Inverter heat pump Central ducted systems

[gregs]

I currently have a 4 ton WSHP that operates off an open loop well system. Its going on 20 years old and still works fine. But thinking about options for the future. One of the issues / problems with a conventional heat pump system is locating a spot outside for the condenser unit mostly because they are so big and ugly (wife says). I started looking into the inverter units mostly because the outdoor unit is much more compact and less obtrusive. WIth the high seer ratings I am thinking the efficiency may actually be better than the older WSHP and well operation now.

Looking for any feedback specifically regarding the inverter units that use a typical ducted style evaporator indoor unit. I want to keep my current duct system and not use the mini split head units. I have a location that would work for the outdoor unit that I can get power to and the refrigerant lines. Curious as to the life expectancy, how well they work compared to a conventional heat pump, drawbacks, etc.

 

[theoldwizard1]

WIth the high seer ratings I am thinking the efficiency may actually be better than the older WSHP and well operation now.

Simple thermodynamics says that a constant temperature heat sink/source (the well) will always beat a variable temperature heat sink/source (outside air). Maybe not all of the time, but certainly in extreme hot/cold weather.

 

[Jackfre]

TOW1. Is right on this but in addition to a 20 yr old HP you have a 20 yr old “system.” You have to throw pumping cost into the mix too. Yes you have a constant cop with the water. Where do you live?

 

[danski0224]

I started looking into the inverter units mostly because the outdoor unit is much more compact and less obtrusive.

Really only true for mini splits.

Not all mini split condensers can run a conventional split evap.

WIth the high seer ratings

Only true for mini splits. SEER includes ductwork, which most mini splits do not hsve.

I am thinking the efficiency may actually be better than the older WSHP and well operation now.

"Thinking" = assuming in this case.

Verify published specs.

 

[gregs]

Just for a quick view, this is what I was looking at. Havent gone done the rabbit hole yet...

https://hvacdirect.com/4-ton-16-5-seer2-mrcool-central-ducted-hyper-heat-2nd-gen-heat-pump-split-system-r454b-central-48-hp-c-230b00-o-mvp-48-hp-muah-230a00-o.html?utm_term=199040&utm_source=google&utm_medium=cpc&utm_campaign=Heat%20Pump%20%7C%20Shopping%20%7C%20Unitary%20%7C%20Branded%20%7C%203%20-%20Low%20%7C%20MRCOOL&utm_content=MRCOOL%20%7C%20Inverter%20%7C%204.00%20Ton%20-%2048k%20BTU&utm_adgroupid=161919885729&utm_term=&gad_source=1&gad_campaignid=21036260622&gclid=Cj0KCQjwp9vTBhCWARIsANaUrjsnJUcRTs82GrIGhcgpJYiqhWGwCbXc9vyW8MDSgAs55TkuIb73G0YaAv6HEALw_wcB

 

[WildBill]

Just for a quick view, this is what I was looking at. Havent gone done the rabbit hole yet...

https://hvacdirect.com/4-ton-16-5-seer2-mrcool-central-ducted-hyper-heat-2nd-gen-heat-pump-split-system-r454b-central-48-hp-c-230b00-o-mvp-48-hp-muah-230a00-o.html?utm_term=199040&utm_source=google&utm_medium=cpc&utm_campaign=Heat%20Pump%20%7C%20Shopping%20%7C%20Unitary%20%7C%20Branded%20%7C%203%20-%20Low%20%7C%20MRCOOL&utm_content=MRCOOL%20%7C%20Inverter%20%7C%204.00%20Ton%20-%2048k%20BTU&utm_adgroupid=161919885729&utm_term=&gad_source=1&gad_campaignid=21036260622&gclid=Cj0KCQjwp9vTBhCWARIsANaUrjsnJUcRTs82GrIGhcgpJYiqhWGwCbXc9vyW8MDSgAs55TkuIb73G0YaAv6HEALw_wcB

I would recommend getting your equipment from these guys as they have really great support and are good dealing with on warranty stuff. I am looking at replacing my 20+ year old conventional forced air setup with something like this as well. https://iwae.com/shop/4-ton-16-5-se...d-generation-multiposition-r454b-ha26283.html

 

[gregs]

I would recommend getting your equipment from these guys as they have really great support and are good dealing with on warranty stuff. I am looking at replacing my 20+ year old conventional forced air setup with something like this as well. https://iwae.com/shop/4-ton-16-5-se...d-generation-multiposition-r454b-ha26283.html

My link was just a quick search to post. I havent really looked into brands and such yet. Also with the newer / different refrigerants available, thats another consideration. It seems like the 410 stuff has a lot of issues and seems to die after 10 years. Not sure if the newer refrigerants are any different / better.

But yea, thats generally what I am thinking about.

 

[gregs]

TOW1. Is right on this but in addition to a 20 yr old HP you have a 20 yr old “system.” You have to throw pumping cost into the mix too. Yes you have a constant cop with the water. Where do you live?

I am in Florida. Its sorta a function of age of both the unit and well equipment. Not to mention we are coming out of a drought now, so the water can be a potential issue in the future. I am not knocking the efficiency of the WSHP but more the future as we are going to be here for at least another 20 years.

 

[theoldwizard1]

Only true for mini splits. SEER includes ductwork, which most mini splits do not have.

Excellent point ! Mini-splits will always win compared to central systems for this reason.

 

[theoldwizard1]

I am in Florida.

If I lived in FL, personally I would stick with water source.

 

[Two Door]

Here is one tesimonial (very positive) - over at the "other place". No history for you, as it's been newly installed, but interesting regarding current performance.

 

[fitter30]

There is no way that air cooled can compete with geo. Heating 45° water has more heat than 0° air. Cooling 50° water has less heat rhan 100° air. How often did the geo water coils have to be acid cleaned?

 

[pima67]

As for big and ugly, landscaping with bushes and or decorative wall could make her happy. Our AC compressors are enclosed by 6 ft high walls with gates next to building.

 

[gregs]

There is no way that air cooled can compete with geo. Heating 45° water has more heat than 0° air. Cooling 50° water has less heat rhan 100° air. How often did the geo water coils have to be acid cleaned?

Average water temp is 72-74 year round. I have cleaned the coil a couple of times over the years. Again I am not knocking the geo, just thinking about the next 20 years.

 

[mm08822]

Average water temp is 72-74 year round. I have cleaned the coil a couple of times over the years. Again I am not knocking the geo, just thinking about the next 20 years.

Where are you located that delivered water temp is 72-74F?

 

[gregs]

North Florida. The springs and aquifer are that temp all year.

 

[Two Door]

I would assume the inverter condenser would act no differently powering a ducted indoor setup than it would with individual heads, and apparently they work well across the world. One obvious vulnerability is the inverter boards, which can be taken out by lightening and voltage spikes, especially if they have no intentional protection.

 

[jlv03]

Is there a room or two that could benefit from a minisplit?

I say run the geothermal until failure, and then make the decision. Meanwhile, no harm in experimenting with a minisplit to heat/cool a certain part of the house.

 

[pembol]

We have a closed loop geo system for the house and a high efficiency air to air minisplit for the garage. The minisplit has been great, but there is no way I would trade the geo system for a minisplit.

It has been really hot the last few weeks, and the geo system is running with a COP around 6, whereas the minisplit has a COP around 3-4. While the minisplit is doing really well, the geo system is almost twice as efficient. That would be a lot to give up. Seeing you already have the infrastructure, why wouldn't you replace your geo system with another geo system when the time comes?

 

[gregs]

The WSHP is a r22 tank that just keeps trucking along. I am more concerned with the well equipment and future water supply. I can get by without ac for a few days to get it fixed, but being without water really *****. I have looked into some type of closed loop changeover but the costs to do that is pretty high. I am constantly analyzing the cost of equipment/maintenance to the cost of power to see what seems to make the best financial sense.

My parents had their old (40+yo)) air to air replaced about 5 years ago with a Goodman 18seer unit. It works really well, however the outdoor unit is huge.

The inverter outdoor units are all over the place around here (houses and businesses), not sure how many are head units vs central systems.

The electronic factor is probably my biggest concern with potential damage from lighting and power surges / brown outs. I need to see what type of protection they have and what can be added. I would probably look into purchasing spare control boards at the time of purchase to have on hand if they where reasonable.

There really isnt a good location to put a big outdoor unit that isnt in front of a window. I have identified 2 locations that I could install the inverter style unit that would work.

 

[gregs]

We have a closed loop geo system for the house and a high efficiency air to air minisplit for the garage. The minisplit has been great, but there is no way I would trade the geo system for a minisplit.

It has been really hot the last few weeks, and the geo system is running with a COP around 6, whereas the minisplit has a COP around 3-4. While the minisplit is doing really well, the geo system is almost twice as efficient. That would be a lot to give up. Seeing you already have the infrastructure, why wouldn't you replace your geo system with another geo system when the time comes?

Not sure where you are located. We have friends in N. Georgia that built a huge house that had two closed loop GEO systems installed. They had constant issues and seemed like the ac guy was out there constantly. Finally one suffered some type of big problem and they ended up swapping it out for an air to air unit due to costs. They had trench style loops.

 

[danski0224]

I need to see what type of protection they have

None.

 

[danski0224]

They had constant issues

Proper installation is key.

 

[gregs]

None.

There will be something, just how robust is the unkown.

 

[danski0224]

I put external surge protection on all installs now.

 

[gregs]

Proper installation is key.

That goes without saying.... But there are a lot more components and maintenance needed than a conventional air to air system. They are not able to do any of that on there own, so it became costly.

 

[theoldwizard1]

North Florida. The springs and aquifer are that temp all year.

Weird ! I have never heard of ground water (below 10' deep) being above 60F !

 

[theoldwizard1]

There really isnt a good location to put a big outdoor unit that isnt in front of a window. I have identified 2 locations that I could install the inverter style unit that would work.

If you are going this way, make sure there is about 6' of unobstructed space on the front and both sides of the outdoor unit. Shrubbery is fine if you leave the space. Look for a place with minimal direct sunlight.

 

[theoldwizard1]

The electronic factor is probably my biggest concern with potential damage from lighting and power surges / brown outs. I need to see what type of protection they have and what can be added. I would probably look into purchasing spare control boards at the time of purchase to have on hand if they where reasonable.

Whole house lighting, power surges / brown outs protection for the whole house is a good idea.

If you buy a well known name brand unit, don't worry about spares

 

[gregs]

I put external surge protection on all installs now.

What do you use?

 

[danski0224]

Intermatic AG3000.

 

[Jackfre]

Back in the 70’s I installed WSHP’s that we fed off solar heated swimming pools. Being in FL your problem should you do this, is overheating the pool in cooling mode. We had one out here where we had to install a cooling tower as we overheated the pool. If you have a pool you could make a hybrid system too. Gets a bit complicated in the controls and equip, but an option.

From a straight redundancy standpoint a single high seer minisplit is a good plan

 

[gregs]

Back in the 70’s I installed WSHP’s that we fed off solar heated swimming pools. Being in FL your problem should you do this, is overheating the pool in cooling mode. We had one out here where we had to install a cooling tower as we overheated the pool. If you have a pool you could make a hybrid system too. Gets a bit complicated in the controls and equip, but an option.

From a straight redundancy standpoint a single high seer minisplit is a good plan

I do have a pool and did have this idea and went down the rabbit hole years ago. When I built the pool I had an extra loop installed to make it easy to tap into. Had even found a company that had a small cooling tower and another company with a SS heat exchanger that could handle the salt water and chlorine of the pool. So your basically heating the pool in the summer and cooling the pool in the winter which is exactly the opposite of what you want to do for pool use. By the time I figured out what it would take to do this and all the equipment (pump, plumbing, automation, etc.) verses the payback I decided against it as an open loop well is the least of all that.

 

[pembol]

Not sure where you are located. We have friends in N. Georgia that built a huge house that had two closed loop GEO systems installed. They had constant issues and seemed like the ac guy was out there constantly. Finally one suffered some type of big problem and they ended up swapping it out for an air to air unit due to costs. They had trench style loops.

We are in CO, with vertical wells. It has been ticking away for all our heating and cooling for the past 3 years with zero issues whatsoever. Sounds like the instal was not done right at your friend's house.

 

[aggie113]

Recently installed a ducted heatpump to replace a conventional compressor/gas burner setup. The inverter is taller but less deep than the old compressor but far from invisible. The interior blower unit was sized/sold as a combo and rated for SEER21. I'm sure I'm a bit less than that as nothing is perfect but I do have metal ducts (though they do run through the attic) but certainly higher than the old system that had the same constraints. If you can get a setup that pairs a tested setup of the compressor and air handler you can aim for a high SEER system. Mine is a Mitsubishi hyperheat setup.

 

[gregs]

Recently installed a ducted heatpump to replace a conventional compressor/gas burner setup. The inverter is taller but less deep than the old compressor but far from invisible. The interior blower unit was sized/sold as a combo and rated for SEER21. I'm sure I'm a bit less than that as nothing is perfect but I do have metal ducts (though they do run through the attic) but certainly higher than the old system that had the same constraints. If you can get a setup that pairs a tested setup of the compressor and air handler you can aim for a high SEER system. Mine is a Mitsubishi hyperheat setup.

Must be the efficiency difference? I have found that a number of 4 ton units use a single condenser and then some have a double stacked unit.

 

[cpakalolo]

Just for a quick view, this is what I was looking at. Havent gone done the rabbit hole yet...

https://hvacdirect.com/4-ton-16-5-seer2-mrcool-central-ducted-hyper-heat-2nd-gen-heat-pump-split-system-r454b-central-48-hp-c-230b00-o-mvp-48-hp-muah-230a00-o.html?utm_term=199040&utm_source=google&utm_medium=cpc&utm_campaign=Heat%20Pump%20%7C%20Shopping%20%7C%20Unitary%20%7C%20Branded%20%7C%203%20-%20Low%20%7C%20MRCOOL&utm_content=MRCOOL%20%7C%20Inverter%20%7C%204.00%20Ton%20-%2048k%20BTU&utm_adgroupid=161919885729&utm_term=&gad_source=1&gad_campaignid=21036260622&gclid=Cj0KCQjwp9vTBhCWARIsANaUrjsnJUcRTs82GrIGhcgpJYiqhWGwCbXc9vyW8MDSgAs55TkuIb73G0YaAv6HEALw_wcB

If you are going to diy, I would recommend the unit you already selected. You will have to buy and attach some duct to them, I think that's why you selected it. Often, in a shed, I will only do a plenum on the discharge to get the air up and gain velocity pressure, then ran in flex to the vents. The return I always use is a Space guard filter screwed directly to the bottom with a stand. The dust in a shop is what is bad on coils. A space guard filter will leave a very clean coil behind it and you only have to change the media once a year.

 

[aggie113]

Must be the efficiency difference? I have found that a number of 4 ton units use a single condenser and then some have a double stacked unit.

My guess is when the fan(s) are spinning slower it's easier to have two fans pushing air past a thinner array than one fan past a thicker array.

 

[cpakalolo]

We are in CO, with vertical wells. It has been ticking away for all our heating and cooling for the past 3 years with zero issues whatsoever. Sounds like the instal was not done right at your friend's house.

It's open loop. 99% of them fail in a couple years. You can't even get rebates for them. Wells or horizontal loops work. A pond or lake sometimes works.

 

[gregs]

Our house was built in 1981 with an open loop WSHP. I bought the house in 1998 and replaced the WSHP about 3 years later. I only replaced it because it was 20yo at that point and my friend was able to get me a new Trane unit at a incredibly reduced price. So its been chugging along for about 25 years now. Remember the original one? I didnt get rid of it, I put it in storage and eventually my brother took it to his place to use in his shop. He put casters on the bottom and made a pigtail to plug into a welder outlet. Then added some water valves and used garden hoses for the connections. Heck he even loaded it up and took it to a friends shop when he went to help him change the clutch in his C6.