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Forum Index => Heating & Air Conditioning Repair (HVAC) => Topic started by: def on February 13, 2013, 05:03:17 PM

Title: Heat pump performance in cold weather.
Post by: def on February 13, 2013, 05:03:17 PM
My heat pump doesn't provide much heat as the outdoor temperature approaches 30 F. Is there a better gas for a heat pump that will improve the performance of heat pumps in lower temperatures?

 :thanks:

 :popcorn:
Title: Re: Heat pump performance in cold weather.
Post by: domain on February 13, 2013, 05:06:10 PM
Like different refrigerant be put in to your heatpump for better performance? LOL no. Your compressor and overall unit are dedicated to the refrigerant designed for it. Proper charge would help. :D
Title: Re: Heat pump performance in cold weather.
Post by: def on February 13, 2013, 08:43:33 PM
OK, so a custom gas mix is out of the question.

I have a new 40# cylinder of R22 sitting in the garage. So, now all I need is some gauges to monitor pressure (vacuum) and fill the system to specification or to some level to optimize the cycle.

Is this something I should tackle myself? I understand the basics of refrigeration but have little experience other than filling the car with R134a from time to time.

Are there any how to videos anywhere that deal with this? Will I need to wait for hot weather to load the system correctly?

I understand that I could damage the system if I over fill or under fill it. Also, I plan to clean the evaporator coil and blow out the condensate drain line once I get into the air handler. Also, I am going to install a UV lamp in the air handler just before the evap coil to keep mold and mildew at bay.

So, give me your thoughts about these undertakings;

1- Go ahead. It sounds like your capable.

2- Your nuts. You have no idea what you're getting in to.

3- Call an ambulance before you begin work and have the EMTs standing by.

4- Stick to fixing your BMW motorcycle.

5- Call us once you recover from the explosions and electrical shocks.

6- Its easy. You'll do fine.

Please select one of the numbers for your response.

 :thanks:

 :popcorn:
Title: Re: Heat pump performance in cold weather.
Post by: lesguns on February 13, 2013, 09:49:34 PM
you need more auxillary heat.
Title: Re: Heat pump performance in cold weather.
Post by: Patricio on February 13, 2013, 10:56:04 PM
Auxillary heat is the ticket for a heat pump in a mild climate.
Title: Re: Heat pump performance in cold weather.
Post by: def on February 13, 2013, 11:39:03 PM
Yes, I have electric heat strips...

So, I guess I'm just going to have to live with it..........wait, unless I go ground source
Title: Re: Heat pump performance in cold weather.
Post by: jumptrout51 on February 14, 2013, 06:29:37 AM
What is the BTU of this H/P?
What size heat strips in KW?
Are they (heat strips) working?
What square footage is the house?
What brand and age of equipment?
The answer to your quest is above is 2 thru 5.
Title: Re: Heat pump performance in cold weather.
Post by: def on February 14, 2013, 09:16:26 AM
What is the BTU of this H/P? 3000BTU
What size heat strips in KW? Don't know but they do provide heat at low ambient temps (<15 deg. F)
Are they (heat strips) working? Yes.
What square footage is the house? 1550
What brand and age of equipment? Brand unknown but it was new with the house 5 years ago.
The answer to your quest is above is 2 thru 5. Hmm......not very encouraging.

 :-\  but  :thanks: anyway.
Title: Re: Heat pump performance in cold weather.
Post by: JWWebster on February 14, 2013, 09:50:53 AM
3000 btu would not even heat one room. You need 5000 btu per bedroom (basic rule of thumb)
Title: Re: Heat pump performance in cold weather.
Post by: def on February 14, 2013, 10:13:58 AM
3000 btu would not even heat one room. You need 5000 btu per bedroom (basic rule of thumb)

Mr. Webster, I made an error  :oops: (a rare ocurance). My H/P is 3 tons. You're correct, 3000 BTUs is....well, I can rub my hands together and get 3000BTUs.  ::)

Sorry
Title: Re: Heat pump performance in cold weather.
Post by: jumptrout51 on February 14, 2013, 02:55:37 PM
To check your refrigerant charge on a R22 hp you would use the sucking port using your blue gauge.
Not the suction port on the primary service valve.
With the unit set for heat and running,the suction pressure would be equivalent to the outside ambient temperature plus or minus 3 degrees. EXAMPLE; 40 degree pressure outside temp would be 37-43 degrees.
That would be a good charge.
If variable is lower,add refrigerant.
Is this a orifice delivery system or a thermostat expansion valve?
Title: Re: Heat pump performance in cold weather.
Post by: jimbo6679 on February 14, 2013, 08:35:25 PM
Most older heat pumps would cease operating when ambient was down to 30.    New units have a wider operating range.

First, do you have your EPA card to touch R22?   They take a VERY dim view if you do not.  Do you have a recovery machine?      Don't take offense if you are up to speed....  I just throw this out for everyones info.
Now,  this is not shade tree mechanics, where you just shove a little R134 into your car and come back next summer.    "fiddling" with a heat pump will get you into uncharted trouble.   You need to have proper equipment, and based on the data plate and install manual for your unit, determine what the proper subcooling should be based on house temp and outdoor ambient.    Adjust charge IF NECESSARY.
Title: Re: Heat pump performance in cold weather.
Post by: lesguns on February 14, 2013, 11:05:21 PM
ground source is the best for heat pumps but real expensive. try 1500w infared heaters for xtra aux. just a thought.
Title: Re: Heat pump performance in cold weather.
Post by: def on February 15, 2013, 09:08:42 AM
Most older heat pumps would cease operating when ambient was down to 30.    New units have a wider operating range.

First, do you have your EPA card to touch R22?  No EPA thing but, I do have a valid passport They take a VERY dim view if you do not.  Do you have a recovery machine? No, but I do have one of those stair stepper machines that I exercise on every morning,      Don't take offense if you are up to speed....  I just throw this out for everyones info.
Now,  this is not shade tree mechanics, where you just shove a little R134 into your car and come back next summer. I usually just let system pressure suck the refrigerant into the low pressure port...I don't have to shove it.     "fiddling" with a heat pump will get you into uncharted trouble. You need to have proper equipment, and based on the data plate and install manual for your unit, determine what the proper subcooling should be based on house temp and outdoor ambient.    Adjust charge IF NECESSARY.

You mention fiddling...I don't play violin but do play accordion...does that help?  :tiphat:

Of course, I'm being facetious (silly) here.  :rofl:  After a bit of consideration, I think I'll leave the heat pump alone.

But, I will clean the coil and install the UV lamp. I need to find switched 120VAC in the air handler and tap into that for the UV power when the blower is running. Any thoughts?  :thankyou:

 :popcorn:
Title: Re: Heat pump performance in cold weather.
Post by: def on February 15, 2013, 09:21:44 AM
ground source is the best for heat pumps but real expensive. try 1500w infared heaters for xtra aux. just a thought.

I have been contemplating a ground source system should I ever build another house. I am now thinking about another house and a heated swimming pool, as well. Ground source would be good for heating the pool, as well.  ::)

Now, I have to find a way to balance the load between the pool, two houses, domestic hot water demands and the phases of the moon.  8)

I don't know if I can balance a variable load with the equipment that is currently available. I may have to design something myself and fabricate some purpose built valves to distribute coolant...more work to be done. I have plenty of real estate for the ground source heat exchange plumbing but have determined that moon phases need not be considered.   :)

And yes, your suggestion of some auxiliary infrared heaters is appropriate and appreciated.   :thanks:

Title: Re: Heat pump performance in cold weather.
Post by: JWWebster on February 15, 2013, 11:58:00 AM
I know a guy who added another wall 1 foot from his existing wall on the south facing side of the house. He installed a thermostatically controlled solar driven fan to pump the hot air inside the false wall to inside the house. Cut his power bill down to nothing in winter.
Title: Re: Heat pump performance in cold weather.
Post by: def on February 15, 2013, 12:09:48 PM
I know a guy who added another wall 1 foot from his existing wall on the south facing side of the house. He installed a thermostatically controlled solar driven fan to pump the hot air inside the false wall to inside the house. Cut his power bill down to nothing in winter.

Mr. Webster, This sounds like an excellent idea. Does this fellow have any details? Materials, dimensions, etc.? Where is he located geographically? More details please...

 :thanks:

 :popcorn:
Title: Re: Heat pump performance in cold weather.
Post by: JWWebster on February 15, 2013, 04:59:14 PM
He lives on Fowl river near Belengrath gardens. We have mild winters here. I think the house was featured in a newspaper article but I cannot find it. You ever hear of a beer can heater?
Title: Re: Heat pump performance in cold weather.
Post by: def on February 15, 2013, 05:20:03 PM
He lives on Fowl river near Belengrath gardens. We have mild winters here. I think the house was featured in a newspaper article but I cannot find it. You ever hear of a beer can heater?

Are we talking about Fowl River near Bayou La Batre? Heck, I'll just ride the BMW down there and visits with him. Does he carry a gun? Is he...ya know....right? Is there any danger?
Title: Re: Heat pump performance in cold weather.
Post by: def on February 03, 2014, 10:57:06 PM
If anyone is interested,  I have a new 40 lb tank of R22. Let me knkw if you would like to trade for it.

Otherwise! I'll just put in the trash.
Title: Re: Heat pump performance in cold weather.
Post by: appltech on February 04, 2014, 10:35:59 AM
^^^youre kidding right???


Sent from my iPhone using Tapatalk
Title: Re: Heat pump performance in cold weather.
Post by: def on February 06, 2014, 07:54:35 AM
I don'need it so, out it goes. Do you want it?
Title: Re: Heat pump performance in cold weather.
Post by: niobrara on February 06, 2014, 08:03:54 AM
Yes and I will pay to have it sent to me.
Title: Re: Heat pump performance in cold weather.
Post by: def on February 08, 2014, 12:54:59 AM
I live north of Birmingham, AL. What's it worth?
Title: Re: Heat pump performance in cold weather.
Post by: dennispalmer on July 12, 2018, 05:52:40 AM
Below are few steps that can be useful to improve the performance and efficiency of heat pump.
Change air filter :
Fix duct leak.
Service your pump on regular interval.
Use programmable thermostat.
Title: Re: Heat pump performance in cold weather.
Post by: Jonhb87 on July 12, 2018, 10:47:54 AM
Below are few steps that can be useful to improve the performance and efficiency of heat pump.
Change air filter :
Fix duct leak.
Service your pump on regular interval.
Use programmable thermostat.

You should also have a professional technician service your heat pump at least every year. The technician can do the following:

-Verify correct refrigerant charge by measurement
-Check for refrigerant leaks
-Inspect electric terminals, and, if necessary, clean and tighten connections, and apply nonconductive coating
-Lubricate motors, and inspect belts for tightness and wear
-Verify correct electric control, making sure that heating is locked out when the thermostat calls for cooling and vice versa
Verify correct thermostat operation.
Title: Re: Heat pump performance in cold weather.
Post by: def on July 12, 2018, 01:14:46 PM
Interestingly enough. I recently experienced a failed condenser fan motor (partial bearing seizure) in the condenser unit. These motors typically use sleeve bearing (no means for lubrication) and are made in Mexico. These motors cannot be repaired successfully due to their pressed and crimped construction. I ordered and installed a new condenser fan motor (about $100.00 on Ebay) and all is now well....except for one thing... when the condenser shuts off, there is a noticeable "bang" noise. I do not know the source of this  bang...I have checked mounting screws and other stuff I disturbed when I removed the fan assembly and can find nothing wrong or adrift. I may replace the load contactor in the condenser just to eliminate it as the culprit. I may also change the motor start capacitor for the same reason.

Any thoughts from any of you experts or non-experts regarding the bang noise?

Also, does anybody wish to purchase my unwanted R22? If so, let me know. The R22 weighs about 36 lbs. which means that the cylinder is likely about 3-4 lbs. shy of a full cylinder.
Title: Re: Heat pump performance in cold weather.
Post by: Jonhb87 on July 17, 2018, 12:04:07 PM
Interestingly enough. I recently experienced a failed condenser fan motor (partial bearing seizure) in the condenser unit. These motors typically use sleeve bearing (no means for lubrication) and are made in Mexico. These motors cannot be repaired successfully due to their pressed and crimped construction. I ordered and installed a new condenser fan motor (about $100.00 on Ebay) and all is now well....except for one thing... when the condenser shuts off, there is a noticeable "bang" noise. I do not know the source of this  bang...I have checked mounting screws and other stuff I disturbed when I removed the fan assembly and can find nothing wrong or adrift. I may replace the load contactor in the condenser just to eliminate it as the culprit. I may also change the motor start capacitor for the same reason.

Any thoughts from any of you experts or non-experts regarding the bang noise?

Also, does anybody wish to purchase my unwanted R22? If so, let me know. The R22 weighs about 36 lbs. which means that the cylinder is likely about 3-4 lbs. shy of a full cylinder.

Rattling, Thumping or Banging Noise

If you hear a loud clanking noise coming from your unit, these sounds typically indicate that something has gone awry with your blower assembly or motor. Motor mounts can sometimes come loose, or your blower may be out of alignment. If the sounds become louder when your blower is running, turn your system off immediately. This means something has broken or disconnected entirely. Call a trained tech for inspection and repair.
Title: Re: Heat pump performance in cold weather.
Post by: def on July 17, 2018, 12:49:01 PM
The bang occurs at condenser shutdown otherwise, the HVAC system is performing normally in our 90F summer heat. I suspect it comes from the condenser fan motor. When I installed the new motor, I was careful to insure the fan was clearing the cowling. I installed new zip ties to keep the wiring from contacting the fan. I believe the motor design is poor allowing the motor armature to rise and fall as the motor is energized and deenergized...speculation on my part.

As for contacting an expert, installing an electric motor on the condenser grill and attaching the wires to the existing lugs on the motor start capacitor is straightforward...anyone with average skills and tools could do the job.

Now, I am going to disassemble my flat screen TV (I have already replaced the DLP chip) and clean the light engine and cooling fans. That too is a straightforward job most anyone can do.
Title: Re: Heat pump performance in cold weather.
Post by: def on July 17, 2018, 01:08:13 PM
Below are few steps that can be useful to improve the performance and efficiency of heat pump.
Change air filter :
Fix duct leak.
Service your pump on regular interval.
Use programmable thermostat.

You should also have a professional technician service your heat pump at least every year. The technician can do the following:

-Verify correct refrigerant charge by measurement
-Check for refrigerant leaks
-Inspect electric terminals, and, if necessary, clean and tighten connections, and apply nonconductive coating
-Lubricate motors, and inspect belts for tightness and wear
-Verify correct electric control, making sure that heating is locked out when the thermostat calls for cooling and vice versa
Verify correct thermostat operation.

When I was inside the condenser unit to change the fan motor, I cleaned the bottom of the case to remove the few leaves that had fallen into the condenser. I also removed electrical connections and sprayed with aerosol silicone and checked for secure electrical connection. Next, I looked for any evidence of a refrigerant leaks often seen by refrigeration oil at a leak source. All connections were dry and clean. My filter is an aftermarket filter that gets washed routinely. I also have a prefilter that sits in front of the main filter which goes into the washing machine from time to time. My air handler has no belts or lubrication points. The evaporator fan makes no noise and operates normally. Actually, I think the system is operating normally and I get good condensate flow out of the condensate pipe. I do wish I could get at the evaporator coil to clean it thoroughly...that may take the services of an HVAC person.
Title: Re: Heat pump performance in cold weather.
Post by: victoriabam on January 01, 2019, 09:53:15 AM
That guide is too helpful. Thanks everyone for suggestions.
Title: Re: Heat pump performance in cold weather.
Post by: def on January 01, 2019, 03:32:04 PM
The bang comes at condenser fan shutoff. It is back EMF in the motor winding...nothing to fix.