I was inspired by the other furnace heat deflector projects on this forum and made my own.  Given that I have a 177, the other furnace mods didn't fit.

Parts:

9 x 13 cake pan, Target, $1.99

misc. tin for cold air intake

heat resistant black paint

screws and pop rivets

Trim Lock metal edge trim (on order)

Tools:

tape measure

aviation tin snips

pop rivet tool

rubber mallet

vice

drill and bits

I think the photos say it all.

John, I liked your design a lot and thought I'd copy it but the 177 furnace is mounted 180 degrees to yours.  So, I had to come up with something else instead.

I received the edge trim yesterday and installed it on the cut edge of the cake pan and on part of the cool air intake. This addition makes it look more finished and hides my imperfections too!  I also used black silicone caulk on the cool air intake box seams.  The "wave" in the front lip goes away when the grill is tightened down with the mounting screws.

Exchanging ideas and solutions is one of the reasons this forum is so good!

Bob

Stephen, you’ve had to think about this when you saw it.  It should allow plenty of intake under the bed while the pan diverter blows the majority of the heat into the cabin from the first two stacks.  Can it be that simple?  

Ok, poke holes in it. 

As always, thanks for the ideas and recommendations.

Jeff

Jeff,

I think it's important to divert hot air output from the air intake of the furnace.  The top half of the right-most vents is hot air while the lower portion (where my tin box is mounted) is the air intake.

My furnace is mounted on the opposite side as yours under the bed and that's why I felt the need to make the air intake box.

I think your idea would work just fine.

Bob

Has anyone tried to simply put a small fan in that opening that will blow the heated air into the living space?

I'm sure it would reduce the airflow, the question is how much and what impact that has on heating capacity. Also, if the deflector worked to keep hot air from short cycling straight back into the furnace it could actually improve heat transfer to the room even if the airflow was less. 

Its hard to accurately measure airflow but if you cold quickly remove the deflecdtor you could measure the air temp coming off the furnace with and without it. If the temp went down without it you'd know that it was reducing airflow. 

Restrictions in the airflow would possibly mean more current flow thru the motor windings. But we can assume there is some 'leeway' in the specs.

What I don't know is: does the deflector increase the noise level or reduce the noise level?

As for airflow, as long as the opening of the diverter has the same or more square inches as the output size of the furnace output, then it should be okay. If it has less, it would restrict the flow.

I sized my cake pan to have plenty of volume to try and match the existing vents and airflow.  Same with the air intake.

My goal was to redirect the furnace air flow out into the living space instead of under the bed primarily because I have a rolling drawer under the bed and it was interfering with the furnace as well as getting too hot.

I also used a cake pan for our 179. I thought it worked grat until I started reading this post.

My question --I did not realize that some part of the front vent cover was an air return. So, I covered the whole front grill with the pan.  It seemed to work ok and certainly redirected the warm air into the cabin instead of under the bed-my storage area which doesn't need the heat. I don't think it is any louder.  However, I am sure the air flow has been reduced simply because the air is now being pushed against a dead end and must make a right angle turn to get outside of the deflector pan.   It seems logical this has to decrease overall flow and/or strain the fan.

what harm does covering the whole face grill do without having air return space????That return is not for combustion air so I am confused.

Is there another way to deflect the air so the cargo area is not overheated and still leave proper air return on a 179?? I don't want to use a fan, but some type of physical deflector.

Thanks as always for all of the great ideas.

Vann

Still, I would try to separate the return air intake from the heated air outlet.

I have a 179 too and was thinking about just placing a lightweight aluminum plate at an angle midway in the under bed storage area in order to divert air into the room while still leaving a large area for air to flow in and out to the heater. 

Cut the end off the cake pan so the air shoots straight out.

The air return is important.  All forced air furnaces require a cold air return whether in your RV or in your house.  That's why I went to the effort to make a separate "air duct" for mine.