High(est) efficiency air source heat pump?

NeilBlanchard · 11-29-13, 09:28 PM

Hi,

My Mom got some information on a Fujitsu heat pump that has an HSPF rating of 12-12.5 and a SEER rating from 25-27.2, depending on the capacity. The smallest is 9,000BTU cooling and 12,000BTU heating, and the largest of three models has ~14,000BTU cooling and 18,000BTU heating. They are single zone, and the multi zone units the ratings drop to ~9 and ~20 respectively.

Wall Mounted 9 - 15,000 BTU Hi SEER - Fujitsu Ductless Mini-Splits

What is the competition on these? How close is this efficiency to ground source heat pumps?

I have a 9' x 22' screened porch on the east side of the house, and it has a tall (4'-8"-ish) crawl space with stone walls and a dirt floor. What would prevent this from being a good place to locate an outside unit of these split systems?

jeff5may · 11-30-13, 06:15 PM

The RLS series you reference is top of the food chain in Fujitsu flavor. Lots of added features and functions besides heavenly efficiency ratings.

Comparable lines are: LG Art series, Mitsubishi Mr. Slim, Gree Terra series, Daikin Quaternity series, etc. The long and short of these lines is they all perform better than each other at SOMETHING. For example, the mitsi has "hyper heat" mode, which enables the unit to keep up with heating demand at sub-zero temps at the cost of overall efficiency. The Fuji models have more overall BTU output at "normal" temps but maintain sky- high efficiency at low temps (at the cost of overall BTU output). At this level of the product line, all the units are winners.

Pinballlooking just considered, purchased, and installed (himself) 3 zones worth of exactly what you're asking about. Apprehensive of new technology and price, he got a single-zone Gree system set up first. It wasn't long before his whole family was ready for more zones. You see, the units just work too good.

Check his thread out.

AC_Hacker · 11-30-13, 08:02 PM

Quote:

Originally Posted by NeilBlanchard

What is the competition on these? How close is this efficiency to ground source heat pumps?

The GSHP will be more efficient, but the installation cost is very high. That's why I started the 'Manifesto'.

Now, if you have a goodly amount of gumption and especially if you have a friend with a backhoe, who's hankering to be a hero, then a DIY might be worth a try. BTW, rocky ground makes it more difficult.

Quote:

Originally Posted by NeilBlanchard

I have a 9' x 22' screened porch on the east side of the house, and it has a tall (4'-8"-ish) crawl space with stone walls and a dirt floor. What would prevent this from being a good place to locate an outside unit of these split systems?

From your description, I didn't detect that your crawlspace had an abundant opening to vent the torrential amount of cold air from the outdoor unit, or a way to readily get the same amount of fresh (warmer) air into your unit.

The outdoor unit processes massive amounts of air, extracts heat and exhausts massive amounts of much colder air in it's operation. It needs to be able to breathe easily or you won't get the wonderful HSPF numbers you are looking for.

Also, if you have your ASHP located near the door where you usually enter the house, say... on a really bone-chilling winter day, you will encounter a blast of much colder air every time you enter or leave the house. Likewise, in the summer time, when you want AC for the house, and you are coming in on a hot muggy day, you'll have to wade through a blast of even hotter air as you enter. (ask me how I know)

If you zero in on a unit that you think would be right for you (maybe the Mr Slim hyper heat in your area) you should download an installation manual, it will give you some info on siting, and clearances, etc.

Best,

-AC

Mikesolar · 11-30-13, 08:12 PM

When i started putting in ductless HPs i looked at all the ones that were available and talked to my buddies over in the UK that put in and service them daily. I decided that the choice was between Fujitsu and Mitsi and the price point on the Fuji was a bit better, as was the availability from my wholesaler. So far I am pretty happy with the Fuji.

I'm retrofitting a formerly scorched air house with floor heating throughout (1800ft2 + basement). Until the Viessmann boiler is in we are using a HP for heat. I installed a 4 head, 36MBTU Fuji and they keep the place at a very comfortable (too high a temp for me) 23C and it has kept up when the outdoor temp was -10C a few days ago, with no problems. I'm not sure when we will be ready for the boiler but I'm not worried.

One of my wholesales complains that LG is the one with the highest warranty claims and the UK folks think it is crappy. Daikin was considered good but is going down hill so I would stick with the Fuji or Mitsi. Next years Fujis are supposed to be considerably better than the current ones, or so I am told.

NiHaoMike · 11-30-13, 08:22 PM

In a hot, dry climate, an evaporative hybrid A/C would offer similar efficiency to geothermal at a much lower cost.

Mikesolar · 11-30-13, 08:30 PM

Quote:

Originally Posted by NiHaoMike

In a hot, dry climate, an evaporative hybrid A/C would offer similar efficiency to geothermal at a much lower cost.

Mike.....who is Allie Moore?

NiHaoMike · 11-30-13, 08:45 PM

Just a friend of mine, who is an environmentalist. She and I are in an informal "green war", trying to one up each other when it comes to going green. So far, she hasn't been able to one up my Prius (she couldn't afford an EV) and I highly doubt she'll be able to one up my home made air conditioner/water heater. "If you can't beat em, join em" would be a great outcome, but that's probably wishful thinking...

NeilBlanchard · 11-30-13, 09:37 PM

Thanks for all the information, folks. I'll look at the Mitsubishi models, too. My brother had heard good things about those.

I called a friend who has a Hallowell Acadia 2-stage system and while he was initially very happy with it, it has now crapped out, and since that company is out of business, and the compressor subcontractor won't help him; he's got a $12K dead white elephant. He works at a company that has a number of heat pumps, and they require roughly a $300 annual maintenance, and seem to really get stressed below 30F. This means the compressors take a lot of wear and tear, and you end up relying on resistance heat or your old furnace when the temps get low.

I'm wondering about solar water heaters with a large storage tank for a heat source for heat pumps?

Also, what is the ballpark installed cost of a single zone mini split system, like the larger Fujitsu units?

My porch crawlspace is not open air. I was thinking that the thermal mass of the bare ground and the thick stone (field stone and mortar) foundation would be a "ground source" for heat, but may be limited by the speed that heat can be pulled into the air under the porch.

I'll check the build threads you linked to as soon as I can.

AC_Hacker · 12-01-13, 01:53 AM

Quote:

Originally Posted by NiHaoMike

In a hot, dry climate, an evaporative hybrid A/C would offer similar efficiency to geothermal at a much lower cost.

Is this a guess?

-AC

Mikesolar · 12-01-13, 05:20 AM

Neil,
A couple of years ago Hallowell tried to get me to be a dealer here in Toronto and I was not interested. Aside from the high price I had already heard about the reliability issues and the fact that they made changes to the compressors that was not supported by Bristol, hence I believe, warranty issues were a big burden for them.

As far as the problems a HP has below freezing, look at my previous posts. Separate out the North American, old technology units (Carrier, York,etc) from the Japanese inverter units. The differences are enormous. And as for reliability, my mentor has one Westinghouse (real Westinghouse not where they sell their name to joe blow as they now do with solar panels) put in, in the 70 that just last year needed a comp change. It runs all winter and only uses some back up electric below about -12-14C. But then, they also had a system no one uses now.

If you are going to buy one, remember that there is usually no warranty if bought through the interweb.

11-29-13, 09:28 PM	#1
NeilBlanchard Journeyman EcoRenovator Join Date: Dec 2009 Location: Maynard, MA Eaarth Posts: 383 Thanks: 78 Thanked 39 Times in 32 Posts	High(est) efficiency air source heat pump? Hi, My Mom got some information on a Fujitsu heat pump that has an HSPF rating of 12-12.5 and a SEER rating from 25-27.2, depending on the capacity. The smallest is 9,000BTU cooling and 12,000BTU heating, and the largest of three models has ~14,000BTU cooling and 18,000BTU heating. They are single zone, and the multi zone units the ratings drop to ~9 and ~20 respectively. Wall Mounted 9 - 15,000 BTU Hi SEER - Fujitsu Ductless Mini-Splits What is the competition on these? How close is this efficiency to ground source heat pumps? I have a 9' x 22' screened porch on the east side of the house, and it has a tall (4'-8"-ish) crawl space with stone walls and a dirt floor. What would prevent this from being a good place to locate an outside unit of these split systems? Last edited by NeilBlanchard; 11-30-13 at 06:54 AM.. Reason: added question

11-30-13, 08:12 PM	#4
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	When i started putting in ductless HPs i looked at all the ones that were available and talked to my buddies over in the UK that put in and service them daily. I decided that the choice was between Fujitsu and Mitsi and the price point on the Fuji was a bit better, as was the availability from my wholesaler. So far I am pretty happy with the Fuji. I'm retrofitting a formerly scorched air house with floor heating throughout (1800ft2 + basement). Until the Viessmann boiler is in we are using a HP for heat. I installed a 4 head, 36MBTU Fuji and they keep the place at a very comfortable (too high a temp for me) 23C and it has kept up when the outdoor temp was -10C a few days ago, with no problems. I'm not sure when we will be ready for the boiler but I'm not worried. One of my wholesales complains that LG is the one with the highest warranty claims and the UK folks think it is crappy. Daikin was considered good but is going down hill so I would stick with the Fuji or Mitsi. Next years Fujis are supposed to be considerably better than the current ones, or so I am told. Last edited by Mikesolar; 11-30-13 at 08:16 PM..

11-30-13, 08:22 PM	#5
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	In a hot, dry climate, an evaporative hybrid A/C would offer similar efficiency to geothermal at a much lower cost. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

11-30-13, 08:45 PM	#7
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Just a friend of mine, who is an environmentalist. She and I are in an informal "green war", trying to one up each other when it comes to going green. So far, she hasn't been able to one up my Prius (she couldn't afford an EV) and I highly doubt she'll be able to one up my home made air conditioner/water heater. "If you can't beat em, join em" would be a great outcome, but that's probably wishful thinking... __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

11-30-13, 06:15 PM	#2
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	The RLS series you reference is top of the food chain in Fujitsu flavor. Lots of added features and functions besides heavenly efficiency ratings. Comparable lines are: LG Art series, Mitsubishi Mr. Slim, Gree Terra series, Daikin Quaternity series, etc. The long and short of these lines is they all perform better than each other at SOMETHING. For example, the mitsi has "hyper heat" mode, which enables the unit to keep up with heating demand at sub-zero temps at the cost of overall efficiency. The Fuji models have more overall BTU output at "normal" temps but maintain sky- high efficiency at low temps (at the cost of overall BTU output). At this level of the product line, all the units are winners. Pinballlooking just considered, purchased, and installed (himself) 3 zones worth of exactly what you're asking about. Apprehensive of new technology and price, he got a single-zone Gree system set up first. It wasn't long before his whole family was ready for more zones. You see, the units just work too good. Check his thread out.

11-30-13, 09:37 PM	#8
NeilBlanchard Journeyman EcoRenovator Join Date: Dec 2009 Location: Maynard, MA Eaarth Posts: 383 Thanks: 78 Thanked 39 Times in 32 Posts	Thanks for all the information, folks. I'll look at the Mitsubishi models, too. My brother had heard good things about those. I called a friend who has a Hallowell Acadia 2-stage system and while he was initially very happy with it, it has now crapped out, and since that company is out of business, and the compressor subcontractor won't help him; he's got a $12K dead white elephant. He works at a company that has a number of heat pumps, and they require roughly a $300 annual maintenance, and seem to really get stressed below 30F. This means the compressors take a lot of wear and tear, and you end up relying on resistance heat or your old furnace when the temps get low. I'm wondering about solar water heaters with a large storage tank for a heat source for heat pumps? Also, what is the ballpark installed cost of a single zone mini split system, like the larger Fujitsu units? My porch crawlspace is not open air. I was thinking that the thermal mass of the bare ground and the thick stone (field stone and mortar) foundation would be a "ground source" for heat, but may be limited by the speed that heat can be pulled into the air under the porch. I'll check the build threads you linked to as soon as I can.

12-01-13, 05:20 AM	#10
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	Neil, A couple of years ago Hallowell tried to get me to be a dealer here in Toronto and I was not interested. Aside from the high price I had already heard about the reliability issues and the fact that they made changes to the compressors that was not supported by Bristol, hence I believe, warranty issues were a big burden for them. As far as the problems a HP has below freezing, look at my previous posts. Separate out the North American, old technology units (Carrier, York,etc) from the Japanese inverter units. The differences are enormous. And as for reliability, my mentor has one Westinghouse (real Westinghouse not where they sell their name to joe blow as they now do with solar panels) put in, in the 70 that just last year needed a comp change. It runs all winter and only uses some back up electric below about -12-14C. But then, they also had a system no one uses now. If you are going to buy one, remember that there is usually no warranty if bought through the interweb.