Another Goodman system!!: GCVC & SSX14

[chuckcrj]

interesting how you left out:

"ALWAYS CONNECT A MONOMETER TO THE OUTLET TAP AT THE GAS
VALVE BEFORE ADJUSTING THE PRESSURE REGULATOR. IN NO CASE
SHOULD THE FINAL MANIFOLD PRESSURE VARY MORE THAN PLUS OR
MINUS .3 INCHES WATER COLUMN FROM 3.5 INCHES WATER COLUMN
FOR NATURAL GAS OR 10 INCHES WATER COLUMN FOR PROPANE GAS."

which is immediately after it.

Sorry I left it out, it doesn't take away from the fact that they want their furnaces started up properly and verified.

If it means adjusting the manifold pressure or resizing the orifices, it needs to be done to correct an underfired furnace.

[chuckcrj]

If it's at 76% efficiency, and the heat isn't being absorbed, then how is the flue gas below the dew point, and condensating?

The heat was'nt absorbed because it wasn't being produced in the first place. The gas was being burned but it was burning at a cool temp.

When you have 6% O2 the flame temp is 2800°.
When burning at 12% O2 the flame temp is 2000°.

60% or more of the heat transfer in any combustion appliance comes from radiant heat off the flame itself. Which flame in is going to radiate more heat to the HX? The 2800° flame or the 2000° flame?

You can try it sometime, just restrict the air going to a burner to bring your O2 down. You will see your temp rise across the heat exchanger increase which means more btus are being produced. You didn't add any gas but you are getting more btus out of that same amount of gas!!

[seatonheating]

The heat was'nt absorbed because it wasn't being produced in the first place. The gas was being burned but it was burning at a cool temp.

When you have 6% O2 the flame temp is 2800°.
When burning at 12% O2 the flame temp is 2000°.

60% or more of the heat transfer in any combustion appliance comes from radiant heat off the flame itself. Which flame in is going to radiate more heat to the HX? The 2800° flame or the 2000° flame?

You can try it sometime, just restrict the air going to a burner to bring your O2 down. You will see your temp rise across the heat exchanger increase which means more btus are being produced. You didn't add any gas but you are getting more btus out of that same amount of gas!!

You are acting like this O2 in can be adjusted on a brand new furnace.

Ok, next install I'm going to install mesh over half of my intake pipe..


I get what you are saying, but it isn't practical. Time for you to bow out gracefully.

[davidr]

You are acting like this O2 in can be adjusted on a brand new furnace.

Ok, next install I'm going to install mesh over half of my intake pipe..


I get what you are saying, but it isn't practical. Time for you to bow out gracefully.

You might want to consider what he's saying instead of dismissing it.

O2 can be adjusted on a 90% 2 pipe furnace if you know what you're doing and you never have to touch the fuel to do it.

[chuckcrj]

You are acting like this O2 in can be adjusted on a brand new furnace.

Ok, next install I'm going to install mesh over half of my intake pipe..


I get what you are saying, but it isn't practical. Time for you to bow out gracefully.

I adjust the O2 on every startup and tuneup I do. New, old, natural draft, induced draft, condensing furnace, boiler, etc.... Very practical as it saves the ho money and makes their epuipment last longer.

I would never put a mesh screen in the intake. Their are other ways to adjust air.

As for bowing out I certainly can if its getting too uncomfortable for you.

[davidr]

If it's at 76% efficiency, and the heat isn't being absorbed, then how is the flue gas below the dew point, and condensating?

One thing to keep in mind is the different types of efficiencies that are out there and how they are defined.

It looks like Chuck was referring to a furnaces thermal efficiency which is the actual amount of BTUs being delivered from the furnace compared to what it is rated to output.

There are a lot of times that they don't add up.

[mike dixon]

the angle of your dangle, is in direct porportion to the heat of your meat, and the mass of your bottom remains at a constant temperature and pressure at all times given the relative humidity, grains of moisture per lb of dry air, and dry bulb, wet bulb is approiate. got it?

[seatonheating]

I adjust the O2 on every startup and tuneup I do. New, old, natural draft, induced draft, condensing furnace, boiler, etc.... Very practical as it saves the ho money and makes their epuipment last longer.

I would never put a mesh screen in the intake. Their are other ways to adjust air.

As for bowing out I certainly can if its getting too uncomfortable for you.

Sure ya do.

[ctcont]

Nice job there is alot goin on there i like the flex connecter here we have to hard pipe everything

[edbrown]

So how exactly do you adjust oxygen levels in a 95% furnace? Different restrictor plates in the inducer?

All of out techs use analyzers and adjust the air for atmoshpheric systems, but i have never heard of adjusting the air on a 95%. Have in extreme cases turned down manifold pressure for correct CO levels, etc.

This is a very interesting conversation......

[dunkman]

Wow, I guess I'm going to have to change the way I do things. I've been setting them up to 3.5" with the factory orifices for 8 years and now I find out it's wrong?

[seatonheating]

Wow, I guess I'm going to have to change the way I do things. I've been setting them up to 3.5" with the factory orifices for 8 years and now I find out it's wrong?

'cause he is a troll and his recommendations are funny. Let's just modify everything!!

Easy there, this can be a very interesting thread if you let it, instead of the above.
Tell you what. I'm going home and adjusting the gas pressures in my water heater because my kids take long showers..... Better combustion will equal more hot water, right?

[jeremy-lvhm]

The heat was'nt absorbed because it wasn't being produced in the first place. The gas was being burned but it was burning at a cool temp.

When you have 6% O2 the flame temp is 2800°.
When burning at 12% O2 the flame temp is 2000°.

60% or more of the heat transfer in any combustion appliance comes from radiant heat off the flame itself. Which flame in is going to radiate more heat to the HX? The 2800° flame or the 2000° flame?

You can try it sometime, just restrict the air going to a burner to bring your O2 down. You will see your temp rise across the heat exchanger increase which means more btus are being produced. You didn't add any gas but you are getting more btus out of that same amount of gas!!

I would be interested to see just how high your stack temperature shoots up when you do this as well. The proof would be in the combustion efficiency that pops up in your pretty little meter.

I agree with seaton. Something doesn't add up. And who the hell made that orifice chart? Doesn't look very official to me.

But this thread will live on I'm sure.