DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   HVAC (
-   -   Intake vent for electric dryer // house too tight? (

curls00 12-15-2010 10:07 AM

Intake vent for electric dryer // house too tight?
I'm in the process of having a tankless water heater install figured out, and due to some tight clearances to stay within code, I will need to convert my NG furnace to a direct-vent by using the existing tank water heater exhaust pipe as a fresh-air intake connected directly to the furnace, and use the existing fresh air intake hole as the combination intake/exhaust for the NG tankless water heater.

Now, this will make the combustion appliances fall within code - great. However, it occurred to me that the electric dryer will not have a source of fresh air to use, potentially causing a vacuum in the house. Is this a concern? Will not having a fresh air intake near the electric dryer cause potential problems with efficiency of the dryer, or with leaks forming in the rest of the house?

House is 8 years old, fairly tight (updated weatherstripping on doors, windows don't leak).

Should I be concerned or should I go ahead as planned?


yuri 12-15-2010 04:13 PM

I would not be worried about it unless you run the clothes dryer, kitchen exhaust fan, central vacuum system and bathroom exhaust fans at the same time and suck lots of air out. One appliance won't draw that much air and even if it does air will suck back in thru the kitchen exhaust or bathroom exhaust fans. Their backdraft dampers don't seal very tight. The furnace and water heater have pressure switches to prove enough air for combustion. Try run the clothes dryer for 10 mins and see how hard it is to open your front door if you are worried.

curls00 12-15-2010 05:19 PM


Originally Posted by yuri (Post 551657)
Try run the clothes dryer for 10 mins and see how hard it is to open your front door if you are worried.

Good idea -- I'll put a plastic bag over the fresh air intake pipe and on the furnace intake pipe (so it doesn't draw through the exhaust). Start the dryer and see how it goes. Thanks a lot!

yuri 12-15-2010 05:26 PM

We are extending our longest skating rink on the Red River this year so your Rideau Canal may be the poorer sister. LOL :laughing:

Know It ALL 12-15-2010 06:16 PM

Good question curls00. If your home was so tight that no air could enter or exit you would feel the change of air pressure inside of your ears when you closed an exit door.
I suggest a homemade barometer to monitor your inside air pressure. Very simple to make. I take a large mouth clear glass jar of at least one quart size and fill it half full of water. The next clear glass container might be a little harder to find. It needs to have a long slender neck with a storage capacity of 6-12 oz. sort of like a rose vase. Simply set the vase inside the jar of water and observe. There are dozens of ways to make a barometer.

All times are GMT -5. The time now is 01:48 AM.

User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.