Ductless (multi-split) geothermal (GSHP) ?

[hult]

Historic house is three-story, 180-years-old, solid brick interior and exterior walls with installed (some badly) ducts. Low-R envelope and resulting high energy $ has driven us toward 9-ton, closed-loop geothermal solution.

And unusual heating and cooling loads and difficulty of installing ductwork through brick walls -- especially to second floor -- make at least partial ductless multi-split from GSHP attractive. (Hydronics alone don't solve cooling need.)

There are plenty of split GSHPs with conventional air handlers available, but seemingly no ductless GSHP systems. Is there a commercial solution? Or would one have to be customed engineered? Seems like some progressive company would have been onto this combination by now.

TIA ... Marc

[fsq4cw]

The preferred solution is either Liquid-to-Water or DX-to-Water Geothermal Heat Pump(s) with Hydronic fan coils. This solution will satisfy both heating & cooling - without the need to install forced air ducts! Only (relatively) small holes will have to be made to pass ~1in. pipes (plus insulation).

SR

[hult]

The preferred solution is either Liquid-to-Water or DX-to-Water Geothermal Heat Pump(s) with Hydronic fan coils. This solution will satisfy both heating & cooling - without the need to install forced air ducts! Only (relatively) small holes will have to be made to pass ~1in. pipes (plus insulation).

SR

Thanks for the prompt reply.

DX is not an option (I'm a hydrogeologist and that much refrigerant in the ground gives me the willies ...). A water well was drilled for open-loop but it failed to provide adequate volume for heat pump. [I'm also an optimist ;-) -- It will be re-purposed/salvaged for garden irrigation. ]

One of the most problematic rooms already has a Trane heat-only console. Ridding the room of that eyesore was one of the anticipated benefits of the HVAC make-over. A hydronic valence was considered when the open-loop supply was anticipated. We have not re-visited that option. Suggestions?

Also: Residential *high-efficiency* liquid-liquid GSHPs are hard to find. WaterFurnace's Synergy 3D has good efficiency (although less than Envision) but its liquid loop is heat-only (Why !!? )

... Marc

[teeball57]

They make a hydronic heat and cool coil that looks and works like a ductless split system. They need water lines, drain, and electrical connection. No outside unit required with water to water GSHP.

[hult]

Also: Residential *high-efficiency* liquid-liquid GSHPs are hard to find. WaterFurnace's Synergy 3D has good efficiency (although less than Envision) but its liquid loop is heat-only (Why !!? )

Ground-loop efficiencies for Heat Controller's Comfort-Aire new HWW Series Water-to-Water Systems don't look so good once one realizes that they have the data for ground-water and ground-loop reversed ...

http://www.heatcontroller.com/products/pdf/HC-HWW-B.pdf
http://www.heatcontroller.com/produc...W%20models.pdf

... Marc

[hult]

They make a hydronic heat and cool coil that looks and works like a ductless split system. They need water lines, drain, and electrical connection. No outside unit required with water to water GSHP.

And most of what I've seen are floor-mounted consoles that look straight out of a 1960's government office building .... Can you steer me to a low-sone, high-mounting, unit that has a hand-held remote and other features that characterize the current crop of split mini ductless?

My original question remains: Are there any modern multi/mini-split that use geothermal/GSHP technology ?

Thanks!! Marc

[hult]

And most of what I've seen are floor-mounted consoles that look straight out of a 1960's government office building .... Can you steer me to a low-sone, high-mounting, unit that has a hand-held remote and other features that characterize the current crop of split mini ductless?

Answering my own question:

http://www.multiaqua.com/

Any others?

Thanks ... Marc

[teeball57]

And most of what I've seen are floor-mounted consoles that look straight out of a 1960's government office building .... Can you steer me to a low-sone, high-mounting, unit that has a hand-held remote and other features that characterize the current crop of split mini ductless?

I'm not referring to floor mount units....See Mr. Google> Multi aqua!

[nexsen]

I have not found any water sourced mini-splits but the commercial versions of mini-splits labeled VRF or VRV (for variable refrigerant flow or volume) offer water sourced condensers. Look at the Mitsubishi City Multi as well as the Daikin VRV equipment. I'm sure competitors like Sanyo and LG probably offer them too. All I have found so far are available in 3 phase power only so none address the residential market where 3 phase power is rare.

I would definitely like to see single phase water sourced mini-splits.

[geostuff]

Hydronic fan coils--water to water unit would work.

[nexsen]

I've always felt a water to water system would be more efficient - and theoretically it "should be" - but as I look at the efficiency (EER) of most water to water units none that I have found approach the 27 to 30 EER of the current water to air GSHP units.

I posed the question as to "why" in a recent on-line seminar and the manufacturer's rep said they have to use commercially available tube in tube heat exchangers. I'm stunned by that answer. Surely it would make sense to spend more to custom fabricate larger heat exchangers considering the tremendous cost of the geothermal source!

I've actually seen air to air systems with higher EER's (close to 20) at part load than some of the water to water GSHP's! How can we justify drilling geothermal loops to install a water to water GSHP with an EER of 17 if we can have an air to air system with an equal or better EER?

And making matters "worse" the stated EER of the water to water units often does not include the water source pumping energy (never for open loop) and can't include the energy the fan coils use to ultimately distribute the cooled or heated air. All that energy is included in the EER of an air to air heat pump even though it may be lower than what we encounter in the real world application due to increased static pressures, etc.

[fsq4cw]

“I've actually seen air to air systems with higher EER's (close to 20) at part load than some of the water to water GSHP's!”

The question is at what temperatures…

“And making matters "worse" the stated EER of the water to water units often does not include the water source pumping energy (never for open loop) and can't include the energy the fan coils use to ultimately distribute the cooled or heated air.”

COP of mono block Liquid-to-Air GSHPs do include loop pumps & blowers. However,your point is well taken.

If you’d like to eliminate ground loop heat exchangers (within the GSHP, not the ground loops themselves) & pumps, look into DX GSHPs.

SR

[jchaters]

aermec make nice fan coils (even ones that look like minisplits) as well as air to water heatpumps

[GT1980]

If any viewing 2013
pls find EER over 30 for several GSHP and well GSHP, higher!
and
raw AHRI over 40 EERS in low-med (most running hours) blended "raw" data]
and NEWS:
Hydro-Temp got its (unnecessary) 3rd party rating.

(see sites for several OEM's, below)

Hydro-Zone is a tm of Hydro-Temp for the chilled water and HW off of a forced-air same-unit system that uses the rfg off the air HX coil with modulated or no blower speed--- just for Mini-like distribution to console fancoils etc... but EER's higher, and the Heat-Reclaim 100% on demand HW IS pushing COP's near 6 as in cooling mode, the loop pumps are off line. 4zn board OEM since 1995

[geoductless]

I have a similiar problem, but I only have around 1500 square feet to heat. The house was built in the 1930's and there are no heating ducts. I would like to use a geothermal heat pump to heat between one to as many as four air exchange fan-coil heating units. As yet I have not been able to find such a system on the market. Is there such a system? or Could I design my own and could anybody help me with such a design?

[geoductless]

if you can help me with this project please send me an e-mail to: < Please put your email address in your profile, they are nt allowed in post, thank you. >

[pecmsg]

Geo
Email address are not allowed in posts please put in your profile.
Also don’t hijack old threads, please start a new one.

[nexsen]

pecmsg:

If you think it is relevant perhaps you can delete my post and re-post this to this old thread (I'm not a professional member but this information may be of use to members):

I discovered LG makes a single phase water sourced up to 4.4 ton (cooling) VRF (or mini split) system: http://www.lg-vrf.com/multi-v-water-mini.aspx

But it seems to be primarily aimed at high rise apartment buildings.

I couldn't find any stated IEER, SEER, COP or EER data in any of the product literature but some charts I found would seem to imply it's about 22 EER (I think I used 70 degree water but I'm not sure I did the calculations right using the tables in the LG manual.)

While "good" it does seem somewhat low for a water sourced VRV system. Especially considering LG has announced air sourced systems as high as 36 with promises of 40 in the future.

Also I thought the stainless steel heat exchanger it has would be suitable for well water (like cupronickel) but reading the literature I see a secondary heat exchanger is recommended to isolate the loop. That's not good since a delta T will need to be maintained between the loops to get any heat transfer and of course we'd have pumping losses in two loops although one would be a closed loop. If that raised the loop to 80 degrees the EER would drop and when pumping losses are factored in the efficiency is probably still less than some air sourced VRV systems so I hope I did the calculations wrong.

If you feel this is relevant to those searching this topic please re-post under your professional identity and if not just delete my post. Thanks

[beenthere]

Please put your email address in your profile, they are not allowed in post, thank you.

[geoductless]

if you can help me with this project please send me an e-mail to: < Please put your email address in your profile, they are nt allowed in post, thank you. >

I am a new homeowner, not a professional in the business, and do not readily understand the jargon. I have aproximately 1200 to 1500 square feet that I need to heat and dehumidify or drive off the moisture; I live in the wetest region in the lower 48. I have no heating ducts, and do not want to use them. I would like to install a geothermal heating system housing the pump in my unfinished basement, and running two coolant lines up through the basement to two different locations along the same wall separating my kitchen and living room from the bathroom and two small bedrooms with connecting hallway between the bedrooms which are located at the two ends of the house. There is a location along that wall where a heating/cooling coil and fan could be installed on both sides of the wall which could heat the bedroom and kitchen, and there is a similiar spot west along that wall where the same type set of dual heating/cooling coils and fans could be located heating the second bedroom and the living room. I would like to be recomended a geothermal system which could be set up this way. I need to know the exact product and where and how to go about obtaining and getting it installed.