When I first started to consider a GSHP for my home, the first thought that came to mind was to get more informed by searching topics in the GSHP forums. Geoexchange is place to ask questions, share information, and get advice. This and other forums have truly helped me navigate through a world of information on the subject. Ranges of cost and performance values have helped put things in perspective. As a benefit to the industry, the open dialog will speed-up the optimization of an emerging technology. I read over and over again that for choosing the best proposal, make sure the contractor is qualified and has a good track record. I totally agree. Where I have a problem is in the protocol, seemingly used by the GSHP community of contractors, to withhold technical aspects of the proposals before a contract is signed. Let me explain: The proposing contractor has expended some significant labor to come up with a conceptual design and develop a proposal. He or she does not want someone to take the details of the proposal, e.g., loads, loop size, etc., and undercut the proposal. I kind of get that. Also, does the average home owner want to be bothered with the details? Would all home owners know a KW if it bit them? The best value proposal that I received and will most likely choose was developed by a highly credentialed professional, with a long string of letters after his name, including, PE, AEE, IGSHPA Accredited Installer, Master Electrician, Master Plumber, Master High Pressure Gas, Master Waterwell Certification, LEED AP, etc. The proposal identifies cost, the type/capacity of the equipment and ground loop, materials, manufacturer, commissioning, etc. Plenty of atta-boys on his web site. Pending is information including: loads, sizing program output, and the number of wells and depth as determined by GAIA GLD and Waterfurnace GeoLink. He seems like a very nice gentlemen. There seems to be a careful balance in protecting installer’s knowledge, means and methods while promoting open competition that enhances an emerging technology. Being an engineer, I am compelled to find the best application for the problem. I have to admit that I have too little experience with geothermal systems to design and install these systems, but it’s so damn interesting – I want to know as much as possible and make an educated proposal selection. I’d prefer to get advice from the forum to get an optimum solution before the contract is signed. When I sit at the table with a pen, contract, and technical information sitting in front of me, I’m not given much of a chance to check out the technical aspects of the proposal. I most likely will ask if I can take time to review the final information, but this may be outside normal protocol. Any suggestions?
Keep in mind that we see many different customers, some want all the details in the world, but also many don't really care, the want the most efficient system for the lowest price possible. Some think a geo system is a commodity like a furnace, get 10 quotes, and take the cheapest offer. Some trust your reputation, and were referred by others. Some want all the details. We provide very detailed and itemized quotes, usually 2 pages. We usually do not include load calculations, since most people don't find it very telling, but happily provide them if being ask for it. I don't care if a customer shows my quote to other contractors, including design details. The price I give the customer is my price, which I need to get to build the best system for the buck. If then someone take the design, copies it and undercuts us, and the customer goes along with that, it is really then the right customer for my competitor. I don't want him as my customer anymore, especially if he does not understand (and appreciate) that we will go the extra mile to make sure he gets the system which serves him the best in the future, with no corners being cut.
As an engineer, I'm more often hired as a contractor than an engineer. The client does get the engineering built into the product, but I'm not stamping anything unless I'm specifically hired to "engineer" a project. The line can blur a lot and often I have to clearly state that I haven't been hired as an engineer for a project - especially when another engineer on record is responsible for the mechanics. I still will make an effort to point towards what "should" be done. But mostly, the client doesn't generally care about the recipe, they just want to know if it tastes good.
In my area the details of the design are released by the hvac contractor for a price. The price is not the price of the job, only the time and effort put into the design. As the driller I have no secrets and will tell all I know on request over the phone. Eric
I shade my bids a bit owing to the risk of getting shopped. I do not want to provide free design services to another HVAC contractor who, upon receiving my bid, need not expend hours on Manuals J and D, among other things and can then undercut us. Been there, been done that way. If a client really wants all the gory details they are welcome to pay a design fee that entitles them to take our intellectual product wherever they like.
True. In some ways it makes a case for design-bid-build. Installing GSHPs is more of a niche market and thus better fits into design-build contracts. No doubt, there should be compensation for your hard work. Unfortunately, your work developing un-awarded contracts must be accounted for as overhead on awarded projects. Although I must admit, I cannot think of a better way of doing business.
"Unfortunately, your work developing un-awarded contracts must be accounted for as overhead on awarded projects. Although I must admit, I cannot think of a better way of doing business." While in principal I agree that unawarded proposals are an overhead item for every business, why should my paying customers hump the freight for non-paying "customers"? It's one thing to bid and not get the contract...that's life. It is quite another to bid, not get the contract, and then learn that our intellectual investment in the proposal was used by others to materially improve the outcome. Those ethically-challenged abusers of our proposals are identified and blackballed onto our "fecal roster". It is a short list, but we are adamant in dealing with those who operate that way.
Simple resi jobs often take very little time to Load and Model. HVAC Calc and CM Geodesigner software often require less time than the site visit that preceeds them. With that in mind I often share these and try to educate clients on the values so that they can identify those that fudge the numbers. From time to time when you get a print via email and little dialogue or interaction, it smells like mining and I offer calcs for a fee that would come off the top of an order. It should be pointed out too that markets are not all equal. Most of my clients are blue collar trying to beat propane costs and more interested in ROI than the nuts and bolts that brought them there. Credentials in contracting are a culmination of years in the biz. In the last 14 months I've picked up 3 new state licenses and a NFPA certification (as well as a variety of sundry new certs). By the end of this year I hope to have another NFPA cert and another state license (solely because I have a day job now that's willing to pay). My geo designs will remain unchanged for all the new initials. CGD is expensive and provided by an organization that is losing clout and edge, but I may get that too if the boss wants to pay for it . Generally the only time I list a good deal of my licenses is if I'm providing a friend with a real estate inspection or challenging a real estate inspector (who is generally unlicensed in MI).
Is there a relatively simple answer you would share on how you choose the min and max inlet water temperatures for the design? For example, designing for a minimum of 30F inlet temp vs. 35F would reduce the installed loop cost but increase the operating cost - and vice versa. How much does past experience play in optimizing the capacity of a new loop design?
Entering water temp is about 30F as a standard in heating, or 90F for cooling. That does not mean that 28F or 32F is wrong, but 30F has been a good compromise for reasonable upfront costs and good performance. The units are rated at 32F in heating and 78F in cooling at full capacity. Again, equally important is the design for low pressure drop to get by with the least amount of pumping power.
DJ is absolutely right in that designing for least pumping power should be a high priority. It is sadly common for the savings derived from investing in high EER / COP geo HVAC systems be lost in ill-considered pumping designs. I don't do closed loop systems, but a common rule of thumb that also seems to make reasonable sense is that the entering water temperature should stay within 20-25 degrees of your area's undisturbed deep ground temperature. Example - if you live somewhere in the middle of the country where deep ground temp is 55*F, you'd want your loops to normally deliver EWT of 35 - 75 with occasional excursions down to 30 or up to 80 during cold snaps and heat waves, respectively. It is much more important to design for minimal pumping power rather than worrying about a few degrees either way in loop performance.
