Temp rise

[hipster dufus]

Pondering heat pump issues. What should my temp rise b, ballpark, between my return and my outlet vents. I know there are a lot of variables. Just tryin to figure out if I need a service call.tia

 

[Batjack]

Pondering heat pump issues. What should my temp rise b, ballpark, between my return and my outlet vents. I know there are a lot of variables. Just tryin to figure out if I need a service call.tia

Ain't never pondered that, I just know that if it's run'n it's legs off to keep up or cut'n on/off .. on/off.. on/off it's time to "Call the man Aunt Bee."

 

[Oldstick]

No expert or HVAC specialist here, but very small temp rise with a lot of extra run time to provide heat to the house on a heat pump in colder temps like we are experiencing lately. If temps drop even lower, like below freezing, the auxiliary heat will be coming on more and more to compensate for the outside temp differential.

Best thing to do in winter with a heat pump is choose a temp that is tolerable inside for you and family. Either 65, 68, 70+ or whatever and leave it there. The less it has to go up and down using auxiliary heat the better for your electric bills.

 

[Oldstick]

One simple test you can do yourself is go to the inside furnace unit and feel the freon lines running into it when the heat pump is running. The main line should be hot to the touch. Not blistering hot but probably hot enough to be uncomfortable. This would be an indication that it might be working normally. The opposite of working in cooling mode during the summer. The outside unit will be ice cold and freezing, thus the necessity of the defrost cycle during winter.

If the freon line is hot but doesn't have pipe insulation, go to lowes and get some, I might add. Applies to both inside and outside freon lines.

 

[specialk]

piggy backing this thread, when it hits 32 degrees mine starts to freeze/frost over, but it still keeps the house at the thermostat temp....also my emergency heat has to be switched on manually i believe..

 

[Batjack]

piggy backing this thread, when it hits 32 degrees mine starts to freeze/frost over, but it still keeps the house at the thermostat temp....also my emergency heat has to be switched on manually i believe..

Emergency heat is only for when the outside unit or the lines freeze up and quit working. Your inside unit as electric heat strips in it to use until you get the problem fixed.

 

[Oldstick]

Emergency heat uses the electric heat strips only, like ya'll said for when the compressor unit outside is not working. However most all heat pumps I have seen will also automatically kick on the heat strips whenever the outside temps drop below a point where the normal reverse compressor system is not able to keep up. For example, whenever the inside house temp (as read by the house thermostat) is already several degrees below what the thermostat is set for.

 

[Milkman]

Pondering heat pump issues. What should my temp rise b, ballpark, between my return and my outlet vents. I know there are a lot of variables. Just tryin to figure out if I need a service call.tia

Not a direct answer to your question but the temp shouldn’t be more than 2 degrees difference between actual room temp and your set point on the thermostat.
The emergency heat should come on if it drops lower.

If your emergency heat strips are coming on during this non freezing weather you may need that service call

 

[Oldstick]

Yep, 2+ degrees drop is what I've always understood before the heat strips come on in normal operation. But, as Mr. Milkman said, this usually doesn't happen until outside temps go very low.

OR if you are turning your unit low or off while gone, then coming home and turning it on to warm back up more than 2 degrees.

 

[hipster dufus]

U guys over thinkin, what's the temp coming out ur registers when unit is running?

 

[georgiadawgs44]

Did a startup on a new 4 ton heat pump system with 10 KW heat kit. last night. Outdoor temperature was low 40’s, indoor temperature was 55. Supply temperature was between 85/90 at start up. After an hour the temperature in the house had risen to 65 degrees. Supply temperature was 118 at that point. I wasn’t really measuring it across the coil, rather just checking different supplies in different areas of the house. The auxiliary heat was running the whole time as the temperature differential was so much because the new house was so cold when we started the system up for the first time.

 

[hipster dufus]

So, what should b temp without aux heat at registers?

 

[georgiadawgs44]

To be honest I don’t know the answer to that question. I’ve never checked one like that. I can tell you a few things to check.
Make sure the outside unit is running.
Make sure the condenser fan is running.
The air coming from the top of the outdoor unit should be very cold.
The suction line going into the outdoor unit should be hot. Hot enough that you can’t leave your fingers on it. That’s the larger copper line coming from the air handler that should have insulation on it.
Make sure the filter is clean.
Check for ice forming on the outside coil. Ice is normal but the unit should be going through a defrost cycle periodically to melt the ice. Excessive ice could be a low on refrigerant problem.

 

[ilbcnu]

On the cooling side the delta t should be 18 to 22 degree difference. Heat side 30 plus

 

[Oldstick]

Don't know the exact temp but I have hand tested mine many times and it's not exactly what I'd call really warm without the aux heat running. I'm estimating maybe 80 something? Takes a half hour or more to raise the house temp 1 degree.

Then with the aux heat on it's enough to feel the warmth. Maybe 100 or more

 

[ilbcnu]

Take the temp of the incoming air at the return and the temp coming out of the nearest register to air handler and subtract. Example- 90 at register minus 68 at return = 22 delta t

 

[Oldstick]

You got my curiosity up Hipster. Bored and nothing better to do I hung a digital cooking probe into a register that is furthest away from the furnace. Outside 45 in the shade and house temp sitting at 70. So I bumped the thermostat up to 71. Register temp peaked at 81. I then bumped up to 74 so as to kick on the aux heat. Register Temp peaked at 111 then.

My unit is an older one still running on Freon 22 and vents and everything else is in the attic.