A request was made to post up some pix of my warm-air intake. It isn't fancy, but it does the job...
First, I removed the cold air tube and resonator (year-round: weight reduction) and the exhaust manifold heat shield.
Pick up some flexible exhaust tubing at the auto parts store -- you can bend it to conform to your needs. I drilled a hole in the side of my airbox to allow the tube attachment. A zip-tie holds it in place.
The difference in many airboxes vs. the Integra setup is the tubular style of the filter and a clean seal at the air intake directly from the filter assembly. This allows "dirty" air to enter at any place in the box. The stock air entry (front-bottom of the box) was covered with duct tape -- this makes it easy to peel it away when summer comes around again.
The hole was drilled to allow a tight fit. Simply crimping the end ensures that it won't slide out -- the tight fit allows it to not slide into the filter causing damage.
The piping doubles as the summer, cold-air intake, so the it's' a bit rusty, but it works. In my experience (with some Honda engines), if you get the IATs into the 100-110F range, you'll notice an increase in FE + faster warmups.
If your airbox is a "clean" setup, such as a drop-in, find the intake source and setup a similar routing . It may take some additional plumbing and duct tape
Enjoy!
-Rick