I've enjoyed lurking around these forums and would like to get some opinions. Here is the situation: I'm considering Geo but I'm one of those cases where the payback may not be that soon. While our two systems are 15-years old, they are 90% efficiency and natural gas. I first got really interested in Geo when I read some of the costs which seemed very reasonable especially after the 30% tax rebate. I've only talked to two people and have not yet seen a quote in range with my initial expectations. Our home is 3700 sq/ft but we would like capacity to potentially finish part of our basement (900 sq/ft) and also a currently unfinished space (250 sq/ft). Based on our location and available land, we'd be vertical sealed loop. We have two zones. One is in the basement and the other is in the attic outside of the insulated area. (why do they do that?) My understanding is that converting to one large unit would not be feasible/suggested. Would you pump the water into the attic or do split unit for the attic? How many feet of run would I need and what would be a good number/depth of wells? Anyway ballpark thoughts on what true costs will be without going Trilogy or 7 series? I really like the one installer but the price came in $10k more than I could handle. I don't have a firm quote from the other installer but I'm not expecting great value since it almost felt like he was using geo to get my attention but was more interested in selling me conventional. I have a third guy coming tomorrow. I really don't want to waste anyone's time but this is a huge ticket item and I want to get a good quality at a decent value so I might try a fourth. I'm skeptical of the standard HVAC people who seem to do geo as an add-on. Besides for the tool on this site, is there another method to find a good reputable installer? While I might not like it, I could be willing to accept that geo is just not for me at this time. B34N
Geo is much more than just a ROI. Given your ROI priority, you might be best served by enjoying the cheap gas and considering geo when you furnaces are truly on life support. Not too much info here to make comments about loop design etc or internal system design. Load numbers are truly needed. I share you skepticism of HVAC installers with geo as a side gig. Again, geo can deliver much more than a ROI, like superior comfort especially with the 7 series. But you seem to rule that out already. Geo might not be the right choice for you yet. It is like the electric car world. People who have it rarely go back to regular cars, for all kinds of reasons, although lifetime ROI might not work out yet, and their advantages might not fully outweighs their disadvantages, depending on who you ask.
We need a heat loss that includes the additional conditioned space, I would have you think about a single water to water unit feeding both zones and the additions. I am sure we could run a pair of pipes to the attic from the basement.
Just be aware that the efficiency will be significantly reduced with a water-water design. So your options are: 1) Use a large single unit (if large enough for the load) and feed both zones through zoning. You would need to feed ductwork up to the attic. In general, a 4-5 ton unit might be large enough for a 5000 sqf well insulated house in NJ. 2) Use 2 units and just get loop water to the attic. Increased price since 2 smaller units are more expensive than a single larger one, but less effort to install. 3) One water-water unit feeding 2 air handlers with either chilled or heated water. Increased install costs, significant decreased efficiency. It all depends how you get either ductwork up in the attic, or water pipes, and at what costs. You being on natural gas with your stated eye on ROI, geo might not be for you.
Why do I always have to do the math for you? water-water COP at 32F EWT and 104 ELT ( about 110F leaving load temp) COP = 3.1. 110F is usually needed for air handlers, COP does not include fan power for air handlers. water-air COP (5 ton) at 32F EWT COP is around 4.0 in both first and second stage. Under those common scenarios COP is 20-25% better with the water to air. Add to that the additional blower power for the air handlers, and the load pumping, and you get at least a 30% penalty to feed an air handler with a water-water system, compared to a dual stage water-air. More if you compare it to a variable speed W-A heat pump.
They are not real. When and where do you see 32*F EWT? Tell me where to find a manufactures engineering table that shows 32*. You have looked at all coil sizes for every air handler ever made and they all need 110*F LWT or better to heat a home. Fan power or pump power to move heat, neither is free. Prove your imaginary numbers for a five ton air to water at EWT of 32*. A link to a table would be cool, but tell me who made it and I will ask them for the table. The great all knowing guy from the east end of lake erie picks a number from 20 to 25 as the Gospel persentage of increased efficiency. Why, because he wills it to be so.
Move this discussion with Mark over to another thread https://www.geoexchange.org/forum/t...handlers-versus-packaged-water-air-unit.6795/
Thank you for the responses. I don't know where I mentioned ROI but I do think it needs to be economically feasible. There is a benefit of added comfort, no loud compressors outdoors, longer life expectancy, more stable operating costs and better for the environment. There is also the problem of having a portion of my yard destroyed, longer installation time, having a potential costly point of failure (ground loop) and the upfront costs/opportunity costs for the funds. None of the installers have suggested the single unit to run the entire house. I suspect if it were new construction that would be the preferred option. One did mention it but said that in the past they had regrets with trying to replace two units with one because getting the ductwork to the attic didn't work out as well at they wanted. I have not ruled out the 7 series or trilogy. It was only based on input from the three installers I spoke with. They seemed to lean towards once step below those levels. I appreciate that getting a ballpark cost estimate from someone on a forum is unreasonable. Maybe instead someone can help me better understand why costs could vary so dramatically from one installer to another? Is it that some need to contract out more of the job? Do they expect higher margins for "specialty" installs like geo? Do they build in bigger buffers in case there are cost overruns?
I called it ROI since you were looking for mainly an economical payback. Retrofits can be more expensive, in your case it might be difficult to run ductwork upstairs. But 2 smaller units are simply much more expensive than 1 larger one with zoning. In our operating area, prices are similar between installers, and they all deliver quality products and systems. The question is if some are too expensive, or others are too cheap? The key is to appreciate the quality long after you forgot the price. A good contractor should not have costs overrun, he should have the experience to know the costs. He should not contract out big portions of the job (except drilling), nor should a job be "special" for him.
Right now I have two quotes. One is for two 3-ton CM Tranquility and the other is for two WF. The prior stated three wells 300' each and the later didn't specify tonnage or depth but indicated that some software would be used to determine well size. The CM included desuperheater. The WF had that as an add-on. CM quote was simple and straight forward and just providing geo HVAC and a few upgrades that they said were really not necessary. WF had three options starting with basic series 3. Next was a series 7 but with desuperheater, a Rheem water heater (my water heater is only 2 years old) and redoing my 15-year old upstairs ductwork. The "super duper" quote was for everything stated before and redoing bathroom vents, changing recessed lights, air sealing, insulation (both floor and ceiling in attic space and replacing sheet rock after spray foam. I kind of got the feeling that "super duper" option was a sales tactic to get one interested in the middle option as opposed to just the "cheap" option. I have one other person coming out. This time I went to a well driller who does a lot of loops (suggested by a good friend) who referred me to the HVAC person they parter with. I've been told that Climate Master and Water Furnace are by far the best two options. Am I doing myself a disservice in not considering others? Should I have someone quote a single larger unit? If a 4-5 ton can take care of my 3700+ sq/ft house then wouldn't there be a significant savings? I'd need less of a well and only one unit. Would running ducts to the upstairs with zoning be a bad idea? Would landscaping to "fix" the area dug up for the wells be able to be included in the installation costs and eligible for the 30% rebate? If I wanted a ecobee or nest thermostat instead, would they also work with geo? I'm a bit of a tech geek doing home automation/IoT so that would certainly help with the "cool" factor. Thanks again, B34N
We used to install CM, and switched over to WF a few years ago. They are pushing the envelope a bit more with new developments, but that is just my opinion. 1) CM and WF are now owned by NIBE so down the road there will be some consolidation. Nibe also owns Enertech, with the Hydron and Geocomfort brand. The only other quality brand is Bosch. Overall, you cannot go wrong with either brand, but the designer/installer is key. A good choice is a company who does geo full time, and not where geo is a side gig for a HVAC installer. 2) It depends on the difficulty of feeding ductwork to the upper floor/attic. Usually it is a cheaper solution, but it may not. If you go with one unit, and zone the ductwork, I personally think the WF have the better (best) zoning solution (intellizone 2). 3) Usually all the costs to put in the loop and restore the side from the impact of the installation al subject to the tax credits. Consult your tax adviser for details. 4) If you are a techie, Wf is a much deeper solution with the symphony which allows you to monitor and control remotely the vast functions of the thermostat, and the heat pump itself. Especially for the installer, to the benefit of the customer. But I admit I might be a bit bias.
