We are getting ready to install a geothermal heat pump and have gotten two quotes from local reputable contractors. The differences in the two quotes were primarily in the recommendation for which unit to install. One contractor recommended a Series 7 and the other recommended a series 5. The price difference is about $3800. A few facts: - we are in suburban Washington, DC - we are in a five level split house approximately 3500 square feet - both units recommended are 4 ton - the unit will be located next to our family room in our basement - we have hot and cold spots in our house and may install a zoning system later but it's not an option now We want to make the best decision for the long run but don't want to waste money. Any recommendations are appreciated along with rationale.
5 series can comfortably handle 3 zones; 7 Series up to 6 zones, FWIW. Ask both contractors to estimate annual operating cost. Series 7 is a sweet setup but may not payback the $3800 via additional cost savings during its expected lifetime. Look carefully at actual vs nominal capacity...3 ton Series 7 just MIGHT better compete with 4 ton Series 5...just a thought.
7 series, hands down. They are very quiet, and provide a very comfortable heat. The best choice if you are looking at the long run. the vast majority of my customers chooses them, and they have very high expectations after a lot of hype around those units, and they all love them...
Doc- I feel like WF should be giving you a cut for every 7 series sold, because I think they are their best sales tactic. I don't mean this in dis-respect to anyone, in all seriousness, reading all of your posts for the 7 series are a big reason I ended choosing the 7 over a 5 or a different brand.
The geo manufacturers do not quite get our social networking savvy yet. Trade shows, dealer meetings, etc., but just send something to one of us and we'll pick it apart, make some recommendations, and/or give it a thumbs up. We've all contributed for years on this and other platforms. And while I'm assuming we have good relationships with our suppliers, they really don't take advantage of that in any way. On the other hand, it allows us to call crap out, so maybe they are scared. I do have one custom made residential sized header vault coming my way for a job - free. Testing out a potential product from a manufacturer I've done some commercial vault design for. I'll keep you guys posted on that.
I don't get a cut (that way I stay more objective!), although we are a WF dealer (so in a way, I pay them!), and also install Climatemaster, Hydron and Bosch when there is the right application. But the majority is WF. I was skeptical at first, given the high price point (I was not even recommending them at first), but after seeing them run in the field and getting such enthusiastic feedback from our customers made me recommending them as our first choice. By now, about 80% of our "forced air" customer are choosing the 7 series. I have been honestly and openly critical of Waterfurnace (constructive criticism) in the past, and they are one of the few manufacturers who have listened, although some things do not change overnight. I do not want to sound promotional, but for me they have gained a cutting edge over others in the last years, both technologically and qualitatively. The bottom line is, you will not be disappointed. Just make sure they do not put in a 2 pump flow center!
I am not in the know either.....The 2 pump flow center for the 7 series is a much lesser efficient solution, since it comprises of a single stage constant speed pump (26-99) as first stage, thus it is better to design the system so only 1 variable speed pump is needed.
If two pumps are unavoidable, wouldn't it be better to operate the variable as 1st stage (0 - 50%) and then start the constant pump (50%) and let the variable vary from 50 - 100% ?
I believe their (WF) rationale was that it is not recommended to pump through an inactive constant speed pump. I usually design for max flow in order to get by with 1 variable pump, even with the bigger 5 ton unit. If that does not work, I simply use the 0-10 Volt signal to control the pump and use a Wilo instead the Grundfos
