DIY Tips: How to Install an Air Supply Line and Cold Air Return to a HVAC

Learn all about your HVAC and how to install an air supply line and cold air return with this guide.


Things You’ll Need:

Understand Your HVAC

A HVAC works to heat your home in cool weather and cool it in warm weather. A fan works to draw air from the house through the system so that it can be either heated or cooled, depending on the room temperature. When the weather is cool, gas burners create heat within the heat exchange and this then heats the air that is circulating through the system. The warm air flows through the plenum and to the supply trunk line, where it is then distributed through the air vents through the home to heat rooms as needed.


When the weather is warm, cooling coils within the plenum cool the air flowing through the system before redistributing the cool air throughout the house.

Note: if you’ve added a new room to the property, you might need a load calculation to make sure that the furnace is big enough to supply the new room with the cool or warm air.

Attach the Takeoff to the Supply Line

  1. Check to see if you need a permit before embarking on any heating or cooling project.
  2. Using a pencil, mark the centre point of the takeoff and using the hole cutter and the cutting bit, drill a pilot hole.
  3. Next, pre-set the cutting bit so that it sits at the correct diameter to prevent cutting a hole of the wrong size. Put the centre guide into the pilot hole that you drilled earlier and then carefully start the cutting bit along the inside of the pilot hole to create a perfect circle. Using a right-angle drill will help here as the space that you’re working in is relatively small.
  4. Once the takeoff is set in place, pull the tabs over so that it will be fastened securely to the duct.


Install the Ceiling Register Boot and Cut the Supply Duct

  1. Put the ceiling register boot between the floor joists and screw into place using the power nut driver and the self-tapping screws. Measure from 1 inch into the takeoff to 1 inch into the boot collar to work out how much supply duct you’ll need to cut, then cut it to length using the round duct cutter.
  2. Fit the duct together and snap into place.

Install and Secure the Damper

  1. Making sure that you’re installing the damper to the bottom of the duct, install it by drilling a hole into the side of the duct and then screw the damper into place onto the duct. Put the crimped end of it in first and then put the other end of the duct in – the takeoff will rotate, allowing you to get a tight and secure fit.
  2. Secure both ends of the damper and ducts by screwing sheet metal screws into the collar.

Add the Register and the Support Brackets

  1. Add support brackets to keep everything in place along with the register to finish the job.

Install the Cold Air Return

For the furnace to work properly, the air needs to be recirculated through the system and so that is why a cold air return needs to be installed.

  1. Nail a piece of sheet metal onto the back of the stud cavity and cut one hole in the stud cavity and another in the existing cold air return.
  2. Secure start collars through both of the holes and then use the non-insulated, flexible duct to connect the two holes. Secure the duct in place with the plastic cable ties.


Source: DIY Network

DIY Tips: How to Build a Screen to Conceal the Air Conditioning Unit

Learn how to disguise the ugly outdoor air conditioning unit by building this unique and pretty cedar screen.

Things You’ll Need:

Build the Frames


Build two very simple frames using the 1 x 4 planks and the nailer and nails. Each frame should be 44” tall and 42” wide.

Attach the Cedar Boards


Use the pneumatic stapler to attach the cedar boards to the frame to create the screen. You can attach the boards in a straight fashion or in an overlapping fashion, whichever you prefer. You might also prefer to use green oak or another weather resistant wood, instead of cedar, according to the décor of your home.

Make the Screen

Drill pilot holes using the drill to create holes for you to put the hinges through so that you can attach the two sides of the screen. Attach the hinges with screws and then attach the cane bolts at the bottom of the screen with the mounting bracket and screws that will come supplied with the cane bolts. Wrought iron hinges look particularly lovely in a traditional property, although you might prefer to use new, modern stainless steel hinges.

Set the Screen in Place


Unfold the screen and set in place next to the air conditioning unit using the cane bolts.

Source: DIY Network

DIY Tips: How to Replace Old Air Conditioning Ductwork and Install a Return Vent


Learn how to replace old and potentially smelly air conditioning ductwork and install a return vent to keep your air conditioning system in tip-top condition.

You’ll Need:

• new metal vent and flexible air duct
• nails and screws
duct tape
• aluminium tape
• 2 x 4 boards
• plastic rib
• insulated duct board
• mastic adhesive cement
• plastic ties
measuring tape
• scissors
cordless drill
• paintbrush

1. Remove Old Ductwork and Install New Air Duct

Remove the Ductwork

Remove the old ductwork where needed – any ductwork that is damaged, broken, rotten or excessively dirty should be replaced if it cannot be fixed or cleaned. Install the new air duct by running the new flexible air duct underneath the house from the floor return to underneath the air handler. Attach it to the vent box or to the plenum.

2. Add Extra Length

If the air duct isn’t long enough, you can use two ducts fitted together. Peel back the insulation and tuck it into the first section of air duct by about 10 inches. Seal using duct tape.

3. Attach the Duct to the Floor Joists

Remove the Ductwork2

Using the plastic ties, attach the air duct to the floor joists every few feet to keep it away from the ground.

4. Seal the New Duct

Secure and Seal Duct

Using the plastic ties, seal the new duct to the new box, ensuring that the connection is tight to prevent leaks. Once the connection is in place, clip the plastic ties and seal with the aluminium tape and burnish with one final plastic tie.

5. Create a Wooden Frame to Hold the New Vent

Create a Wooden Frame

If the new vent is a different size to the old one, you may need to create a wooden frame to hold it in place. Measure the opening for the vent and cut the boards to size. Nail the boards together to create the framework, place into the vent hold and nail into place. Sit the new vent into the frame, centre the frame by using extra 2×4 boards to brace it and then nail the vent into place.

6. Fill in the Gaps

Create a Wooden Frame2

Use the insulated duct boards to fill in the gaps between the new vent and the framework. Ensure that the board fits snugly, and if needed, further insulate the vent with the mastic adhesive cement. Use the paintbrush to brush the cement into any gaps and ensure that it is completely dry before covering.


Source: DYINetwork

DIY Topics: How to Install a UV Purifier

A UV purifier is an excellent way to reduce dust within the home, so learn how to install a UV purifier to the air handler unit in the home with this simple step-by-step guide.

Things You’ll Need:

UV purifier
• safety goggles
• hole saw bit
• gloves

Choose the Placement of the Light


1. Before getting started, refer to the manufacturer’s instructions for more detailed information.
2. Choose the placement of the bulb. Ensure that it has plenty of clearance.
3. Put the self-adhesive template in place and then drill the 2 1/4” holes according to the template.

Connect the UV Bulbs

Connect the UV Bulbs

1. Using the drill and the hole saw bit, drill two holes into the metal ductwork of the air handler. Using the template, drill holes for the back plate too. Be sure to grip the drill very firmly before turning it on.
2. Connect the UV bulbs, but be sure not to touch them with your bare hands – use gloves as this will prevent the oils from your hands from damaging the bulb. Ensure that you refer to the manufacturer’s instructions during each and every step.

Install the Back Plate and Test the UV Purifier


1. Install the back plate onto the unit and drill into place.
2. Secure the bulbs, ensuring that there is enough clearance around each bulb.
3. Connect the power to the unit and test the UV purifier, making sure that the bulbs work properly.

Remember to change the bulbs annually.


source DIYNetwork

DIY Tips: How to Ensure Clean Air at Home

The air inside your home can actually be more polluted than the air outside your home – so follow the tips below to learn how to keep the air within your home clean and pollutant-free.

Make Lifestyle Changes

No Smoking Policy

1. Smoking will cause major issues when it comes to the air inside your home as the second and third-hand smoke that sticks to surfaces can become carcinogenic. To ensure clean, safe air within the home, enforce a no-smoking policy.

2. Get rid of mouldy carpets or furnishings such as curtains or cushions. Mould spores can not only give off a nasty, musty smell, but they could even cause respiration problems. If you find damp patches or mould patches on walls, fix the damp by treating the area with a damp course solution.

3. Repair water leaks, if any. Leaking water through ceilings or through cracks in the can cause damp patches and mould, so repair all water leaks and treat the areas as required.

4. Fit a cooker hood, if you don’t have one, to vent cooking smells and odours outside.

5. Vacuum the home regularly. This will cut down on dust and dust mites and should make the home more allergen-free. If anyone in your house suffers particularly badly with allergies, it might be a good idea to switch carpets for laminate or wooden flooring and to remove soft furnishings that dust and dust mites could cling to.

6. Keep doors and windows open to allow fresh air from outside to flow throughout the house.

Install an Air Filtration System

Install a Filtration System

Another alternative that will ensure clean, fresh air every day is to install an air filtration system. A whole-house air filtration system with a minimum efficiency reporting value of at least 16 will remove up to 95% of the mould, spores and dirt from the air. It can also remove pet debris, pollen and fungi and it could even remove viruses and bacteria. A professional should install the MERV system.

Prevent Mould Growth on the AC Unit

Reduce Mold Growth on the AC Unit

Finally, preventing mould from growing on the AC unit is another way to keep the air within your home clean and pollutant-free. You can reduce mould within the AC unit by using air filters and by using a portable ozone-free room cleaner. You could also use a UVC germicidal light which will help to reduce mould spores.


source: DIYnetwork

DIY Tips: What You Need to Know About Air Conditioning

Enjoying every room in your house can be a little difficult when the temperature rises, but choose an efficient air conditioning unit and your energy bills will stay cool whilst you do too.

air conditioning

Air conditioning is just one part of an air conditioning unit. Most air conditioning units can also heat and ventilate the home and are called HVAC systems, or heating, ventilating and air conditioning systems. The air conditioning unit itself – the cooling part – typically sits outside the home. Liquid refrigerant, what keeps the air conditioning unit cool, is pumped into the air handling unit, which is the unit that generates hot or cool air. The AHU then then forces the cool or warm air out into the rooms through a series of supply ducts. Once the liquid refrigerant has circulated through the whole unit, it travels back through supply ducts and tubes to the air conditioning unit so that it can be cooled and then recirculated back through the unit.

Air Conditioning Best Practises

No matter how efficient the unit, or how high the SEER rating, if the unit and the placement of it has not been planned properly the unit may not run as well as it could. The supply ducts play an important part in this process as if they are positioned incorrectly, cool air might not reach the right places within the home – rendering the unit pretty ineffective.

When fitting the air conditioning unit, the HVAC engineer should do some engineering calculations to ensure that the ducts and vents selected for each room are the right size for the shape and purpose of the room. Dampers should also be installed where necessary to ensure proper air flow in each room. The location of the vents and the size of the vents within each room should differ depending on the size of the room and the local climate. Hot areas might do better with the vents located high on the wall, while cool areas that will use the HVAC system mostly for heating might do better with the vents placed low on the wall.

Another important factor in how effective the system is is the location and the tightness of the ducts. A special sealant should be used around all joints to prevent air from leaking out before it reaches the right rooms. Leaks can also cause air from outside the system to mix with the cooling air within the unit, meaning that the air coming from the unit is warm rather than cool. Ideally, ducts should be located beneath the inside the insulation layer of the house so that they aren’t exposed to exterior temperatures.

Before purchasing a unit or installing one into your home, you need to double check the SEER rating of the system, whether the ducts are sealed with the correct sealant as according to local government guidelines, the location and the size of the vents and ducts. Ask a HVAC engineer about anything you don’t understand or if you have any questions.

DIY Tips: How to Tune Up Your Furnace

Tuning up your furnace should be left to the professionals. Below are some of the steps that may be undertaken during a furnace tune-up.

1. Visual Inspection

Visual Inspection

Firstly, the professional will set the furnace to heat and the thermostat will be turned up. The fuel-jets will also be checked to make sure that the furnace is burning fuel properly. The power supply and fuel supply will then be switched off while the professional checks over the venting system, which removes unsafe flue gases.

Visual Inspection2

The venting ducts will be checked over to ensure that they are well sealed, while the joints will be checked over to ensure that they are sealed using three metal screws.

2. Check Over the Filter

Remove the Covers and Check the Filter2

The cover of the furnace will then be removed, along with the blower compartment, so that the professional can look over the mechanical parts of the furnace as well as the filter. The filter may need to be replaced or reinstalled so that the air flow indicator is pointed towards the furnace.

3. Check the Blower

Check the Blower

Flashlights and mirrors will be used to enable the professional to check over the inside of the blower for any obstructions or damage. If necessary, the furnace will be lubricated.

4. Remove the Burners and Check the Furnace Chamber

Remove and Clean the Burners

The burners will then be removed from the furnace so that they can be cleaned but also so that the professional has better access to the furnace chamber. The chamber will then be inspected for any defects, such as rust, erosion, holes, separated seams or debris.

Remove and Clean the Burners3

The burners will be cleaned with water to remove any dirt or debris and the sensor and pilot will also be cleaned to ensure that they continue to run effectively and efficiently.

Reassemble the Components

The components will then be put back into the furnace.

5. Safety Tests

Perform Safety Tests

The professional will then perform safety tests to ensure that the furnace is running safely.

Perform Safety Tests2

The highest limit on the furnace will be checked over to ensure that it won’t overheat, the gas meter will be looked over to check how quickly fuel is being used and the flue will be checked for carbon monoxide using a carbon monoxide meter.

Perform Safety Tests3


• It’s recommended that you purchase a carbon monoxide meter to alert you and your family in case of high carbon monoxide levels within the home.

• Keep the area around the furnace clean and unobstructed.



Source: DIYNetwork