Which AC lines should be insulated?

A typical residential AC unit has two copper lines that both exit the building exterior and run to the outside condenser unit. Only one of these copper pipes, the cold line, should be insulated. This is called the “suction” pipe and is typically the larger of the two pipes.

What happens if AC pipe is not insulated?





If the return line is not insulated, the refrigerant returning from evaporator to the compressor will absorb some heat, more heat than it had at the outlet of the evaporator. This extra heat will also be present in the compressed refrigerant going to the condenser, downstream of the compressor.

Does outside air need to be insulated?

In general, the entire surface of outdoor, supply and exit air ducts should be thermally insulated along the whole length of the duct. Exhaust air ducts should also be insulated – in buildings to provide noise control and outside buildings to prevent condensation.

How do I insulate my central air conditioner?

Quote from the video:
Quote from Youtube video: But you also want to make sure the covers and seals the entire line I start by trimming the end as needed to fit snugly against the house.

How do you insulate outside AC lines?

Quote from the video:
Quote from Youtube video: So that the compressor can cool down. So just kind of fit it over there like that and I strip the old insulation off already. So you get it to a comfortable length where you're happy with it.

Do both refrigerant lines need insulation?





You typically don’t need to insulate the high-pressure refrigerant line. You should, however, insulate the low-pressure refrigerant. Insulating the low-pressure refrigerant line will protect against condensation.

Do HVAC return ducts need to be insulated?

In fact, without proper insulation, you can be losing up to 30% of the energy that is used to heat or cool your house. Tip: to find out if your ductwork needs additional insulation, place your hand close to the supply register. The answer is ‘yes’, in case the air feels lukewarm.

Should AC drain lines be insulated?

No. Building & mechanical codes do not require insulation on A/C condensate drains, based on a reading of the current U.S. Energy Code that I will excerpt here.

Can fiberglass insulation touch ductwork?

Fiberglass insulation can touch HVAC ductwork provided the ducts are not leaking or forming too much condensation. The insulation should be snug enough to prevent significant gaps throughout the ductwork.

How much does AC pipe insulation cost?



Average Cost of Plumbing Insulation

Average Cost $600
High Cost $1,100
Low Cost $110


How do you insulate an AC condensate pipe?

Quote from the video:
Quote from Youtube video: So this will prevent the condensate from forming on the pipe due to the cold water flowing through the pipe a condensate dripping down onto the floor and then destroying the ceiling. Below.

How can I prevent my HVAC condensate drain line from freezing?



Can you prevent HVAC condensate drain lines from freezing?

  1. Insulate drain with a weatherproof material.
  2. Use Ice Melt underneath the drain line exit point.
  3. Install heat tape around the exposed pipe.


Why does my condensate pipe keep freezing?

A condensing boiler turns the hot exhaust gases into water via a heat exchanger. This reclaims 20% of the heat energy. This water is taken out of the property through a plastic condensate pipe which can be prone to freezing when temperatures are below freezing.

Can you run a condensate pipe into a waste pipe?

Yes, a condensate pipe can be routed into a waste pipe. This is best done after the trap on the waste pipe in case of blockages.