I assume you are in an all electric situation and are replacing a 1.5 ton HP system. I am unequivocally opposed to purchasing HVAC through a big box store including HD. With that said, I prefer the Rheem system over the Lennox. This is the matching equipment AHRI number you should be looking for.

8224074 ActiveSystems RHEEM; RUUD RHEEM SALES COMPANY, INC. RP1518BJ1 RH1T2417STAN 650 18500 13.00 16.00 15700 9.00 91001HRCU-A-CB Yes 147355 Yes

verify AHRI number with quoting dealer.

I can not decipher the other information you provided.i would also get a quote on a Trane XR 15/16 and identical equivalent from sister company Am Standard. I would want HW Mdl thermostat #8321.

IMO

Good afternoon:

Thank you for commenting on my questions. Somehow the format messed up and it was hard to read. I am wondering if you can tell me if the following systems are comparable:

1. RP1518BJ1 RHEEM 1.5 TON 15 SEER HEAT PUMP

2. RH1V2417 2 TON RHEEM SINGLE STAGE AIR HANDLER - ECM 707933 1 XBH-17A07J

3. 7KW RHEEM HEAT STRIP

and

1. Lennox model 14HPX018 heat pump outdoor unit

2. Lennox model CBX25UHV-024 indoor air handling unit with variable speed blower

3. 7.5 kw auxiliary electric heat

Thanks.

Sonya

The Lennox is a low end POJ...

Thank you. When I look at the EER/HSPF numbers, the Rheem has 15 EEER/13 EER/9 HSPF while the Lenox has 15.5 SEER/12.5 EER/8.5 HSPF. I am a novice so I thought that they are comparible, right? In PA here, in my opinion, heating is more important than cooling. So is it much difference between 7 or 7.5 kw auxiliary heat? Thanks :-)

No they are not comparable...look behind the numbers and features...the Rheem has much better HSPF heating efficiency, also electronic demand defrost which saves you on wear and tear, unnecessary and expensive defrost calls...plus Rheem is simply better HP....Lennox made south of the border too...still like Trane and AmStd selections I gave you better...I am done here...good luck...

IMO

Still trying to decipher your first post. There is something about duct board. Any duct modifications should be done with sheet metal.

The auxiliary heat strips are a add on to the heat pump. The sizing should be based on the load calculation for your house, and the size of your heat pump. A difference of 0.5 kw is will likely not make a difference.

I think I have it deciphered...

===================================================

Home Depot Quote:
1 RP1518BJ1 RHEEM 1.5 TON 15 SEER HEAT PUMP R410A 707915
1 RH1V2417 2 TON RHEEM SINGLE STAGE AIR HANDLER - ECM 707933
1 XBH-17A07J 7KW RHEEM HEAT STRIP FOR AIR HANDLERS
707978 HONEYWELL 6220D THERMOSTAT 327002 1 AIR HANDLER

This kit contains all accessories to install air handlers
4300-11 RX11 2LB RE-FILL CAN
4/CASE NU-CALGON 5-7 TON SYSTEMS
1 MISC MATERIALS MISC MATERIAL FOR INSTALL
1 2 IN HALF SHEET HALF SHEET OF 2 IN DUCTBOARD 703688
1 19 5X12 TRANE AIRHANDLER PLENUM 350093
1 18 x 10 2 IN 4 FT LENGTH OF DUCT 703688

Another quote: Install Lennox model 14HPX018 heat pump outdoor unit Install Lennox model CBX25UHV-024 indoor air handling unit with variable speed blower Install 7.5 kw auxiliary electric heat Install new insulated refrigerant piping ... Thank you so much for your help. Sonya

===================================================

BTW, I'm about an hour south of Philly, in MD... I recently installed a 3.5T Rheem heat pump and love it!! It's sized for AC, but I have no problems with it maintaining the indoor temp at 70F, even when the outside temp is 30F. When outside temps get below 30F, I have a propane furnace that takes over... I'm thinking about reducing the temp for switch over, but I'm not sure if it would be more efficient to do because when outside temps get below 35, the heat pump runs for long periods of time ... like 30+ mins ...

Good luck!!

Thank you for your comments.

I am debating between these two quotes. One has the Lenox system (15.5 SEER/12.5 EER/8.5 HSPF), or Rheem system (16 SEER/13 EER/9 HSPF). The Lenox was proposed by a local contractor which quotes a lower price. The Rheem system was proposed by Home Depot related contractor which has a slightly higher price (not much though, only $350 difference).

I wonder if the 0.5 difference in ratings make a difference. A friend says that it will make a difference - for example $10 or $20 per month electric bill difference.

Does anyone know? Thanks.

sonya

I don't think it will make any difference... The parts themselves don't 100% determine their efficiency... A lot has to do with how it's setup. Yes, the Rheem setup tested for better efficiency, but if the installer goofs and slightly over or under charges the system, you're not going to get what is listed... You, as a consumer will never know as long as you feel it heat/cool your home...

Don't buy your HVAC equipment through Home Depot. You will be paying a higher price and most likely not get a good installation. Get more quotes, there are many HVAC dealers in the Philadelphia area.

The difference in efficiency ratings are small. It is more like $1 or $2 per month, not what your friend told you.

Absolutely disagree....significant difference on the heating side...people on this forum make comments not backed up by facts much less HVAC knowledge especially about brands/models....learn to read the AHRI site and what the numbers mean along with estimated operating costs...

I took your advice and looked up the AHRI numbers.

Lennox: AHRI no. 7524647 Heating cost: $431

Rheem: AHRI no. 8224075 Heating cost: $355

So the difference according to AHRI is $76 per year. For the Philadelphia area the heating season is 4-5 months, so the monthly savings is $15-$19 per month.

So a HSPF difference of 5.5% yields a cost savings of 21%. I suppose this happens because the HSPF is not a linear function over the operating temperature. I am always thinking in terms of AC and furnace efficiency.

Remind me to stay out of these heat pump discussions. I usually get myself into trouble.

Thank you so much for all the helpful discussions :-) They educated me and helped me a lot. As a customer, do you know what we can do to help the contractor who install the HVAC system? I guess one question is to make sure that the system is charged correct (not over or under charge)?. Anything else that customers can do to help make sure that system is installed correctly?

Here's a link to a savings calculator...

http://www.energystar.gov/sites/default/uploads/buildings/old/files/ASHP_Sav_Calc.xls

I still say go with the better installer..

Hi, thank you for your comments. "How good is an installer?" is something that I do not know how to check. The only things that I could think about are: how many years of experience, how good the company's review. Anything else we could do to judge? Thanks.

Ask your friends and neighbors to see who they might recommend and why. There's also a HVAC TALK forum where a bunch of people in the industry hang out at. You should be able to get references from there too.

If you can't find anyone you trust, make sure you get educated a bit. Shoot, get educated a bit anyway.

For example here are some things you want to look for.

Flushing the line set with Rx11 or similar ... a good
thing, since the odds are your old system used mineral oil, which isn't
compatible with R410a.

They're going to have to braze the refrigerant lines... make sure they flow nitrogen while brazing.. This video shows the difference when nitrogen is used and not used. https://www.youtube.com/watch?v=Bpqxbc9XQ5Y You want nitrogen used because if not, the oxidation can clog things up.

Are they using a micron gauge down to a minimum of 500 microns of vacuum,
then have it hold there to make sure the lines are tight and there's no
moister in the system?

Another thing you want to see from them is how they charge your unit. You want to make sure they check the Superheat and Subcool. When it's to cold out, they'll probably weigh the refrigerant in vs sh/sc. Sure your new heat pump will work with a weigh in, but in the spring when the weather warms, you want them to come back to double check the charge because weighing it in only gets you in the ball park.

There's lots of stuff a good installer will do that others might not or hack. It's best to get educated a bit so you can ask questions of your possible installer...

If you ask a installer about brazing, and they say they don't use nitrogen because they've been doing without it for decades, will you be happy? I don't think you will be because I don't think you want your new heat pump not running at 100% or breaking down, 6 months, a year, or down the road. Bad installs don't always show right way.... On the flip side, sometimes even hacks get lucky ... My buddy's now 3 yo system was installed without a micron gauge, no nitrogen flow, and no line set flush, but it's till chugging along... He also told me it was charged with the "beer can cold" method but he doesn't care since it's still working.

Refrigerant lineset must be sized to brand/mdl recommendation whether new or flushed...this is a big deal if you expect to get the performance/efficiency that new system is capable of...still don't care for purchasing new HVAC through big box stores...

Happy New Year!

Thank you all so much for your help. I selected Home Depot and installed a new Rheem heat pump.

I was actually pretty disappointed - the night that the HVAC was installed (outside temp in the mid 30s), the pump ran all night without stop. The next day (outside temp in the mid 40s), a technician came and checked the system - he said that he could not find anything wrong - he said that the thermoset was not accurate - it is 4 F off so the thermoset says that it never reached the temperature while it already did (we did not think that the thermoset was the problem because the temperature inside the house did not continue shooting up). A senior technician came last week (the outside temperature was in the mid 50s). He really only did minor adjustment (added 8 oz of refrigerant and lowered the air handler's fan speed). He said that the forced air is about 24 F higher than inside temperature (we set the inside temperature to be 70C). When the auxilliary heating was on, there was an extra 10F increase in the forced air. The pump sometimes stopped during that day so we thought maybe it was fine. Last night the outside temperature was in the 30s, the heat pump ran all night and no stop again.

Could someone please tell me if it is normal for the heat pump to run all the time when the outside temperature is in the mid 30s? We have two other zones in the house which have also heat pumps with auxilliary electric strips, they both ran several minutes, then stop several minutes (never ran continously), even at this low temp of mid 30s. I suspect that the air temp from the new heat pump is not strong enough and the heat pump continues to run to keep up with the temperature. What do you think?

Also, what could I do at this situation? Thank you so much for your help

Sonya

Last night you had the thermostat set to 70, the outside temperature was in the 30s, and the heat pump ran all night? Was the auxiliary heat on all the time?

Which thermostat did you get and how was the 4 degree problem resolved?

The temperature is forecasted to be 18 degrees on Monday night, so if the heat pump with auxiliary heat can't keep up now, it is only going to get worse.

What you describe is not normal in my opinion. This sounds like an installation problem, but let's see what the heat pump experts have to say about this.

If sized correctly, no it is not normal. For a brand new system, I don't consider adding 8 oz of refrigerant a minor adjustment. Rheem has charts for charging the new HP correctly. Another tech should come out with his charts and check the charge against manufacturer recommendations taking into consideration outside temp. That would be the starting point at least to eliminate the cause of the problem as a poor charge. While not necessarily a good diagnosis tool, I would take several supply readings at different locations several times a day noting time of day, supply temp, and outside temp. I like facts. What is thermostat setting? Is HP maintaining setting? You can get a cheap digital thermometer at a big box store. New refrigerant lineset installed or old flushed? If old flushed, is it to manufacturer spec? What size heat strip installed?

IMO

Are you sure it ran non-stop or did it just feel like it ran all night?

I'm just south of you in Cecil Co, MD and we were in the low 30's last night. I was up till 4am, so the odds are, I was up when it was coldest of the night. I don't have electric heat strips and I know my furnace never kicked in. My setup is set to lock out the heat pump then switch over to the gas furnace when outside temps get below 30. When the furnace runs, the air is really toasty, not lukewarm like the heat pump.

My heat pump cycled normally last night.. around 1.5 hours of run time and it would sit for what felt like forever before it restarted.

Is your home not insulated well? For it to run non-stop, in the 30's, installation is an problem and or it's under sized.

Do you know how long your line set might be? Unless your line set is around 30ft long and no additional Puron as added at the time of install, you might be over charged now. Rheem should have shipped your HP with enough Puron for 15ft of line set. You should have only needed more Puron if it were longer.'

BTW, on my 3.5T Rheem with a 7/8" line, Rheem called for .6oz of Puron per foot, over 15 feet.

1.5 tons of heating should be plenty for 800-1000 sq ft at those temps unless you live in an old house with lots of air leaks and poor insulation. Did they do a heat loss calculation? If they can't get the system to keep your house warm at outside temps in the high 20s/low 30s, then they undersized the pump and you need to have that discussion with them.

(Edit: The fact that you are getting a 24 degree delta without backup heat suggests the pump is working properly.)

sktn77a,

The tech lowered the fan speed to get the 24 deg split. The delta T might be good, with the lower speed, but now it might not be pushing enough air. Then there's the issue when in AC mode. If the fan speed is to slow, you might end up with a frozen coil. I don't think we know enough the setup and home to know what the problem might be.

Heat pumps have to be sized for the cooling load. The auxiliary heat is supposed to make up the difference.

Do the ducts run in an unconditioned space? Perhaps there is a large duct loss which nobody bothered to calculate.

Thank you all for your comments. The heat pump is 1.5 ton for 800-1000 sq feet area. The air handler is for 2 ton. The heat strip is 7kw. The temperature was maintained - the heat pump just seems to run continuously without stop.

The auxillary heat does not seem to be on right now from reading the thermoset (outside temp is about 35 F). I heard that when the outside temp is between 30 to 47 F, the electric strip will run some. The colder the outside temp, the more the electric strip will run. The ducts from the external heat pump to the main unit on the attic (probably about 15 ft ish) are all new. The refrigerant line is all new. The ducts on the attic (carrying the forced air to the vents and the return air back to the unit) are old - but the technicians checked those and said there were no obvious loss with the ducts.

The first tech said that there was a 4 C difference on the thermoset and changed the thermoset two weeks ago. Last week, when the second tech lowered the fan speed to get more delta T, he said that it is ok for AC mode because naturally cold air comes down and we do not have high ceiling (stand ceiling of 8 ft).

My Mom lives in that wing - she complains that the heat pump ran all night last night (the external temp was about mid 30s and the temperature setting was 68 F). I stayed in that section for over half an hour this morning and the pump was on non-stop. So I do not know if it ran for 1.5 hrs then stop or not (I did not know if it is normal for a heat pump to run continuously for 1.5 hrs). My other units only ran several minutes, then stop for several minutes. They do not ran continuously for a long time at all.

For the adjacent section, I actually set the temp to be 69 F today, 2 F higher than this new unit to rule out the chance that this new unit heats some of the adjacent area. I checked this new heat pump throughout today - it still was always on , I have not seen it to stop (today the external temp is about low 40s, high 30s).

I guess that I will try to get a tool to measure the temperature of the forced air myself, keep a chart and wait for Monday night. If inside the temp is kept at 67 F while the external temp is in the teens on Monday night, even if the heat pump runs continuously without stop, is it normal?

Thank you for all your time and help. Sorry for the long email. I am trying to answer all the questions.

Happy New Year!

Sonya

A Heat pump running 1.5 hours is not a problem, even 2 hours, depending on outside temps. They're built to run non-stop, if needed.

When you say a heat pump only ran several mins then off for several mins, that's a problem. It's not efficient when running short cycles. And a heat pump will work harder when it's heating versus when it's cooling. Like Mike said, heat pumps are sized for cooling.

I'm wondering if you're getting confused when it's running as an AC. When running for 10 mins then stops for 10 mins, in AC mode, that's only 3 cycles per hour, which isn't a problem.

The outside design temperature for the Philadelphia area is 15 degrees. The typical indoor design temperature for winter is 72 degrees. It would be normal for the heat pump to run continuously with the heat strips on under those conditions. Lowering the indoor temp to 67 with an the outside temp above 15 degrees should not cause the heat pump to run continuously in my opinion.

Running continuously means the heat loss of the area and duct work is greater than the heat supplied by the heat pump.

My advice is to set the indoor temperature to what is comfortable for you (70 - 72 degrees is reasonable), and takes notes how long the heat pump runs and if the indoor temperature is maintained for the next two nights. If it is running continuously and can't maintain the temperature then call the installer and tell him this is unacceptable.

Sonya,

We had a some very cold nights. Any updates on how the heat performed? Have you spoken to the installer?

Good morning:

Thank you all for your help. With the heat pump and auxiliary electric strip, the new HVAC heats up to specified temperature (67 F) at these cold nights - the heat pump just ran continuously. Even the tech from the installation company said that the system needs to cycle, not run continuously.

I bought an IR gun from Lowes and measured the temperature myself: when outside temp was in the upper 20s (or low 30s?), the return air temp was 60 F and the forced air from heat pump was 68 F, from auxiliary heating it was about 79 F. Yesterday when the outside air was in the lower 40s, the return air was 67 F and the forced air from heat pump was 80-82.

We actually had the installer to come and fix it the 3rd time last Tuesday (I think that the outside temp was in the low 30s?). He said that the delta T between the two outlets of the equipment (without duct heating loss) was 15F - he wanted it to be 20F. He also said that he did not have a key to access the heating section of the heat pump (new in Rheem equipment). He had to order it. Actually the first technician who came to fix the system said that same thing about needing a key to access the heating section and made a note of it (but he did not order it). The 3rd technician said that he did not understand the note until this time when he needed to access the heat unit himself.

We are actually really worried if the initial installer even had the key to access the heating unit and if he did the super cool and super hot testing (which I specified asked). When we asked Haller Enterprise (the installation company), they said that the original installer had the key because it comes with the equipment and they do not know what happened to the key - that sounds very strange.

So we need to wait for the 4th appointment next Tuesday for them to try to fix the new unit again :-( I am think that if it is not fixed next week, I want to return the unit and ask for the money back - it has been very frustrating to have the new system installed and have to come home from work with these appointments and got disappointed.

Thank you for all your advice and help.

Sonya

In my opinion, you need to set the thermostat to at least 70 degrees to figure out if the heat pump has been properly installed. Once things are resolved you can lower it to 67 if that is the temperature you desire. A 67 degree setting is going to be easier for the heat pump to meet. It may cycle at 67, but run continuously at 70 which in my humble opinion would not be acceptable for an outside temperature above 15 degrees.

I never heard of residential equipment needing a key for access. But even if it did don't you think the service tech would have one in his pocket? I seriously doubt every unit has a unique key. There is something fishy going on.

Does your sales receipt say Home Depot? If it does, then at some point you should get them involved.

A key? You did get the Rheem right? I recently bought and installed a Rheem RP14, which is essentially the same as the RP15, and there was no key.

BTW, I have a generic chart at home that gives ballpark figures to what the delta T should be based on outside temps. I found it online a while back, but can't remember where. It's a good reference point to have. I'll post it later when I get home and find it.

Ok.. Here's what I got for the temp rise. I think the rise is based on temps being taken in the supply and return trunks, not at the registers.

Outdoor Temp...........Indoor Temp Rise (delta-t)
65 deg ........................ 33 deg
60 deg ........................ 31 deg
55 deg ........................ 29 deg
50 deg ........................ 27 deg
45 deg ........................ 25 deg
40 deg ........................ 23 deg
35 deg ........................ 21 deg
30 deg ........................ 19 deg
25 deg ........................ 17 deg
20 deg ........................ 15 deg
15 deg ........................ 13 deg

"I bought an IR gun from Lowes and measured the temperature myself: when outside temp was in the upper 20s (or low 30s?), the return air temp was 60 F and the forced air from heat pump was 68 F, from auxiliary heating it was about 79 F. Yesterday when the outside air was in the lower 40s, the return air was 67 F and the forced air from heat pump was 80-82."

not what you wnt to hear, but supply temps are very low and points to a refrigerant charge problem. Until you get this corrected, I would expect system to run continuously. I would not accept this situation and would be complaining to installer to fix or remove the equipment.

IMO

Thank you so much for all your help. The table could be very useful - I will talk with the installer about the delta T when he comes to fix the problem this afternoon. Does "not at the register" mean after the duct loss (from the return air vent and the force air out vent)? Also, if this is a refrigerant charge issue, could adding more refrigerant solve the problem, or does the installer have to recharge the system again? Is it fixable after installation? Thanks.

One more questions: how much the delta T should be at the register? Thanks.

Register delta T doesn't mean squat, unless they did duct work. If you have bad duct work, it is what it is until you get that fixed.

As for checking Delta T, I have one temp prob before the blower and the other temp prob about a foot past the evap coil. When checking, make sure your Aux heat is OFF.

If it's a charge issue, it could be to low or to high. Charging when outside temps are low can get tricky, so many do it by weight (You'll need to have all the refrigerant recovered then it'll need to be put back in by weight ... You need to account for line set length). Many times, a tech will come back out when outside temps get to about 70 deg F to check the charge.

Good Luck!!

Thanks. Just to clarify: do the delta T in the table mean the delta T between "the return air vent" and "the supply air vent"? Or do they mean the delta T between supply air and return air right in/off the equipment on the attic?

I went to Rheem website and could not find the Delta T type of specifications - I want to know if the equipment is operating according to spec or not. Is there somewhere I can check if the equipment is operating according to spec? Thanks.

If you want to know how your new heat pump is performing, you want to do it right at the equipment, in your attic. Take temp before it enters and the other temp right after the Evap coil.

If you took the temps from where the vents are located (rooms, hallways), you might think your new system is bad, but it might be your duct work. If you have leaky ducts, especially ones that might go through unconditioned areas, you really won't know how your equipment is performing.

Haller Enterprise came yesterday afternoon. He had the correct key and measured the refrigerant level from the heating side and said that he got a 9. He also measured the temperatures on the attic and got a delta T of 20 F. He was happy with the refrigerant level. He did say that the auxiliary heating strip was too small - when the auxiliary heating was on, he could only get 8 F temperature rise.

He patched the hole behind the thermostat where the wires come and said that there might be some cold current affecting the thermostat reading. He said that there is nothing he can do - he said that the machine works normally. But he could not explain why the heat pump does not cycle normally.

He tried to tell us that the HVAC meets the temperature setting (currently 67 F) and it was wired correctly. So we are back to square one. It just does not run normal for me - the thermostat says that the temperature reaches the setting, but the heat pump just continues to run and run. It runs continuously at lower outside temp (in the 30s), very limited stops (when outside temp in the 40s - the heat pump would run and run and occasionally it will stop for about one minute). I can only see clear cycles when the outside temp in the 50s. I worry how long will the system last and how high the electric bill would be if it does not run normally. I do not know if we should return the system or not. Thanks.

What will raise your electric bill is if your Aux heat (electric heat strips) are running. A delta T of 20 is in the normal range in the low 30s.

I wonder if you're house is really leaky or it's your duct work. Do you know what the split was, at the vents, when the split was 20 at the air handler? If you know that value, you can see how much heat you're losing to your duct work. If you're not losing anything in the duct work, then I would say your house is leaky.

You might want to contact your electric company to see if they offer a free energy audit. A thermal imaging camera can show you where you're losing heat from your home... assuming it's a leaky house.

BTW, I'm assuming you don't have a bad thermostat since you're not saying the temp is rising above your set point...

"I do not know if we should return the system or not."

You will know the answer to this question when you get your next electric bill.

Good morning: This week it has been very cold (in the 20s and 30s). The HVAC just ran day and night, non stop. No cycle at all.

The Haller technician said that that section is leaking. So we did an experiment and turned the system off. In 1.5 hrs, the temperature dropped one degree (from 68 to 67) while the outside temperature was 23 F. My sunroom (has 7 windows) has a heatpump and auxiliary heating as well. We turned off that system as well - the temp dropped from 72 to 66 in one hour and 20 minutes. The sunroom HVAC gives good heat and cycles normally - when it is cold outside, it runs longer, but still cycles. So I do not think that the non-stop running is due to leaking.

Is it possible that this unit has a bad computer chip or the setting is wrong somewhere? Otherwise, the thermostat says that the temp has reached the setting but why it does not stop.

I tried to call Haller and asked to return the unit. They said that the unit is running properly - the sales person tried to say that it is normal to run continuously when it is at 20s or 30s, but then what if it is Minisota area，then the HVAC would not stop for many months at winter then? I regretted so much to have picked Haller and this HVAC system - so much anxiety and time away from work.

Any advice would be appreciated. Thanks.

Sonya