We got new CARRIER Furnace 70,000.BTU, Model.# 58STX070E last year. Now we are remodeling our house and looking to move the ducts in the ceiling. Our contractor is saying that this furnace is not going to work as this is downflow venting and putting the ducts in the attic will require upflow-venting furnace.

Question is can this furnace CARRIER Furnace 70,000.BTU, Model.# 58STX070E be used for upflow venting.

I looked at the specifications for this furnace and it appears that this can be used for 13 different venting options, including upflow venting.

Here are the specs.
http://www.xpedio.carrier.com/idc/groups/public/documents/marketing/hw80-2002-50i~3.pdf

Can someone confirm that this furnace can be used for upflow venting?

Looks I got the answer here in the specifications. This furnace can be used for upflow, downflow as well as horizontal flow venting.

http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/58st-6pd.pdf

Yes but make sure you read the directions for each type of positioning. Many units need to have items moved or turned differently in the unit. It will be included in the install directions if any of that is necessary.