A/C, Heat Pump Is Not Heating Enough

[choaticwhisper]

I hope theres someone here that can kinda help me. My mothers house has split system a/c and heating.
I dont know how many btu or anything about it.

The system 3 returns 1 upstairs, 1 down stairs in the open area, and 1 vent on the system.
2 ducts coming out of the top; which spilt off to many different ducts. Some upstairs and some downstairs.
The thing is she has all the one downstairs closed off. She doesnt want to heat downstairs now. But the returns down stairs are still open. And this is how its been since shes had the system installed.

Now She is going to call the guy out tomorrw but I would like to know.
Are having the ducts downstairs closed messing up the heating?
Does she just need to close off the returns downstairs?
Open the ducts and cool downstairs?

Thanks for the help.

 

[UserName]

Most heat pump systems are designed to run at a certain load. Restricting return air, or shutting off discharge vents, unbalances the system. Shutting off one or two rooms is one thing, shutting off entire floors, is another.

I'm not an HVAC tech, I do mobile AC systems, but I have a very solid grasp of the principles involved. What I mentioned above, is what was told to me by the HVAC tech who service my ground-source heat pump last fall. I expressed my concern to him that the system might not be as efficient as it should be, and asked if I would help if I shut off rooms I was not using.

If there's an HVAC tech coming out anyway, I'd take his word with greater emphasis than anything you will get here, but I would be careful about restricting airflow while the system is running in heat mode. In theory, that could increase head pressures, which is hard on a compressor if it goes too far.

 

[DUQ]

I would try to put everything back to the way it was before she had problems. Sounds like the air flow is restricted and it's not picking up the heat from the coil.

Also; take a look at the filter.

 

[Morelite]

Where is the thermostat and what is the temp in that area? The system won't heat the cool areas if the area where the thermostat is is satisfied.

 

[choaticwhisper]

She has never had the downstairs vents open. But the Downstairs returns have been open. The A/C works well because downstairs stays cool even during summer. The heat she does like to use because its not warm. My guessing is because it cant heat the downstairs air that its taking in because its not putting any warmer air downtheir, and because its sucking air in and barly warming in putting it upstairs. Its only creating neg pressure, So taking even colder air from outside(any cracks.)

The thermostat is upstairs above the upstairs return. The temp upstairs on the themostat is 70F, but thats because she is also running LP heaters.


My thinking is that she just needs to heat downstairs also.

 

[Morelite]

The thermostat is upstairs above the upstairs return. The temp upstairs on the themostat is 70F, but thats because she is also running LP heaters.

That may be part of the problem, if the LP heaters are warming the air to the point where the thermostat thinks it is warm it will shut off the heating mode on the heat pump.

 

[MarNav1]

We had a new heat pump/furnace installed last year. Some adjustment of the vents may be necessary, we had to do that. Our house on heat pump does not "feel" as warm as it does on the furnace. The reason why is the air coming out with the HP is about 92deg or so. Your body is essentially 99deg so the air that comes out does not "feel" warm, in fact it doesn't "feel" like it is right. You would swear it isn't heating at all. When the furnace kicks on the air is about 20-25 degrees warmer coming out than the HP and it "feels" like it is heating. We thought the fan was running too slow on HP because it doesn't "feel" warm. Not so. If you run the fan too fast the air moving across the coil cannot pick up all the heat and it doesn't warm up enough. Then in the summer you can't get all the humidity out of the air. Our fan CFM was indeed too high by about 40% and slowing it down (it is adjustable) actually heated the house better (I know it sounds backwards). They measured the temperature rise between the incoming air and the outgoing air (HP and furnace) and it was right on spec (about 30 deg rise if I remember right). You can run the unit on "emergency" heat which bypasses the heat pump but then you lose the benefits of it. Our unit is a 2 ton Goodman unit. The unit is working how it is supposed to, the house is older and we are going to investigate putting more insulation in the walls to help with the heating. We also got an new programmable t-stat and it works fine. The 16x25x4 filter lasts about 6 months on our unit, no problems there. I hope you find a solution, it may be slippers and a bathrobe/snuggy.

 

[CobraMan]

I use to own a condo with a heat pump system and it never really got as warm as a conventional gas furnace system. However, I will tell you that there was a point where it felt like it was not putting out much warm air at all over a few month period and then it was only cold air coming out in the middle of winter.

Enter the service call - turns out the system was low on refrigerant! This could be part of the problem here so don't be surprised if they have to refill/recharge the system.

Good luck,
Tim

 

[MarNav1]

I agree completely with CobraMan, we have had ours checked and the refrigerant is fine. To the OP, have it checked of course, let us know if you get improvement and what was done. Looking back we would skip the heat pump and just went with a normal AC/furnace setup. It's not a teriible situation but it's like the temp is a couple degree's low when it is cold out and it's been an unusually cold year here. The t-stat says 74 and your body says 68, it's a strange deal IMO. The other thing they told us was keep the snow off the HP and away from the outside of it because that affects it too.

 

[will]

The thermostat is upstairs above the upstairs return. The temp upstairs on the themostat is 70F, but thats because she is also running LP heaters.

If you are running separate heaters, and the temp from the LP heaters is above the house thermostat - the thermostat will never kick in.

 

[choaticwhisper]

If you are running separate heaters, and the temp from the LP heaters is above the house thermostat - the thermostat will never kick in.

Yes, I know but She is running the LP heaters because the other one doesnt heat enough on its own. Which goes back to the problem I asked.
But She still hasnt called him out, I dont know why. I guess she doesnt want to hear she needs to heat downstairs also.

 

[vtunderground]

If that were my house, I'd open the ducts to the downstairs.

I have a full (finished) basement, that has it's own heating source. The rest of my house is noticeably more comfortable when I keep the basement warm than when I turn the basement heat off, even though the basement never gets below 60 degrees or so.

 

[will]

Yes, I know but She is running the LP heaters because the other one doesnt heat enough on its own. Which goes back to the problem I asked.
But She still hasnt called him out, I dont know why. I guess she doesnt want to hear she needs to heat downstairs also.

OK - so without the LP heaters, the heat pump does not put out enough heat - correct?

I don't know a lot about heat pumps, but I did learn something a few weeks back. I am in a Condo here in Florida. The pool uses 2 heat pumps to heat the pool . When the temp went below 40 degrees, the heat pumps did not work. Also - there was no heat in the condo units, they also use heat pumps. Turns out - if the temp goes below 40 degrees you have to have an separate heater to make the system work. It seldom goes below 40 and the condo did not want to spend the extra money for a separate heater.

 

[Badbeams3]

My guess is that you are on target with your thinking of blocking off the downstairs intake. It`s sucking in cold air. You should be safe closing it off as she has the air outputs close down there any way. That should cause the unit to circulate only the warmer upstairs air past the heating radiator/emergency heat coil ( heat strips kicks in after the temp outside drops below a certain point...around 35 degrees...heat pumps generally stop working below this temp)...and raise the tempature upstairs further on each passthrough. Good luck.

 

[Lasernerd]

My HP has separate heating elements for the heat when it is below 45 outside,,
it does like to draw in a little warm air which seems to increase the output of the HP