Evaporator coil drier for A/C

ICanHas · 08-15-14, 11:26 PM

Anyone tried setting one up? The coil itself holds about a pound of water per ton of cooling capacity and once it builds up to this capacity, further condensation is drained down the pipe.

As you get into evening hours and AC no longer needs to run, the water just evaporates back out into the conditioned space not to mention keeping everything inside the ducting very humid.

A simple setup that can air circulate outdoor air just within the air handler would avoid the problems associated with coil being wet all night long at room temperature as well as re-evaporation such as mold and bacteria growth in the AHU.

it would be easy to implement on a package unit, but needs a two pipe dryer vent like setup for a split unit.

Thoughts?

NiHaoMike · 08-15-14, 11:35 PM

Main challenge is to keep the conditioned air from leaking outdoors (or vice versa) when the A/C is in use. Other than that, it does sound like a good solution.

Servicetech · 08-16-14, 08:45 PM

In the evenings the outdoor air is typically very humid. No sure how much coil drying would happen during the off cycle. A better solution is use the smallest system that will do the job. Smaller coil = less water held. Cycles are also longer helping reduce humidity in the house. Drawback is the system may not hold indoor setpoint when outdoor temps exceed 95f.

ICanHas · 08-16-14, 11:27 PM

During shoulder seasons, a forced outdoor air ventilation through the evaporator using dampers could help with microbial growth at the coil.

I always dry the coil out as much as I can in my car by running the fan the last 5-10 minutes of driving if i'm going to be parking all day or all night. Haven't got stank air ever since.

Servicetech · 08-17-14, 09:29 AM

During shoulder seasons a residential economizer (aka open the return air to the outside for cooling) would dry the coil between cycles.

08-15-14, 11:26 PM	#1
ICanHas Banned Join Date: Aug 2014 Location: US Posts: 150 Thanks: 7 Thanked 5 Times in 5 Posts	Evaporator coil drier for A/C Anyone tried setting one up? The coil itself holds about a pound of water per ton of cooling capacity and once it builds up to this capacity, further condensation is drained down the pipe. As you get into evening hours and AC no longer needs to run, the water just evaporates back out into the conditioned space not to mention keeping everything inside the ducting very humid. A simple setup that can air circulate outdoor air just within the air handler would avoid the problems associated with coil being wet all night long at room temperature as well as re-evaporation such as mold and bacteria growth in the AHU. it would be easy to implement on a package unit, but needs a two pipe dryer vent like setup for a split unit. Thoughts?

08-15-14, 11:35 PM	#2
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Main challenge is to keep the conditioned air from leaking outdoors (or vice versa) when the A/C is in use. Other than that, it does sound like a good solution. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

08-16-14, 08:45 PM	#3
Servicetech Apprentice EcoRenovator Join Date: Nov 2013 Location: Moore Oklahoma Posts: 267 Thanks: 108 Thanked 23 Times in 21 Posts	In the evenings the outdoor air is typically very humid. No sure how much coil drying would happen during the off cycle. A better solution is use the smallest system that will do the job. Smaller coil = less water held. Cycles are also longer helping reduce humidity in the house. Drawback is the system may not hold indoor setpoint when outdoor temps exceed 95f.

08-16-14, 11:27 PM	#4
ICanHas Banned Join Date: Aug 2014 Location: US Posts: 150 Thanks: 7 Thanked 5 Times in 5 Posts	During shoulder seasons, a forced outdoor air ventilation through the evaporator using dampers could help with microbial growth at the coil. I always dry the coil out as much as I can in my car by running the fan the last 5-10 minutes of driving if i'm going to be parking all day or all night. Haven't got stank air ever since.

08-17-14, 09:29 AM	#5
Servicetech Apprentice EcoRenovator Join Date: Nov 2013 Location: Moore Oklahoma Posts: 267 Thanks: 108 Thanked 23 Times in 21 Posts	During shoulder seasons a residential economizer (aka open the return air to the outside for cooling) would dry the coil between cycles.