Half of House Connected to Heat Pump, Other Half Doesn't Have Any Heating or Cooling

[newathvac]

Hello everyone,

I'm new at HVAC, so I apologize if anything I say isn't correct or if I ask some questions that are extremely basic.

I'm looking for some solutions regarding my current heating and cooling situation. The house is from the 1940's, and has a newer addition. The addition has a Goodman heat pump self contained packaged unit, connected to natural gas, and is 3 ton, 69,000 BTU (according to my Google searches). The old part of the house has duct work underneath, and has an old heater that is not in use connected to it. The old part of the house is 500 - 1,000 square feet, and the whole house is 1,900 - 2,000 square feet. I was told the duct work would be difficult to connect from the Goodman heat pump because there are walls that they would need to go through. I was also told that the duct work under the old part of the house would need to be replaced because it is old and can't handle the 3 ton unit.

I'm looking for the best (and cheapest) way to get heating and cooling on the other side of the house. I prefer to have one unit for the whole house, instead of needing to maintain two units, but it might be too costly to get the Goodman heat pump connected.

I've been looking into the Ductless Mini-Split units from Mitubushi and Fujitsu. Do you think this would be a good option? I've heard they're more efficient that most other options. Is that true?

Please let me know what you think would be the best (and cheapest) option for my situation.

Thank you.

[crmont]

A ductless system is a good choice unless your in a cold climate.

[carmon]

nothing wrong with 2 units.... one quits you still have some heat

[newathvac]

Thank you for your replies. I really appreciate it.

I have a few more questions.

1) Do you think the Ductless Mini-Split is going to pay for itself with energy savings more than a cheaper 25,000 BTU Window Air Conditioner and 16,000 BTU Heater would?

2) Also, if the Goodman eventually stops working, would it be best to get that replaced with another heat pump, or would it make more sense to use a Ductless Mini-Split for the whole house?

I really like the idea of the Ductless Mini-Split but I haven't read much about people using them for the whole house system, I have been reading about people that use them for certain areas. So, I'm thinking they're efficient, but just for people that cannot use a regular system. If they were the most efficient for the whole house I would think more people would be using them.

3) In the long run, would it be better to get a Ductless Mini-Split or would it be best to get new duct work under the old part of the house and use a second regular heat pump?

I'm really looking for what is cheapest and what would be best in the long run.

Thank you!

[carmon]

whats cheapest and best will be different.... ductwork always better in my opinion....wonn't be the cheapest though

[newathvac]

Thank you for your replies.

We did decide on getting the Ductless Mini Split, by Fujitsu. I'm looking forward to getting it installed.

Thanks again!

[jtrammel]

Thank you for your replies.

We did decide on getting the Ductless Mini Split, by Fujitsu. I'm looking forward to getting it installed.

Thanks again!

Good choice, the technology used in mini-splits is where the hvac industry is headed in The near future. The heat losses/gains and leakages of ductwork greatly decreases the rated efficiency of ducted equipment also. If I were building a new house I would put in minisplit heat pumps.

[motoguy128]

IF i could have done my HVAC system (PO installed 2 new furnaces), I would have installed either zoned mini splits or a water to water geo with individual fan coils in each zone, but either way, no distributed airflow in large ducts. I would have kept my radiators, but converted from steam to hot water.

SEER rating is nice, but the next step in savings is only heating or cooling hte spaces you occupying during certain times of the day. SO at night, no need to condition the downstairs or bedrooms your not using. In the mroning, if you only use a kitchen, why heat up hte whole downstairs, why not just warm the kitchen.

You can also accomplish much of the same with a zone system if you have large enough ductwork in each zone.

FYI - ANY wall can be opened to install ductwork. .. it's just a matter of cost.

The 3 ton 69k unit in most climates and homes in the US, is plenty for a 2000sqft home, especially if zoned. INSULATE THAT CRAWLSPACE and ductwork located in it REALLY REALLY WELL !!! while your at it.

[vstech]

... you have a 3 ton package heat pump with 69KBTUH heat... I'm guessing you calculated the strips into the heat total?
and it's heating/cooling 500-1000square feet addition... (kinda a large range there)
where do you live? that's HUGE cooling for the square footage covered.
I don't think it would be large enough to handle the 3000Sqft of the entire house, but it might.
ductless is a good choice, be sure and seal up all the ducts from the old system, and tighten up the house as well. sealing the crawlspace is wise, as is insulating the walls and the attic!

[newathvac]

Good choice, the technology used in mini-splits is where the hvac industry is headed in The near future. The heat losses/gains and leakages of ductwork greatly decreases the rated efficiency of ducted equipment also. If I were building a new house I would put in minisplit heat pumps.

That is a question that I had, if they'd be recommended for a new construction. Is anything going to be done about the line going up the side of the house? In my case, it looks fine, but I would think that some people wouldn't choose to get a mini-split because of it. Is it possible to put it in the walls of a new construction? I'm just curious.

IF i could have done my HVAC system (PO installed 2 new furnaces), I would have installed either zoned mini splits or a water to water geo with individual fan coils in each zone, but either way, no distributed airflow in large ducts. I would have kept my radiators, but converted from steam to hot water.

SEER rating is nice, but the next step in savings is only heating or cooling hte spaces you occupying during certain times of the day. SO at night, no need to condition the downstairs or bedrooms your not using. In the mroning, if you only use a kitchen, why heat up hte whole downstairs, why not just warm the kitchen.

You can also accomplish much of the same with a zone system if you have large enough ductwork in each zone.

FYI - ANY wall can be opened to install ductwork. .. it's just a matter of cost.

The 3 ton 69k unit in most climates and homes in the US, is plenty for a 2000sqft home, especially if zoned. INSULATE THAT CRAWLSPACE and ductwork located in it REALLY REALLY WELL !!! while your at it.

Is it costly to insulate the craw space? Also, the duct work on the addition is in the wall. It would sound costly to insulate that because I would think they would need to open up the walls. What about the attic? I don't think there is much, if any, insulation there. Is it costly to insulate, and is it really worth the money? Do you think I'll get my money back in energy savings even with the mini-split?

... you have a 3 ton package heat pump with 69KBTUH heat... I'm guessing you calculated the strips into the heat total?
and it's heating/cooling 500-1000square feet addition... (kinda a large range there)
where do you live? that's HUGE cooling for the square footage covered.
I don't think it would be large enough to handle the 3000Sqft of the entire house, but it might.
ductless is a good choice, be sure and seal up all the ducts from the old system, and tighten up the house as well. sealing the crawlspace is wise, as is insulating the walls and the attic!

I thought it was a heat pump from what I saw on Google when typing in the model, but I had a couple people tell me that it isn't a heat pump and uses gas. From a recent calculation, I believe the addition is closer to 1,500 square feet. The other part of the house is 500 square feet, possibly a little less. The entire house is approximately 2,000 square feet (not 3,000).

I'm worried the insulation will be costly, especially if they need to open up the walls in the new addition.



We have the Fujitsu 15RLS2 installed! I'm still trying to learn how it is working. It seems like it is running outside a lot. Sometimes the fan is blowing hard outside, and sometimes it is almost silent. At times I'll hear an electric sound, I don't know if that is the compressor or if that is a motor making the fan blow. Every once in a while it will turn off completely, but that is only for two or three minutes, and it will come back on. I've been worried that it is running too much because it isn't enough power for our house, but we did have the Manual J done and were told this is the correct unit for us.

Is it normal to run almost all the time outside? I read about an "Inverter" technology, I don't know if that has anything to do with it. We just have one air handler inside, so it's not like there are other units running, it is just the one. I would think it would shut down every twenty minutes or so, but it just keeps running and shuts down once every hour or two.

A few minutes ago the green light started flashing, it wasn't blowing any air, I went outside and the fan wasn't running but it was making a noise. Then, the green light stopped flashing, and there wasn't a noise outside (it had shut down). Then, a few minutes later it started again. I don't know if that is normal and it reached the desired temperature or if something was wrong. I thought it could be in defrost mode but it is only 38 degrees outside and there isn't any ice anywhere.

I'm looking forward to your replies.

Thank you.



EDIT: I've also noticed that sometimes it is blowing hot air inside, and other times it's just warm air. I just walked outside now and the outside unit is loud again.

[newathvac]

I don't see the option to edit my post above.

I figured out that the reason why it shut off and was flashing a green light was because nobody was moving for 20 minutes, and it has a feature to shut off and adjust the temperature until somebody comes back in the room. We got up right away, and I think it was flashing because it has a safety feature where it doesn't restart until a few minutes go by. So, when the time when by, it started again.

I'm really wondering why it seems like it is running almost constantly. At times it will be hot, and others it will just be warm, but the unit outside is always running (whether it be a fan spinning almost silently or making some noise, or loud noises). I'm worried it is running to much but I probably just don't understand how it works yet.

[crmont]

It's working perfectly. That was definitely a defrost cycle and a mini split inverter system is designed to never shut off.

A word of advice; if it's not working as you'd expect, walk away for 10 minutes. That always fixed things. Congrats on your new system!

[energy_rater_La]

now, spend the money to get a blower door test and
air seal the house. esp where new addtion connects
to older portion.
have ducts in crawl tested & mastic sealed.
it is much more affordable to heat a house with few holes
than a house with lots of holes.

I'm curious about this..you talk about ducts in crawlspace
no heat in addition...and then ducts in walls..is it that the ducts
in the walls couldn't be added to the existing system?

I really hope you are off on sq ft of original house...3 tons
for 500 sq ft or even 1000 sq ft is crazy.
it may be an option to down size this unit once
house & ducts are sealed.

once the air sealing is done...then you invest in insulation.
if you just insulate over leaks you just filter the leaks thru the
insulation. de-rates the value of the insulation greatly.

congrats on the minisplit. sounds like you made a good choice.

best of luck.

[newathvac]

It's working perfectly. That was definitely a defrost cycle and a mini split inverter system is designed to never shut off.

A word of advice; if it's not working as you'd expect, walk away for 10 minutes. That always fixed things. Congrats on your new system!

I'm glad it's working correctly. I did notice that when I had it set to 72 degrees it shut off for a couple minutes. I set it to 74 degrees and it hasn't shut off since (it has been a couple hours). What determines if it shuts off completely or not?

now, spend the money to get a blower door test and
air seal the house. esp where new addtion connects
to older portion.
have ducts in crawl tested & mastic sealed.
it is much more affordable to heat a house with few holes
than a house with lots of holes.

I'm curious about this..you talk about ducts in crawlspace
no heat in addition...and then ducts in walls..is it that the ducts
in the walls couldn't be added to the existing system?

I really hope you are off on sq ft of original house...3 tons
for 500 sq ft or even 1000 sq ft is crazy.
it may be an option to down size this unit once
house & ducts are sealed.

once the air sealing is done...then you invest in insulation.
if you just insulate over leaks you just filter the leaks thru the
insulation. de-rates the value of the insulation greatly.

congrats on the minisplit. sounds like you made a good choice.

best of luck.

I am off with the square footage because I don't remember what it is exactly. I know the whole house is around 2,000 square feet. I believe the old part of the house is 360 - 500 square feet, so the addition is probably around 1,500 square feet. The addition has the duct work in the walls. The old portion of the house has duct work under in the craw space, and we were told that duct work would need to be redone, and we got the mini-split instead.

I will look into insulating the house better.

Thank you both!

[crmont]

If the room temperature meets set point and the compressor is already running at its minimum speed then the outdoor unit will shut off. The indoor unit will continue to operate its fan. The room temperature is read at the indoor unit so it's fan never shuts off completely. If the indoor unit shut it's louver then the system may be in defrost. The compressor is capable of running at a small fraction of it's full speed and it's control will try to maintain exact set point without shutting off.

[newathvac]

If the room temperature meets set point and the compressor is already running at its minimum speed then the outdoor unit will shut off. The indoor unit will continue to operate its fan. The room temperature is read at the indoor unit so it's fan never shuts off completely. If the indoor unit shut it's louver then the system may be in defrost. The compressor is capable of running at a small fraction of it's full speed and it's control will try to maintain exact set point without shutting off.

The outdoor fan has been running nonstop. It only shut off once today when it was in defrost mode.

Also, the unit outside has been loud all day. It usually gets quiet but today it has been loud. Is it because it is cold, 32 degrees or so? I just found it odd that it has been loud since it usually isn't.

You said at the beginning of your post that the outdoor unit will shut off if it meets the desired temperature, but at the end of your post you said it will try to maintain the temperature without shutting off. I don't understand.

Thank you, I appreciate you explaining how the system works.

[crmont]

The outdoor fan has been running nonstop. It only shut off once today when it was in defrost mode.

Also, the unit outside has been loud all day. It usually gets quiet but today it has been loud. Is it because it is cold, 32 degrees or so? I just found it odd that it has been loud since it usually isn't.

You said at the beginning of your post that the outdoor unit will shut off if it meets the desired temperature, but at the end of your post you said it will try to maintain the temperature without shutting off. I don't understand.

Thank you, I appreciate you explaining how the system works.

Go to your manufacturer's website and read how they work. If you post the model number I'll link it for you.

[newathvac]

Go to your manufacturer's website and read how they work. If you post the model number I'll link it for you.

It is the Fujitsu 15RLS2. I've been reading a lot about them online but haven't found the answers to my questions. I've also looked on Fujitsu's website and read through the user manual.

It has been quiet today so I'm assuming it was noisy yesterday because of the cold.

Thank you.

[jtrammel]

Might want to have a crankcase heater installed if it didn't come with one.

[SBKold]

I think inverter compressors take care of crankcase heat with trickle heat.