Thinking of going GSHP

[stefanc]

4 Ton Geothermal Packaged Heat Pump with Install Package for Closed Loop Horiz

I should be moving into a new house in August and am looking to ditch the 10yr old oil hot air heat and installing a GSHP. The one linked above seems to be a real good price after the 30% tax credit and $217/ton cash back from utility company.

Anyone think that it would be worth it to move to a dual stage for $2000+ more? Has anyone here had any experience with McQuay units?

The single stage will probably payback the $4000 price tag within 5yrs pretty easily.

[AC_Hacker]

Originally Posted by stefanc

Anyone think that it would be worth it to move to a dual stage for $2000+ more?

This is a DIY blog...

'Inverter technology' (continuously variable compressor speed) is now the rule in mini-split ASHP, because of it's increased efficiency. Economy of scale has forced the price down to the point that there is no premium for this very desirable feature.

The same technology is about to appear in whole house heat pumps at a very boosted price for boosted efficiency. At some point in the future, it's price will also drop.

My advice is to go dual stage, because I doubt that the same frenzy of development will happen for whole-house systems, for the simple reason that it is not common for Asian houses to have whole-house systems.

The innovations in heat pump systems are now originating in Asia, because they are spending their money on education and R&D, while we are mired in three wars.

If you can't wait for inverter technology to finally come to your home, you can educate and equip yourself and build your own system (no minor task).

Naturally, we at EcoRenovator recommend this latter approach.

Regards,

-AC_Hacker

[stefanc]

Yeah I don't think I'll be building a variable speed compressor anytime soon . I just got my mini-split and I dont think my wife would appreciate me cutting it apart yet.

Here's the 2 stage I'm considering-

4 Ton 2 Stage Geothermal Heating And Cooling Heat Pump

[AC_Hacker]

Originally Posted by stefanc

Here's the 2 stage I'm considering

Yeah, the COP looks pretty good. Looks to be somewhere around 4 for a ground loop setup, which is what you're putting in, right?

My point about the inverter technology is that ASHP technology has evolved from about COP 2.5 to COP 3.5 and inverter technology is a big part of that. Imagine what that kind of improvement would look like in a GSHP where you're starting off with COP 4!

It will be here but I think it will take a while.

-AC_Hacker

[stefanc]

Yep, closed ground loop- the 2 stage is 4.0 on high speed and 4.6 on low speed VS 3.8 for the single stage. But the 2-stage will probably run on low speed most of the time. Another nice thing about the 2 stage is that I'll be able to run a slightly oversized system and not worry about short cycling the AC in the summer. I also plan on burying an extra ground loop to keep water temps in check.

The only thing that I'm having trouble with is the fact that I might go 2-stage and then a couple yrs later a cheap variable speed will come out.

[AC_Hacker]

Originally Posted by stefanc

...then a couple yrs later a cheap variable speed will come out.

Variable speed test advertising has begun, but I don't think production units are available, yet.... not where I live.

I do know that there is a premium price planned for them.

The total GSHP market in the US is not so big (it should be, it really should be), so investment that would drive down manufacturing cost is not gonna come from the USA (we're broke, the rest of the world is not much better, except for Asia). It's all up to Asia, now.

Your money, your call...

-AC_Hacker