!
By Ruth
Was very happy with the results.Have forwarded all the information to my daughter as she has expressed a desire to have an inspection done.
By Michelle
5 Stars all around!
By Ann
The workers the day the job was done were very polite and considerate. But the one thing I would recommend is they clean up a little better. had they brought a leaf vacuum, they could have gotten all the little bits of insulation they left every where, and I wish they had cut the Styrofoam blocks on top of something as now I have tiny shreds of it in my grass and it will not biodegrade.
By Kevin
Anthony was professional and a pleasant person.
By Harry
Thank god I did choose your company.
By Tammy
The only thing I wasnt sure of is when they finished no one called to confirm that they were actually done. I was absolutely pleased with everyone and everything. I can already tell a difference in the comfort of my home. Thank you!
By John Barrett
on time and got right to work. Communicated well on what they were doing.
By Rich
Appreciate the professionalism
By Natalie
The job was thoroughly completed with more done at a lower cost. 
By Stacie
Thank you for such great follow up!!!
By StacieDavis
I can not say enough good things about the way the owners handled a situation that came up during an installation. They were both on top of it and made us very happy customers. THANK YOU!!! Things happen and the way they handled this was fantastic.
By Barbara & David
We had to wait for an appointment but it was worth it!! 
By Randall
Responsiveness, thorough explanation of recommended solution. Really worked w/ us to find the optimal solution that fit my needs.
By Joe
Your team did a good job sealing up the house. They put a hole in my ceiling from the attic, but fixed it. They blew insulation all over my baby's room including crib and clothes, but vacuumed it. They fixed all their sloppy mistakes.
By Stephanie
Very pleased with overall process, crews etc. Thank you for helping make my house more comfortable and energy efficient!
By Jade
Overall, very pleased. Would use again and recommend to others.
By Jacque
I was kept informed by email and I even had to change one of the days and it was easily worked out for me. I can't say enough about how pleased I am with the work and the courtesy from the crew and office staff
By Pam
Your men were excellent! They were very informative, a pleasure to work with, and finished faster than I thought they would. 
By Don
In the process of obtaining one more estimate and will then determine what direction to go.
Leanne P.
Ashburn, VA
I contacted Justin because our first floor master bedroom was extremely hot during the summer and very cold in the winter. When Justin came out, he did a thorough inspection and explained his findings in detail. He used thermal imaging to determine our bedroom attic had no insulation above it. Since there was no access to this area, his high-tech gear was able to see what we could not. Justin is extremely polite, extremely patient and knowledgeable. I would highly recommend Justin and the amazing Comfenergy crew to anyone.
Andrew A.
Ashburn, VA
I appreciated the time spent showing me the work and explaining what was going to be done.  The door adjustment for access was very good.
David O.
Ashburn, VA
Salesperson went over everything crew would do.  Friendly. Very good work.  They worked with us and explained everything as they worked.
Jenn S.
Ashburn, VA
Mike was very thorough in explanation of what our needs were.  He was very personable and great to work with.  All crew members were respectful and gave excellent customer service. 
Alison B.
Ashburn, VA
Shayne is great!  This is our second time using him.  The crew did a great job.
John R.
Ashburn, VA
I am 88, and have never had anyone doing work for me describe in detail what they were going to do, then explained what they had done.  Ismael was outstanding.
Michael H.
Ashburn, VA
The crew was clean and professional. 
Chris H.
Ashburn, VA
"We used Comfenergy to replace the ductwork in our attic, route two bathroom exhaust vents properly, and also to replace all insulation. This was a large job and they did an outstanding job. The pricing was fair and the quality of work was top notch. They took their time to explain everything to me as the job was being done and did a great job addressing my follow-up questions. I would easily reach to them again if a need comes up in the future."
Gordon M.
Ashburn, VA
    "Attic remediation work, i.e. sealing attic floor holes, duct work and replacing totally inefficient insulation.Company was totally professional from the consultant, Jason to the production crew led by Melvin. Good care was taken to keep their work area clean and cleaned up after the job. The team also helped to move furniture to make work spaces more accessible. Great job Comfenergy."
Phil H.
Ashburn, VA
"Carl came to my house to provide an evaluation and quote for attic insulation, as requested. He was extremely thorough and knowledgeable in identifying problems and potential problems in my house. Ultimately, it wasn’t an insulation issue and Carl didn’t push to “sell” a service I didn’t need. He went through every room in our house and provided input and resources for maintaining a comfortable home!"
Brent T.
Ashburn, VA
Hi Justin,   Appreciate the followup. We have definitely noticed a huge difference with temps in that room and we can now keep the door open all the time. The guys did a great job both inside and out.   Thanks again.   -Brent
Garrett L.
Ashburn, VA
Great guys!  Friendly, courteous crew.  Really went above and beyond to share how they did the job and had great attitudes about their work.   Carl was honest, friendly, and followed up well.  He took the time to explain insulation options in detail that gave me confidence in hiring Comfenergy.  
Matt S.
Brambleton, VA
The sales person answered all my questions and were very patient with me. The crew was excellent! I was told 2 days and they were told 3. They worked all day on day 2 so I could go back to work. 
S. E.
Aldie, VA
Mario is great to work with and he is a true professional. Mario did a great job! 
Gordon G.
Sterling, VA
"Thank you Comfenergy team! I’m more than happy with the quality of work and your team members. The project lead Myra was exceptional and everyone worked diligently, professionally, and long hours to get it done.  Even though there was an accident with the ceiling, your team identified it and fixed it quickly and professionally.  Needless to say It was a great experience!   Thank you Gordon" 
Tina N.
Sterling, VA
Wow! Comfenergy came to our house to conduct an energy assessment, and it far exceeded our expectations. With a special tool, Justin basically x-rayed our walls and was able to clearly show where we were losing energy in our home. He was able to determine that the builder had left some insulation out of one of our walls when the house was built, which ultimately contributed to our temperature control problems. He then gave us a three-tiered approach to correcting our situation. We highly recommend Comfenergy to solve insulation and energy loss problems. You have to see it to believe it!
Adam S.
Sterling, VA
Your prices aren't cheap, but I feel confident that Scott has recommended the right course of action for my house (which gets upwards of 105 degrees upstairs in the summer). I appreciate how prepared he was, how he took the time to listen to my concerns, and didn't try to sell me things I wasn't sure we needed. I had one guy recent told me that an attic fan was the way to go, but I felt like that wasn't the whole story. When I asked Scott if I needed an attic fan, he said I could get one, but having proper insulation would mean that we would be able to retain heat or repel heat where appropriate & not need one. I look forward to scheduling the installation & potentially having a follow-up with Scott in the dead of summer to see how much things have changed and if any other work needs to be done. I learned there was no insulation in parts of the house where there should have been, and that some insulation had fallen away from the wall.
John C.
Sterling, VA
Mike Dowling and Justin Dobson did an excellent job.  Very knowledgable and response -- addes a lot of value to remodeling project. John LeVan did a great job and I especially appreciate him coming out to the job when a question came up.   Ismael, Rafael, and Jordan did an outstanding job!  I will ask for them again as our remodeling contunes.
Michelle P.
Sterling, VA
Crew was very thorough, clean, friendly, accomodating, offered suggestions, and were happy to make changes.
Matt D.
Potomac Falls, VA
They did an excellent job.  Arrived on time, worked hard, and cleaned up well.  Thank you!
  • Frozen Pipes in Ashburn, VA - Before Photo
    Before
    Frozen Pipes in Ashburn, VA - After Photo
    After

    Frozen Pipes in Ashburn, VA

     The homeowner in Ashburn called,  as last year their pipes froze and they did not want that to happy again.This home i has always had issues with hot and cold spots, and freezing pipes in the winter.  We found cold air in the master bedroom attic to be getting around the batt insulation leading to the bathroom above.  This entire neighborhood of as notorious drafts and hot/cold spots. These homes have also dealt with many frozen water lines. The water lines were freezing almost 20 feet from the exterior of the home! Comfenergy installed 4" thick SilverGlo foam boards with heat reflective barrier on the attic walls.  

    Problem solved!!!  Foam board insulation in an attic keeps the cold air from travelling beneath the bathroom tub and the pipes from freezing.

    The homeowner will be more comfortable in the Summer and Winter.....but it lessened the draftiness of the home, and the pipes don't freeze any more!!!  

  • Increasing R-Value - Before Photo
    Before
    Increasing R-Value - After Photo
    After

    Increasing R-Value

    This home was having comfort issues on their top floors in the summer. Our solution was to increase the R-value by installing cellulose insulation and air sealing their attic.

  • Ashburn VA Cantilever gets spray foam to help insulate - Before Photo
    Before
    Ashburn VA Cantilever gets spray foam to help insulate - After Photo
    After

    Ashburn VA Cantilever gets spray foam to help insulate

    This Ashburn VA home had an uninsulated cantilever.  The external temperatures were impacting the condition and comfort in the room above.  We removed the base board of the cantilever on the outside of the house and filled the cavities with spray foam to insulate and air seal.  This will help to keep outside temperatures out and inside feeling the way the homeowner would like it to.  

  • Ashburn Va Attic Wall Insulation - Before Photo
    Before
    Ashburn Va Attic Wall Insulation - After Photo
    After

    Ashburn Va Attic Wall Insulation

    This Ashburn VA attic underwent a full transformation.  After our Home Performance Sales Pro performed a no cost inspection of the home, it was determined that the attic space would benefit from air sealing, blown cellulose insulation and panel insulation used on this wall that was facing the sun for most hours of the day and required additional attention to be properly insulated.  The existing wall panel insulation was insufficient and was not air sealed.  Our production team installed the SilverGlo insulation panels and used ZypFoam to seal up the cracks in between.  This helped to create the best result to help improve the comfort ii the home and reduce the energy costs related to heating and cooling the home.  

  • Ashburn VA Attic Hatch Platform and Insulation - Before Photo
    Before
    Ashburn VA Attic Hatch Platform and Insulation - After Photo
    After

    Ashburn VA Attic Hatch Platform and Insulation

    This Ashburn VA home had a need for a full attic insulation project.  The rooms in the home below the attic were uncomfortable, the attic was not air sealed and the existing insulation in the attic was not performing as needed.  Our Home Performance Sales Pro Jon recommended removal of the old insulation so that our production team could air seal the attic floor and then blow in Tru Soft cellulose insulation.  Additionally Jon added the production and building of an attic landing where the access hatch to the attic was.  This would allow for people to access the attic and stand on the platform with a barrier between the insulation.  A hatch cover was installed with a zipper seal to keep conditioned air from escaping the rooms in the living areas below the attic.   Our production team constructed this and helped to create a more comfortable home and more accessible attic for the home owners.  

  • Ashburn VA Attic Insulation, Air Sealing and Energy Reduction - Before Photo
    Before
    Ashburn VA Attic Insulation, Air Sealing and Energy Reduction - After Photo
    After

    Ashburn VA Attic Insulation, Air Sealing and Energy Reduction

    This Ashburn VA home was the recipient of a whole attic systems project.  Removal of old insulation, air sealing using Zyp Foam, foam paneling used to cover several HVAC exchange boxes and Tru Soft cellulose insulation blown in to to cover it all.  This will all help to reduce the energy cost it takes to heat and cool the home year round and make the home more comfortable for the owners. pictured here BEFORE is the attic with its original insulation and no air sealing below.  The AFTER photo shows the old insulation removed and Zyp Foam having been used to seal all of the gaps and cracks where conditioned air had been able to leak from the home below.  

  • Ashburn VA Attic Chimney Wrap and Insulation - Before Photo
    Before
    Ashburn VA Attic Chimney Wrap and Insulation - After Photo
    After

    Ashburn VA Attic Chimney Wrap and Insulation

    This Ashburn VA home was uncomfortable to the homeowners throughout different times of year.  They called us to see if we could help find a solution, which included a full attic project made up of air sealing, can light covers, insulation and having the chimney pipe wrapped and insulated with rock wool and spray foam.  

  • Ashburn VA Attic Wall Spray Foam - Before Photo
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    Ashburn VA Attic Wall Spray Foam - After Photo
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    Ashburn VA Attic Wall Spray Foam

    This Ashburn VA home had a room over its garage that shared walls with a partial section of the attic.  The homeowners called us to try and help make that room and other areas of the home more comfortable.  Our team air sealed the space with Zyp Foam before blowing in more Tru Soft cellulose insulation.  There was a small wall section of the attic with framing that created blocks of open space.  Our team used Spray Foam to insulate those blocks and finish the project.  

  • Spray Foam Garage Ceiling-Ashburn, VA - Before Photo
    Before
    Spray Foam Garage Ceiling-Ashburn, VA - After Photo
    After

    Spray Foam Garage Ceiling-Ashburn, VA

    This Ashburn, VA had rooms over the garage that were too hot in the summer.  This is can often be caused by fiberglass batts installed by the builder in the ceiling of the garage.  They fall away from the sub-flooring depleting all thermal insulating value.  This customer decided to remove the entire garage ceiling and use closed cell spray foam to fix the problem.

  • Ashburn VA Attic Wall Panel Insulation - Before Photo
    Before
    Ashburn VA Attic Wall Panel Insulation - After Photo
    After

    Ashburn VA Attic Wall Panel Insulation

    This home in Ashburn VA had several issues that the homeowner wanted to address, one of which was to make the upper level loft of the home more comfortable year round.  Our Home Performance Sales Pro Eric determined that this could be done by improving the insulation in the attic.  While the attic already had some blown in cellulose insulation covering the attic floor, the walls of the attic were poorly treated and were allowing cold temperatures and air to move into the space.  Eric suggested adding another 6 inches of insulation and to have Silver Glo panels installed on the walls of the attic.  The panels were then air sealed with Zyp Foam to properly protect the space from unwanted air flow.  

2020 #1 Dealer in the Network

2020 #1 Dealer in the Network

Inc. 5000 List

Inc. 5000 List

Loudoun County Chamber Small Business of the Year Award

Loudoun County Chamber Small Business of the Year Award

#1 Dealer in the Country for Dr. Energy Saver

#1 Dealer in the Country for Dr. Energy Saver

Loudoun's Favorite Insulation Company 2019

Loudoun's Favorite Insulation Company 2019

Best Picks 2019

Best Picks 2019

Best of Loudoun - 2019

Best of Loudoun - 2019

#2 Dr. Energy Saver Dealer in the Country

#2 Dr. Energy Saver Dealer in the Country

2018 Superior Service Business of the Year

2018 Superior Service Business of the Year

2018 Best of Loudoun Award

2018 Best of Loudoun Award

Entrepreneur Small Business Award

Entrepreneur Small Business Award

Angie's List Super Service Award

Angie's List Super Service Award

Best of Loudoun 2018

Best of Loudoun 2018

Dr. Energy Saver-#3 Dealer in North America

Dr. Energy Saver-#3 Dealer in North America

EBSCO Best Pick Report

EBSCO Best Pick Report

Innovative Business of the Year-2016

Innovative Business of the Year-2016

Loudoun Now-Favorite Insulation Company 2017

Loudoun Now-Favorite Insulation Company 2017

Service Business of the Year Finalist-2015

Service Business of the Year Finalist-2015

Comfenergy Grand Opening

Comfenergy Grand Opening

Entrepreneur of the Year-2015

Entrepreneur of the Year-2015