Year 2-Still Freezing

Some of you may recall my 42 page thread from last year where we covered all things Hot Blast.
Here it was if you want to remember.

Cold Air Return. Do I Need It?

I added a cold air return and moved the furnace to accommodate some "improvements"
I'm still freezing.

When the temps are 35+ outside I can stay comfortable but never can get it hot in the house.
My oversize furnace should force me to open windows and doors.
Yesterday, my cold blooded daughter had a blanket wrapped around her.
She's never cold.

Here's some data but I'm not sure how to address this and fix the problem.
I took readings with the infra-red shortly after firing the furnace this morning at 4 different registers about 20 minutes after clearing the ashes and stirring the coals real well.

#1 Almost directly over the furnace 115
#2 About 8' off the trunk line 104
#3 About 15' along the main trunk 75
#4 About 25' Along the trunk 64.

I'm losing 50 degrees.
Another idiosyncracy is the thermostat for the propane is 6'-8' from register #1 in the same room and the propane furnace kicked on at that reading of 115.

My over the door reading at the furnace, typically, is 325-350 but frequently much higher depending when, in the cycle, I measure.
Another weird thing is that the propane furnace, alone, will heat the house if I turn the thermostat up.
But that kind of defeats the purpose of the coal furnace.

How often do you clean the squirrel cage fan and the fan housing?

Have you checked the blower housing and squirrel cage fan
to see how dirty they are?

What type of furnace filters do you have?

Is it possible your furnace fan is too small for the load?

I have a Hot Blast 1557.
It's way bigger than I need but it was the only one they had on end of season clearance at Tractor Supply and I had a coupon.
It should cook me out of my house but doesn't.

I live in a relatively small single story; under 1000 sq.ft.

^^^^^ from 1st post of OP's linked older thread

IMO your stove is heating but just all that metal and tubing....I added into my HVAC system the area that holds my stove .. did not do anything positive which I attributed to the heat being "stolen" by the ductwork employed. I blamed the wifey of course.

Just my 2 cents....I don't think its related to your stove per se. Just physics.

You need to find a pic of an old gravity hot air and will all make sense. You are letting 90% of any heat out 4 sides bottom and parts of the top with no duct. All that should not be heat exchanger is load and ash pan door.

Thanks every one for the response.

How often do you clean the squirrel cage fan and the fan housing?

Have you checked the blower housing and squirrel cage fan
to see how dirty they are?

What type of furnace filters do you have?

Is it possible your furnace fan is too small for the load?

I don't have a squirrel cage and fan housing.

I have dual blowers that came with the furnace.
I am using pleated and change regularly.
Last time was 2 days ago.
I also oiled the blowers then

You need to find a pic of an old gravity hot air and will all make sense. You are letting 90% of any heat out 4 sides bottom and parts of the top with no duct. All that should not be heat exchanger is load and ash pan door.

I'm not sure I understand, ddahlgren
I don't know where you say all this heat is going.
I have a fire and ash door and the two provided openings for the hot air.
(And a flue)

Can I see pics of where the cold air return meets the furnace in the back and where it connects to the living space?

Sure, thanks, Lightning.

This one is coming out of the cold air return This one is going into the blowers

Here's what the new furnace looks like.

Thank you. Question...
Um, I see you used part of your existing duct work from the propane furnace. Whats to stop the air from just looping thru the propane furnace. There needs to be some sort of blockage to prevent this downstream of where you piped into the propane furnace's cold air return. I hope KY Speedracer will chime in. I believe he had to do something along these lines. I believe this could be a big issue if your warm air is just looping thru the propane furnace. What does the IR gun read on the propane's cold air duct down stream of where you piped into the propane's cold air return??

do you have a damper built into the plenum to stop your coal fired hot air from bypassing the house load and returning directly to be scorched again!

Sting wrote:do you have a damper built into the plenum to stop your coal fired hot air from bypassing the house load and returning directly to be scorched again!

This is exactly what I see happening too Sting..

ouch
not fast enough again

I was looking at you pictures of your set up I was wondering if your cold air return might be getting pinched off where it drops down from the celling I worked with that stuff and had a really hard time keeping it from kinking when I droped it down also I did not see any kind of damper in your stove pipe.

I do not have a damper.

If I did, I would have to completely shut off the propane furnace to use coal furnace.
At least, that's my reasoning.

I only have one other option for a return because of space limitations if I should need to separate it.
That would be to cut two openings in the floor above the furnace.
They are the same room

memco man.
Thank you.
I was careful to put a good sweep in it to avoid kinks