Pros, do y'all close a supply or two in your own home?
WE have a new HP installed and its blowing a *****in' gale into the mudroom.
I shut the vent down into that particular room.
I'll open it if its gonna harm the overall performance
Personally I leave all supplies open in my own home. None receive too much air. Better solution for your mudroom is for a balancing damper to be installed on the duct that feeds that supply vent. Damper should be installed near trunk line or plenum feeding mudroom supply vent ducting, not right at the supply vent connection.
Often, when the dampers are throttled closed on a supply vent that feeds too much air, the vent will whistle or give off annoying white noise, which is undesirable. Better to control the amount of air going to that vent at a better location.
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.
Mudrooms should only get enough air to temper them. If they have a door that can isolate them from the rest of the house, and no return in them.
Although all my registers are open.
The closing of one register is ok, on any system that has adequate air flow for the system.
But, its usually better to just balance the system, or throttle down a register in a room you don't need conditioned to normal temp.
Outside walls have better insulation then inside walls. So you would acutally have more heat loss (or gain) if a inside room was the same temp as outside. You can adjust the supply vent so you don't get to much air but i would not shut it off.
All vents open.
I found that standard residential supply registers are difficult to use for balancing. You'll have much better results paying an installer to add dampers to each supply branch. It's likely the mudroom is located on a section of the main supply trunk that has more restriction, it's located on the very end of the system and gets pressure from the air velocity, it's supply branch is very short or a combination of the above.
If your supply branches are accessible, it's worth the money to have dampers installed on most if not all the branches and balance the system. The goal is that the airflow to each room is proportional to it's heat loss or gain so no matter how long or how often the system runs, all rooms stay roughly the same temperature.
It made a huge difference in my home and eliminated noise from the registers.
Adjusting airflow using the registers just makes a system noisy.
the AH is in the attic right on top of the mudroom (8x8) and is blowing a zephyr into the room.
Originally Posted by motoguy128
Yup...that pretty much sums up the problem. The supply may even be located on the supply plenum, which is generally considered a bad idea because it's noisy, and can be very hard to balance even with a supply damper.
Originally Posted by AvantGarde
Sounded like DIY instructions
I had a similar problem with by 2 back bedrooms that were located near the furnace in the basement. Their supplys were attached to the supply plenum 6" above the indoor coil. Even with the dampers mostly clsoed they were still noisy and had too much airflow while the front of the house was starved for air. The solution was to add a new 8"x10" branch to feed both supplies. This eliminated to noise but actually went a little too far the opposite way since hte total lenght of the ductwork was increased. I think now a 8"x12" would have been about perfect.
Last edited by beenthere; 03-10-2009 at 11:17 AM.
Reason: Removed DIY instruction paragraph