Welcome to Diligent

We are passionate about clean air, clean water and power saving!

Diligent is defined as: Marked by persevering, painstaking effort; Constant in study or effort to accomplish what is undertaken; attentive and persistent in doing anything; industrious

Diligent was started on the premise of providing our customers honest and quality service. We understand the needs of our customers and we go a step further by helping them get an understanding of their home systems. Our technicians will guide you step by step through the service being provided, how the units work and ways to help increase energy savings and efficiency. With over 20 years in the industry, we are confident that we can meet and exceed your needs.

With these ever-changing times, Diligent has partnered with industry leaders in Air purification and water filtration. We will continue to expand to become the leader in residential and commercial clean air solutions, purified water, and power saving.

Let me be the first to thank you for your business, take a look around the rest of the site, and check the testimonials. When you are ready, send us a message and one of our highly trained staff will be in touch.

Get free consultation!

We will answer all your questions and help you make smart decisions that will save you money and help the earth
Limited time offer
We are Industry leaders at...


Air Conditioning

Great air conditioning Service, Repair, and Install in the 5 Boros, Nassau and Suffolk County, New York


Furnace and heater service needs, from minor maintenance and repairs to full heating system installations and heater replacements.

Indoor Air Quality

Indoor Air Quality (IAQ) refers to the air quality within and around buildings and structures, we offer indoor air quality audits that help you stay safe.

Clean Air Solutions

With the recent outbreak of Covid19, Diligent offers high pressure steam cleaning of your Air system coils. Based on reports from the CDC this method is chemically free and will rid your system of viruses, mold spores and bacteria along with removing the dirt and debris that can naturally build up on coils. This will make the air you breathe healthier and increase the efficiency of your HVAC System.

Purified Water

We provide top-of-the-line, highly trained individuals, and technology-driven systems that ensure reliable and efficient multi-layered Water Filtration.

Power Savings

Diligent offers energy audits. Energy audits have been increasing in popularity among residential and commercial facilities. Learn how to save on your electric bill.

High level of competence

Our experience will help you create a quality product

Diligent HVAC prides ourselves in staying current with HVAC technologies that are constantly evolving and getting better with more and more focus on energy savings. 

Air Conditioning
20 years
10 years
Clean air
5 years
Water purification
10 years

Diligent is committed to be your source for an living and working environment that is comfortable, free of impurities, environmentally conscious and most importantly cost saving.

Let me be the first to thank you for your business, take a look around the rest of the site, and check the testimonials. When you are ready, send us a message and one of our highly trained staff will be in touch.


President Patience HVAC LLC dba Digilent


Great Quality Service is our priority

Expert Technician

Our technicians are experts with an average of 20 years experience in the HVAC trade.

On Time Every Time

We know your time is valuble and we make sure to be on time for your scheduled appointment.

24/7 support

Diligent supports your HVAC systems 24/7! We will come and get your air conditioner or heater back online fast!

Principles of our work

Honesty & Integrity are the cornerstone of our business

Diligent will tell you the truth and never try to sell you something you don’t need. 

Our reputation has been carefully nurtured with honesty and integrity being the most important element of our business.

The Diligent process includes total transparency, we show you what we’re doing and why we’re doing it.

One of our main goals is to help our clients save money! From energy audits to system efficiency Diligent implements money saving solutions. 

Free consultation

Quick clean air and water audits

Diligent will test your indoor air and water quality and you will have information to make smart choices.

Quick start

Follow these 3 easy steps to start our partnership!




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Schedule an Appointment


Do It Yourself TIPS

Check Filter

Check the air filter in your furnace or fan coil each month. A dirty filter will cause excessive wear on your furnace, air conditioner or heat pump. Replace your filter when necessary, or clean it if you have the reusable type. (If you have a reusable filter, make sure it’s completely dry before you re-install it.)

Remove Debris

Keep your outdoor condensing unit free of debris. If you keep grass clippings, leaves, shrubbery and debris away from your outdoor unit, it should only require minimal care. Check the base pan (under the unit) occasionally and remove debris, to help the unit drain properly.

Brush Exterior

If the exterior of your outdoor coil becomes dirty, use a brush or a vacuum cleaner with a soft brush attachment to clean the surface. To clean dirt that is deep in the coil, contact a Brody-Pennell representative to schedule maintenance.

Check Level

Make sure your outdoor coil stays in a level position. If the support for your outdoor coil shifts or settles and the unit is no longer level, re-level it to make sure moisture drains properly out from under the unit.

Inspect Ventilation

Inspect your furnace’s combustion area and vent system before each heating season. If you find dirt, soot or rust, your system may not operate properly or at its peak efficiency. Call Brody-Pennell and do not operate your furnace until it is professionally inspected and/or repaired.

Clean Air Cleaner

The pre-filter and collection cells of an electronic air cleaner should be cleaned at least two or three times per year.

Anthony was awesome! He was a true professional and knew his job. He was pleasant and friendly. I will definitely recommend him and company

Raymond K.

He was Honest, Clean, Efficient and i would highly recommend him! He was very good and very trustworthy!

John M.

He is very nice and comes out when he says he will. He is very professional and gets the job done. I would highly recommend him, He knows what he’s doing!

Christine C.
Contact info

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Areas of Service

the 5 Boros, Nassau and Suffolk County, New York

Business hours

  • Monday 8 am - 6 pm
  • Tuesday 8 am - 6 pm
  • Wednesday 8 am - 6 pm
  • Thursday 8 am - 6 pm
  • Friday 8 am - 6 pm
  • Saturday 8 am - 6 pm
  • Sunday Closed