Amana S Series Inverter System Heat Pump

[DuckRyder]

Does anyone have one of these and if so do you like it and has it been any trouble.

To make a long story shorter we are looking at a lower capacity unit to condition only the upstairs instead of the 15ish year old 4 ton unit. which conditions both up and down stairs but very unevenly. (there is now a mini split to handle the downstairs)

To me the compactness and quietness are big selling points and also we are being told we will save quite a bit on energy. Additionally that the unit controls humidity and we wont miss the dual fuel furnace.

Any experience?

 

[Cujet]

I don't know the unit, so can't sing it's praises. However, be cautious about energy savings claims. The SEER rating on variable speed products is also variable, and they often publish fantastic numbers that are achieved only when there is a mild temp differential between outside and inside. At full output, (with a high temp differential between outside and inside) they are often no different when compared to today's quality equipment.

As always, it takes a certain amount of BTU to create a temperature differential between outside and inside.

If you are replacing a natural gas furnace with a heat pump, It is entirely possible your utility bills will not go down. If you have oil or expensive propane, lower costs are possible. And if you are using resistance heat strips excessively in cold weather, there can be significant savings.

A heat pump for very cold weather simply speeds up the compressor to warp 9 (a bit of a joke here of course). In reality the way they make that work is by greatly oversizing the compressor. Running it slower during mild days via the inverter. A 2.5 ton cold weather heat pump will have a 5 ton compressor.

I like this type of design, and it can be effective.

 

[Cujet]

Maybe on a bit of a tangent, but here is a neat chart that shows a heat pump for water (air is the same), it illustrates how COP or efficiency drops with temp, despite having the same output. Again, the output is maintained by speeding up the compressor.

Clearly, if outside air temps are very low, it's not much more efficient than resistance heating.

 

[DuckRyder]

I should more accurately say that the furnace provides auxiliary heat vs heat strips, it only runs when it is very cold, which is not often. I feel like 4th gas is fairly expensive though.

The new unit will have heat strips and we are told due to the humidification properties they will work as well as the gas heat.

 

[PWMDMD]

I don't know the unit, so can't sing it's praises. However, be cautious about energy savings claims. The SEER rating on variable speed products is also variable, and they often publish fantastic numbers that are achieved only when there is a mild temp differential between outside and inside. At full output, (with a high temp differential between outside and inside) they are often no different when compared to today's quality equipment.

That’s interesting and I don’t much about how SEER is measured. I can say I replaced a 4-ton American Standard installed in the early 1990’s with a Bosch IDS 2.0 4-ton SEER 20 heat pump a few years ago. The first summer we were here with the old system it was hot and with the thermostat set on 72F the electric bill was $700 that month. Last month was easily hotter and really humid and with the thermostat set on 68F, the electric bill was $320. The unit can also maintain a 26F delta between outside air temp and inside air temp. Lastly, I’ve used the heat pump all the way down to 5F just to see if it would work and while it ran constantly, it was able to maintain the inside temp. I now use the heatpump down to 15-25F depending on the price of oil (it’s a dual fuel setup) because we have relatively cheap electricity from a municipal power company.

 

[DuckRyder]

The old 4 ton unit is 14 SEER, (so ~ 13.4 SEER2) The new 16.3 SEER2. EER2 8.7

 

[Fitter30]

The higher the seer the more knowledgeable the service person has to be. Unit that is 20+ seer is computer control from electronic expansion valves (hp) to variable speed compressor. Critical charged. Service person will have to have a laptop with the newest up to date software to look at all the sensors and speed of motors. The contractor has to of made the commitment to have hopefully two service people factory trained at least once a year. Being factory train give the service person a tool. The phone number and the right person to talk with if there is a odd problem.

 

[KJSmith]

Will this unit be the new refrigerant or the older refrigerant?

Not sure if it would make a difference to me, but I might want to avoid buying a system with the older refrigerant depending on the phase out dates.

 

[KJSmith]

Does it run heat to rewarm air when it is running just for humidity control?

 

[SubieRubyRoo]

Maybe on a bit of a tangent, but here is a neat chart that shows a heat pump for water (air is the same), it illustrates how COP or efficiency drops with temp, despite having the same output. Again, the output is maintained by speeding up the compressor.

Clearly, if outside air temps are very low, it's not much more efficient than resistance heating.

I agree with everything except your very last statement. Even at -10F, a 1.5COP is still a significant savings over a nearly 100% efficient electric furnace.

If I was in that market (I’m in propane, looking at ground source heat pump w/desuperheater for DHW), or even what I’m in now, more attic insulation & sealing current leaks is always going to improve performance of any system. In my last place that was a 26yo heat pump with electric backup, the $300 in cellulose insulation paid back almost 2x in its very first winter, and that was a milder winter than the one before. Going from R-19 batts to R-60 really helps things out!

 

[CDX825]

The newer systems with inverter driven compressors are nice. This unit you are looking is basically a mini split condenser with and air handler. It should work well.

 

[Cujet]

I agree with everything except your very last statement. Even at -10F, a 1.5COP is still a significant savings over a nearly 100% efficient electric furnace.

Correct, resistance strips are only 100% efficient, and not 150%+ like heat pumps are.

However, that heat pump can be many thousands of dollars, even $10's of thousand of dollars. There is a capital cost to the things, as they have a limited lifespan and expensive repair costs.

$700 parts and $400 labor charges are the norm here. That goes a long way towards occasional low efficiency heat

 

[SubieRubyRoo]

Correct, resistance strips are only 100% efficient, and not 150%+ like heat pumps are.

However, that heat pump can be many thousands of dollars, even $10's of thousand of dollars. There is a capital cost to the things, as they have a limited lifespan and expensive repair costs.

$700 parts and $400 labor charges are the norm here. That goes a long way towards occasional low efficiency heat

Completely agree. But when you’re in an area with more than 2 dozen heating days (jealous! ) over the lifespan of an electric furnace vs heat pump, the operational costs of the furnace will likely dwarf that of the heat pump.

In many colder environments, another “perk” of the heat pump vs standard AC is that since the outdoor unit runs thru winter, it generally reduces many of the issues AC units only can see like corrosion.

Like I said, my ultimate goal is to do an open loop ground source heat pump with WaterFurnace; I’ve got plenty of land to do a loop big enough to cover all HVAC & domestic HW needs. The issue is since 2020, the quote to do it has risen 40% and now would be over 30% of what I paid for 1800SF, a garage & barn on 3.1 acres in 2019. Operational costs would drop probably 90%+ vs my current propane/AC unit, but even then the break-even is 15-17 years out depending on propane prices. One neat idea would be to drop a ~6kW array and a PowerWall or 2 and tie it into the geo system for another $15k or so, and then have that all at essentially zero cost (other than maintenance) for the next 25 years. By then it will be my heirs’ problem

 

[DuckRyder]

Will this unit be the new refrigerant or the older refrigerant?

410A like the mini split

Not sure if it would make a difference to me, but I might want to avoid buying a system with the older refrigerant depending on the phase out dates.

Does it run heat to rewarm air when it is running just for humidity control?

I'll ask if i can manage not to sound like an idiot.

If understand correctly due to the number of vents, size of the returns and airflow the current unit is even more inefficient than if it was properly sized. There's also an issue with the way some vent were run off the trunk line the quote includes fixing all this. The owner of the HVAC company said most of the houses in this area have improper ducts because no one really knew what they were doing in the 70's.

This is the unit:

https://www.amana-hac.com/products/heat-pumps/aszs6-s-series

 

[DuckRyder]

Also this.

 

[KJSmith]

Looks pretty interesting.

It has 3 different ways to control humidity..... but it doesn't look like you have a setting for humidity.
I wouldn't think that would be necessary.... that's what had me curious.

On some high-end commercial units, they run the compressor so much to remove humidity that it has to run heat to keep temperature set point.
This unit does not appear to do that... you can adjust the way it removes humidity and to a certain degree how much.

Looks like it has a decent warranty also.

I'm not familiar with the inverter compressors and need to read up on them....I understand the principal.
Inverter compressor failures were quite common in some of the foreign made refrigerators.
I know several people who were given their money back on Samsung refrigerators that were deemed non repairable.

Heat pumps...well actually air conditioners also, remove heat....they do not cool.
In summer they remove heat from the house and reject it outside.
In winter, they try to remove heat from outside and reject it inside.
The colder it is outside...the less heat they can pick up.

I've only lived in one house with one.....and that was a long time ago.
It just didn't put out air as warm as a traditional furnace.

 

[CDX825]

Does it run heat to rewarm air when it is running just for humidity control?

Doubt it. Thats not a very common thing in residential setups.

 

[KJSmith]

Doubt it. Thats not a very common thing in residential setups.

Correct.
I looked through the info he provided and made comments above.

 

[DuckRyder]

Well we ordered this. Unfortunately it is cooling off so it will probably be a year before i know if there is any savings.

 

[Donald]

Does anyone have one of these and if so do you like it and has it been any trouble.

To make a long story shorter we are looking at a lower capacity unit to condition only the upstairs instead of the 15ish year old 4 ton unit. which conditions both up and down stairs but very unevenly. (there is now a mini split to handle the downstairs)

To me the compactness and quietness are big selling points and also we are being told we will save quite a bit on energy. Additionally that the unit controls humidity and we wont miss the dual fuel furnace.

Any experience?

It will only reduce humidity when it's cooling. So if your house is humid but does not need much cooling then it will not do much to reduce the humidity.

Many people connect a dehumidifier to the HVAC and use the fan in the HVAC and dehumidifier to reduce the humidity in the house without actually running the A/C.