Radiant /ahu /ac

Bill_30

Did the heat cals's for a new home at 98,000 BTU. The home has infloor tubing in the basement for heat.Am looking to heat and cool the 1st floor/cool the basement with hydronic/DX air handler. The home needs 5 tons of cooling, about 2000 cfm. The Air handler I need to handle the 2000 cfm is rated at 150,000 btu. What size boiler would best suit this application and is the 150,000 BTU rating on the air handler a problem. Boiler will be used for infloor basement heating and 1st floor forced air. Thanks Bill

dconnors

HiVelocity

Try Hi Velocity havc system. Spacepak will give you 5 tons a/c and 100,000btu heat.

Ted_9

Just wondering Bill, did you do an accurate Heat gain calc? 5 ton seems big for a first floor and a basement.

Carl PE_2

The coil in the air handler is rated at maximum output. You can get anywhere from 0-150 by lowering the water temperature, reducing the flow, or a combination of both.

Carl

Bill_30

THANKS CARL, I APPRECIATE YOUR IMPUT. BILL

Bill_30

TED, I ACTUALLY THINK 5-TON MAY BE A LITTLE TIGHT. TOTAL SQUARE FOOTAGE IS ABOUT 4,500. THANKS BILL

Ted_9

Sorry Bill, I made the mistake and thought it was a 2000sq house. Think I read the post too fast.

Carl PE

oh yeah...

In related news, those heating coils are usually tested with 180deg entering water. Since you mentioned radiant, I'm guessing your hw temps are in the ~130 range. You should get a coil performance sheet from your ahu mfr at whatever water temp you're going to run the boiler, just to make sure that ahu is going to do the job. You might find out you need an extra row of coil to get your design btu at the lower water temp.

Bill_30

Thanks for the inforomation. This is an awesome wedsite. Bill