Hot Water Coil problem

subcooler

In the elbow

Wayco Wayne_2

I am close to

finishing a job that uses Solar hot water along with an air source heat pump. Because of a lack of ceiling space I couldnt put the hot water coil on top of the air handle, so I installed it vertically after the supply elbow on top of the air handler. I had the air handler blowing and the circulator running hot water through the coil. I had 2 temperature sensor dangling from a hole in the top of the duct on each side of the coil. I was measuring no air temperature rise across the coil, but was reading an 18 degree temperature difference oacross the water side. Hmmmmm. I then checked the temperature downstream from the coil at various heigths and the problem became clear. The air is coming out of an elbow and is hugging the top of the duct and only grabbing heat from the top 4 inches of the water coil. I need to force the air to spread out so it will get heat from the whole coil not just the top 4 inches. Any suggestions?? WW

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

dana_3

HOT H2O PROBLEM

YOU NEED TO PUT TURNING VEINS IN THE SUPPLY ELBOW

Brad White_161

Yes, Turning Vanes

Single-thickness if you can get them.

SMACNA has a detail using radius-proportional vanes through the entire elbow but you will need space downstream of the elbow before the coil. If you do not have that kind of space, then rolled single-thickness vanes will help a great deal.

If space is tight a perforated plate may also help after the elbow. It turns most velocity pressure into static pressure, leveling out the eddys.

Wayco Wayne_2

Thanks Guys

I have used flex steel and even 1/2 in hardware cloth to turn the velocity pressure into static pressure. Just wanted to pick brains and see if there was something else. If that doesnt help I may even install some turning vanes. WW

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"