HVAC Contractor in Los Angeles

Maingreen Remodel & Construction is an HVAC contractor in Los Angeles: we can update, repair or replace all brands and models, and replace old systems with new, energy efficient ones.

We can update, repair or replace all brands and models!

  • create a more temperature comfortable home
  • save money on your heating and cooling bills
  • benefit the environment by replacing your old system with a new, energy efficient one
  • release you from a future of expensive repair services
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HVAC Services

A smart HVAC system will do wonders for your home and your wallet. When people think about heating and air conditioning, the first thing that comes to mind is high bills, and some put that fear above their own comfort. At Maingreen Remodel & Construction we want to help you keep your electric bills low and breathe cleaner air.

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Repair or replace your heating and air conditioning?

A repair is the sensible call on a system that is young and otherwise healthy. ENERGY STAR suggests it may be time to look at a replacement when:

  • the air conditioner or heat pump is more than 10 years old, or the furnace more than 15;
  • repairs keep coming and the energy bills keep climbing;
  • some rooms stay too hot or too cold;
  • the air is too humid in summer or too dry in winter, or dust builds up fast;
  • the system is noisy, which can point to undersized ducts or a problem with the indoor coil.
Roofing in Santa Ana: an old, rusted rooftop cooling unit on the flat roof

What a yearly check-up should cover

ENERGY STAR recommends a pre-season check-up every year: the cooling side in spring, the heating side in fall. Whoever services your system, the visit should include:

Van Nuys job with mold remediation, roofing and HVAC work: crew at the rooftop HVAC unit

  • Coils, refrigerant and airflow

    Clean coils, a refrigerant level checked and adjusted, and blower parts cleaned. ENERGY STAR notes airflow problems can cut efficiency by up to 15 percent.

  • The condensate drain

    A plugged drain can cause water damage in the house and throw off indoor humidity.

  • Gas, burner and heat exchanger

    A dirty burner or a cracked heat exchanger makes a furnace run less safely and less efficiently.

Residential HVAC remodels: plan the air with the rooms

Moving walls, adding a room or opening a ceiling changes how heated and cooled air has to reach each space. That is why HVAC is planned with the remodel, while the walls and ceilings are open, rather than fitted in afterwards.

ADU and additions in Sherman Oaks: floor plan of the planned addition with the ADU, a bedroom and a bathroom

  • An addition or an ADU

    The heating and cooling loads are calculated for the new space; the Energy Code accepts the ASHRAE, SMACNA or ACCA Manual J methods. An ADU, as a new dwelling unit, gets whole-house mechanical ventilation at any size, and so does an addition that grows the home by more than 1,000 square feet.

  • A new kitchen or bathroom layout

    Supply registers and returns move to suit the new plan, and ducts are routed where cabinets, soffits and framing leave room.

  • Attic and ceiling work

    With the attic open, the ducts can be sealed and insulated and the attic brought up to code at the same time. See insulation.

  • A heat pump in place of a furnace

    A heat pump heats and cools from one system. It runs on electricity, so the electrical panel and a dedicated circuit are checked first, part of an electrical upgrade when the panel is full.

Eco friendly HVAC for comfort

Maingreen Remodel & Construction can help you get the best HVAC upgrade for your home.

Maingreen Remodel & Construction is here to help you with all your remodeling needs. Upgrade your HVAC today, reduce your carbon footprint and start saving money!

Protect the environment

Updating your HVAC system pads your wallet and benefits the environment!

Less noise

Create a quieter space to work and relax at home.

Tax incentives

Enjoy tax breaks for your eco-friendly upgrades.

Comfort and control

Increase your home’s comfort by creating a temperature controlled environment.

Replacing an AC, heat pump or furnace in Los Angeles: what the Energy Code requires

California's 2025 Energy Code (Title 24, Part 6) applies to permit applications made on or after January 1, 2026, and it treats a change-out of equipment as an alteration with checks of its own. The ones homeowners meet most often, from Section 150.2(b)1:

Mold remediation in Van Nuys: a ceiling opened up to the joists, with an air duct running above

  • New equipment, existing ducts

    Replacing the air handler, the outdoor unit of a split system or a coil means the connected ducts are sealed and tested: leakage at or under 10 percent of the system's airflow, or 7 percent to the outside. Where neither can be met, every accessible leak is sealed and checked by a certified ECC-Rater with a visual inspection and a smoke test.

  • When the duct test is not required

    Duct systems under 40 linear feet, ducts already sealed and tested under these procedures, and ducts built, insulated or sealed with asbestos.

  • A new duct system

    Leakage at or under 5 percent of airflow. Ducts in an attic, crawlspace or other unconditioned space are insulated to R-6 in climate zone 6 (the coast) and R-8 in zones 8, 9 and 14.

  • Work on the refrigerant side

    Thermostats are replaced with setback thermostats. Air conditioners in zones 8, 9 and 14 (not zone 6), and heat pumps in every zone, also get their airflow and refrigerant charge verified in the field. A new packaged unit charged at the factory skips the field charge check; its airflow is still verified.

Full remodel in Thousand Oaks: bedroom with an air register high on the wall above the door, and recessed lights
Van Nuys job with mold remediation, roofing and HVAC work: the roof from above, with the rooftop HVAC unit beside the solar panels

Check Out Some Of Our Latest Projects

What sets the price of HVAC installation

  • The system

    A split AC with a furnace, a heat pump, a packaged unit or ductless mini-splits, and the efficiency level you choose.

  • The ducts

    Reusing and sealing the existing ducts, or a new duct system; old ducts that contain asbestos change the plan.

  • Where it goes

    Attic, closet, crawlspace, roof or garage, and how easy each is to reach. Ducts and equipment in a garage have their own sealing rule.

  • Electrical and testing

    A new circuit or panel work for the new equipment, the permit and the field verification the code calls for.

The in-home assessment and estimate are free. HVAC work often goes in with a home remodel or an ADU, while the ceilings and walls are open.

Get a free HVAC estimate
Full remodel in Thousand Oaks: bedroom with an air register above the door, recessed lights and a new bathroom beyond

How does it work?

The Maingreen Remodel & Construction HVAC Services

Step 1 – You call us now to set up your FREE in home assessment and estimate.

Step 2 – One of our team members will show you the best options for your home’s specific needs.

Step 3 – Our expert installation teams begin work right away.

Step 4 – We make sure YOU are happy with your new HVAC and all the functionalities and money saving perks that come with it.

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Rest Assured. Working with us is a GREAT decision.

With hundreds of happy customers, we know you will be satisfied with our work, our friendliness and our attention to detail. We are dedicated to making your dream home remodel a positive experience.

FREE CONSULTATIONS

We offer free energy efficient consultations with one of our certified experts. We come to you at your earliest convenience.

HONESTY

We value honesty in life and business.

LICENSED

Maingreen Remodel & Construction is licensed and insured.

PROTECTION

With rising energy costs, we can help you protect your spending and increase the value of your home.

TRANSPARENCY

We work with you every step of the way. We provide clear outlines on the scope of work necessary to meet your dream.

ADU and additions in Inglewood: the addition framed in wood, with the old concrete broken up in the yard

HVAC questions

Which HVAC brands do you work on?

All of them. We can update, repair or replace all brands and models, and replace old systems with new, energy efficient ones.

Should I repair or replace my air conditioner?

ENERGY STAR suggests considering a replacement when an air conditioner or heat pump is more than 10 years old (a furnace, more than 15), when repairs keep coming and bills keep rising, or when some rooms never get comfortable. A system that is younger and otherwise healthy is usually worth repairing.

Does replacing an AC in Los Angeles require a duct test?

Usually, yes. Under California's 2025 Energy Code, replacing the air handler, the outdoor unit of a split system or a coil means the connected ducts are sealed and tested. Duct systems under 40 linear feet, ducts already tested under these procedures and ducts containing asbestos are exempt.

Can you add or move HVAC as part of a remodel or addition?

Yes. In a residential HVAC remodel the heating and cooling are planned with the new layout: loads calculated for the new space, ducts and registers routed while walls and ceilings are open, and the electrical service checked for new equipment.

How often should a central air system be serviced?

Once a year before each season, according to ENERGY STAR: the cooling side in spring and the heating side in fall. Check the air filter every month in between and change it when it is dirty.

How much does HVAC installation cost in Los Angeles?

It depends on the type of system, whether the existing ducts can be reused and sealed, where the equipment sits, any electrical work the new equipment needs, and the testing the Energy Code requires. The in-home assessment and estimate are free.