Attic air handler blowing cool air

suchinator

Just bought a house and system consists on two triangle tube prestige series boilers with an indirect water "heater"/ storage tank. I have two carrier air handlers in the attic for the two upstairs zones. The units use hydronic coils and a blower to heat and distribute the air. The boilers are set to beat the water to 180 degrees and the circulator pumps are working fine. The supply and return pipes are both very hot to touch. The air handler is turning on and air is blowing out the registers but it doesn't feel very hot and sometimes even cold. If hot water is getting to the air handler and blower is working, why is cold air coming out the vents? What should the temp be of the air coming out of the registers? The first floor air handlers are in the basement and the air coming out the registers are much warmer on the first floor. The attic is unconditioned and same temp as outside, should I insulate the air ducts in the attic (best way to do this?) can you insulate the air handler as well? Any help is appreciated. Thanks.

njtommy

Try and get an accurate temp reading of the supply air temp coming out of the vents. Also the fan speed on the air handlers my be set too high.

Jamie Hall

If both the supply and return pipes are hot to the touch, that tells you that the air handler isn't extracting enough heat, which is usually an air flow problem. However, hot to the touch at 180 or thereabouts is a little hard to judge. If you have access to an IR thermometer, the thing to do is wrap electrical tape around both the inlet and the outlet -- one wrap is fine -- and shoot that with the IR thermometer (the tape gives you a standards surface for the thermometer to read). A typical delta T would be around 20 degrees, more or less.

If the delta T is much less, it really suggests that the air flow is reduced for some reason.

As to the insulation... yes indeed! That could be a good chunk of the problem, too! Make sure that all of the joints in the ducting -- both on the inlet and the outlet sides -- are really truly well sealed, as well as all the connections to any registers or what have you. Then the ducts themselves should be insulated. There are ways and ways to do that -- but the redneck approach is to use a roll -- or rolls -- of 4 inch to 6 inch fibreglass and wrap them.

4Johnpipe

Have you checked the air filters? If they are clogged and the duct system is leaky it will pull air through the leaky duct as apposed to the return ducts...

unclejohn

Sounds like air. I would however also check and make sure the outdoor A/C unit is not running as well.