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Why use P-trap for condensate drain?

Jim Brown

Why use P-trap for condensate drain?

If fan is located before the coil in the system, the fan will push small amount of air and water down condensate drain. If fan is located upstream of coil, fan will pull water up drain line counter to water flowing down drain. A P-trap is needed to block air and allow condensate to drain properly.

Does an AC drain line need AP trap?

Your a/c system needs to have two drain lines. As you can see on the main drain line, there is a P-trap and the vent pipe is after the P-trap allowing for proper air and water flow. The secondary drain line needs to be pointing downward toward the drain pan, but other than that, it is properly installed.

Do I need a condensate trap if I have a condensate pump?

Without a trap, this doesn’t happen. If you have an air conditioning system with an indoor unit, or you use a high efficiency furnace, then you definitely need to have a condensate pump to remove the vapor and other condensate that will accumulate when the system runs.

How do you solve common problems with condensate traps?

Several common problems can occur in condensate drains, impairing their proper function….CAN YOU FIX IT YOURSELF? –

  1. Turn off your A/C, remove the cap of your drain.
  2. Flush the drain line with either vinegar, bleach, peroxide, or hot soapy water.
  3. Wait thirty minutes, then flush the line with water.

Where can I drain my condensate line?

You’ll find a white PVC or copper pipe located near your outdoor unit—this is where the drain line ends. Near your indoor unit, you’ll find a vertical PVC pipe with a cap on it, which acts as the access point for the condensate drain.

Where does the condensate trap need to be after the trap?

This vent is AFTER the trap and must remain open to be effective. The vent opening should always rise above the trip level of the condensate overflow switch when it is in the primary drain line or pan or above the secondary/aux overflow port on the primary drain pan.

Do you have to insulate a drain to prevent condensation?

But that excerpt really isn’t talking about condensate drains when read in context. Some municipalities do require that horizontal portions of the drain inside the structure be insulated to prevent condensation, and this standard makes sense to me.

How big does a condensate drain need to be?

IMC 307.2.2 tells us that an A/C condensate drain inside diameter should not be smaller than 3/4″ and should not be smaller than the drain pan outlet diameter. According to the IMC, 3/4″ is sufficient for up to 20 tons unless the drain outlet size is larger than 3/4″.

Where does the condensate from an evaporator come from?

Condensate comes from evaporator coil. If fan is located before the coil in the system, the fan will push small amount of air and water down condensate drain. If fan is located upstream of coil, fan will pull water up drain line counter to water flowing down drain.

Why use P trap for condensate drain?

Jim Brown

Why use P trap for condensate drain?

The primary purpose of the P-trap in a plumbing system is to form an isolation seal between that system and the sanitary sewer, thereby preventing sewer gases and other contaminants from entering the building. The drain seal on the condensate drain line of a draw-through hvac system has an entirely different purpose.

How do you drain a furnace?

How to drain central heating system

  1. Switch off the boiler.
  2. Shut off the water intake valve.
  3. Locate the drain-off valve and attach a hosepipe or place a bucket under it.
  4. Drain the radiators.
  5. Open the bleed valves to speed up the process.
  6. Complete the drainage process.

How deep should the condensate drain trap be?

If a unit were to be operating at minus 6 inches WC maximum negative plenum pressure then the trap height, per the guidelines shown in Figure 1a, requires 7 + 3½ + 1½ + 1 inches of height from under the floor or about 13 inches below the floor level.

How do you keep a condensate line from clogging?

You can prevent a clogged AC drain by performing routine cleaning. By pouring a ¼ cup of vinegar into your AC’s drain line, you will kill any mold, algae, mildew, and other forms of bacteria or fungi, preventing it from forming a buildup and causing a clog. Repeat this monthly for the best results.

Do you need a condensate trap in a gas furnace?

The condensate trap is absolutely mandatory for a high-efficiency gas furnace. Since the drain taps into the exhaust system, leaving it open to the air would allow for a potential exhaust/flue gas leak in the living space, which is a big no-no.

Do you need a trap for a HVAC system?

They simply state that drain systems must be trapped, leaving design to others. The traps like those shown in Figure 3 are available at many HVAC supply houses. They meet the codes and are often used in drain systems, regardless the drain pan pressure and type of air handler.

Is it OK to run a furnace drain under fresh air?

Avoid running the drain in an area where it could freeze. That includes running it under the natural fresh air inlet if there is one. Finally, note that furnace condensate is acidic, and some states/provinces/countries may require the condensate to be neutralized prior to draining.

Can a gas furnace drain be left open?

Since the drain taps into the exhaust system, leaving it open to the air would allow for a potential exhaust/flue gas leak in the living space, which is a big no-no. Additionally, the inducer motor would suck air through the drain if it weren’t trapped, which could affect combustion, and would prevent proper drainage.

Why use P-Trap for condensate drain?

Jim Brown

Why use P-Trap for condensate drain?

The primary purpose of the P-trap in a plumbing system is to form an isolation seal between that system and the sanitary sewer, thereby preventing sewer gases and other contaminants from entering the building. The drain seal on the condensate drain line of a draw-through hvac system has an entirely different purpose.

How does a condensate trap work?

Venturi steam traps operate by continuously removing condensate from the steam system. It allows any condensate present in the steam line to pass into the condensate return system as it is formed. The operation of the trap is based on the difference in density between water and steam.

Why do plumbers call it a P-Trap?

The piece of plumbing is also called a p-trap because the curve and the long extension that goes into the wall makes the part resemble the letter P. The reason for the plumbing trap is to create a barrier in the drainpipe that prevents sewer gas from rising back up through the drain and into the house.

Do I need a condensate trap if I have a condensate pump?

Without a trap, this doesn’t happen. If you have an air conditioning system with an indoor unit, or you use a high efficiency furnace, then you definitely need to have a condensate pump to remove the vapor and other condensate that will accumulate when the system runs.

Should condensate trap be full of water?

Your condensate trap is supposed to fill up with water if connected to outside or a drain, this stops odours etc coming into the property, when full the trap should let any condensation from the boiler run out to drain automatically.

How do you size a P trap?

To measure your P trap first locate locate it. It will be a U-shaped pipe connected to the straight pipe beneath your drain. Using a pipe wrench, unscrew the P trap’s connector and twist the P trap until you can slip a measuring tape across its opening. Then, make a note of this measurement.

Why are p traps used in air conditioners?

There are problems associated with the P-Trap when used in disposal systems, such as dry-out or freezing, but the benefits outweigh them. Since P-Traps seal against air leakage, they were the natural solution to prevent air leaking in the condensate drains of early 1900s air conditioning units.

What’s the difference between P traps and condensate removal?

The AC equipment is set on the slab, floor, or curb and it is the mechanical contractor’s job to install a P-Trap. There is a major difference between using P-Traps on sanitary applications and condensate removal from an AC unit and that is the latter has a pressure within the drain pain.

Is it necessary to have a plumbing trap on a condensate drain?

If fan is located before the coil in the system, the fan will push small amount of air and water down condensate drain. If fan is located upstream of coil, fan will pull water up drain line counter to water flowing down drain. A P-trap is needed to block air and allow condensate to drain properly.

What is the formula for a condensate trap?

CONDENSATE TRAPS H = Fan outlet pressure (in. W.C.) + 1/2 in. (minimum) Sea level with fan on Fan outlet pressure Recommendation: 1/2-in. minimum Condensate drain pan FIGURE 5. Trap for blow-thru unit, fan running and condensate beginning to drain away.