I thought a new thread might be in order for this question.

The backstory is that in 2010 we contracted for a hydronic GSHP system to be installed in our 1890s Victorian house in St. Paul, MN. It was to provide heating using our current radiators, and air conditioning/back up heat using a new SpacePak ducted high-velocity unit. There are both W2W and W2A units in the basement, and the SpacePak is on the third floor.

The install has been plagued with the failure of several parts, inconsistent operation, and high heating bills.

Our installer has provided many band-aid fixes over the past 3 years while claiming that the system was basically sound. After getting some great information and advice here about what would make our system more efficient, I've become more formal and more specific in my dealings with/requests of the installing company.

They have now hired a 3rd party engineering firm. They are about to do a new evaluation of the house and the system equipment. It all sounded good, except there was no mention of setting up the system to run at its most efficient. When I asked for assurance that this would be a focus of the re-design, I received the following response:

Your system will be configured to run according to industry standards for operation, assurances or guarantees about savings are not feasible.  We can provide estimates, but know that they are just that…estimates, which can range by 10-20% or more depending on not only the factors above, but many more factors (known and unknown). 

 

Our commitment to you is to ensure that your system is properly installed, configured and controlled to meet industry standards for efficient operation.  You should be able to rely that your system will function as designed, be reliable when used as designed, and also when properly maintained following manufacturer requirements for annual maintenance. 

 

We look forward to completing our evaluation, and implementing our adjustments to your system.

So, my question is: is there one set of industry standards they will be using, or do they get to pick and choose from among different standards? I can no longer look at this objectively, and I am hoping that the message above is good news, but would like your opinions!  Thanks!

It doesn't mean much. If you have a dispute, it will almost certainly have to go to expert testimony as to what constitutes "industry standards" and it could be just about anything. You will have just as much success going in front of a judge and saying, "Your Honor, I paid a reasonable price for this and I expect it to work." He will agree with you if the system doesn't function at all, but beyond that, it's a wide open world as to what the standards are.

If your current radiators are either the original hot water radiators or ones meant to be used with a boiler, I think you are going to have a problem trying to make them work with a heat pump, aren't you?

Sounds pretty vague to me unless they list the actual standards.

"Industry standards" generally refers to installation practices i.e. deburring copper line after cutting. It would also mean following manufacturers' installation instructions which was not true of first install of SpacePak for instance. It says little about efficiency.
However if geo is set up to run first stage (and yes it will work with radiators if properly controlled) and control system is properly designed, there is no reason it shouldn't cost less to run than your old boiler.

Posted By joe.ami on 04 Sep 2013 07:40 AM
"Industry standards" generally refers to installation practices i.e. deburring copper line after cutting. It would also mean following manufacturers' installation instructions which was not true of first install of SpacePak for instance. It says little about efficiency.
However if geo is set up to run first stage (and yes it will work with radiators if properly controlled) and control system is properly designed, there is no reason it shouldn't cost less to run than your old boiler.

This is as I expected, and why I asked them to commit to using efficiency as a metric when "redesigning" the solution. They treated my request like I was asking for a guarantee.
The third party will be at my house tomorrow re-doing the heat calc and eyeballing the system. It is a mystery why their first visit to the house at the beginning of August didn't include these steps. Now we've had another month of running the AC with 3 pumps in series vs the one pump that it is speculated is needed.
I want to believe they will do the right thing, but the fact that they will not share their current thinking has me worried.

Posted By tamar on 04 Sep 2013 10:10 AM
...They treated my request like I was asking for a guarantee. ...

Many pros in this forum offer performance guarantees.  If I recall correctly, some even offer it in writing.

It is easy to guarantee performance if you are confident in what you are doing. Sometimes customers ask me if guarantee the performance of the system, the answer is "yes, of course". But I ask them pick the definition what performance is, that is when the issue usually gets buried.
And no, it is usually not a problem to make old radiators work with heatpumps, if you have the correct design and equipment.

Posted By docjenser on 04 Sep 2013 12:19 PM
It is easy to guarantee performance if you are confident in what you are doing. Sometimes customers ask me if guarantee the performance of the system, the answer is "yes, of course". But I ask them pick the definition what performance is, that is when the issue usually gets buried.
And no, it is usually not a problem to make old radiators work with heatpumps, if you have the correct design and equipment.

So, what would a smart, reasonable customer specifically ask for in terms of a performance guarantee (I want to appear both smart and reasonable)? A certain COP? A certain temp differential between water coming in and water going out?

EDIT: I know the system will not be its most efficient if W2W isn't stage one. That's a given. OR, they should remove the high temp W2W and refund that portion of the huge amount of money we paid....

Good question Tamar. Certainly your cost to heat the home should be less than before the system was installed.

Posted By joe.ami on 05 Sep 2013 10:03 AM
Good question Tamar. Certainly your cost to heat the home should be less than before the system was installed.

Agreed. We had a 40-50 year old monster of a boiler back in 2009. I can't imagine it was more that 70% efficient.
I would like to think that a GSHP system would also be more efficient than a new gas boiler, given the utility rates at the time we installed the system....I know rates are different now and nat gas prices have fallen. We were told MANY times that we'd save money; a promise that has not materialized.
I visited the Carrier website last night, and see that the hi-temp W2W should have a COP of 3.2-4.5. They use ARI/ISO 13256-1 for their standard, if that makes sense.

We were told MANY times that we'd save money; a promise that has not materialized.

OMG. You put a new system in and it costs MORE than what you were doing before? What did they tell you about the energy usage, not necessarily in terms of cost, but in terms of cleanliness and efficiency?

Posted By ICFHybrid on 05 Sep 2013 10:26 AM

We were told MANY times that we'd save money; a promise that has not materialized.

OMG. You put a new system in and it costs MORE than what you were doing before? What did they tell you about the energy usage, not necessarily in terms of cost, but in terms of cleanliness and efficiency?

They told us we'd save lots of money while being good stewards of the environment. I know there are a gazillion factors at play, but as an example, our Dec 2010 bill was $615 (first winter using geo, combined gas and electric without separate meters-which we now have). Previous all time high for us was $540. Many things have changed since then, but we still use over 4000 KwH in winter months when leading with GSHP. In Feb 2013 we heated all with gas boiler and the bill was under $200.

And no, it is usually not a problem to make old radiators work with heatpumps, if you have the correct design and equipment.

Really? How does that work when you have radiators designed for 170F water ( or higher) and want to make them work with 110F water?

In houses that old, radiators were very often oversized. This was to account for not only extremely leaky homes, but in some cases to allow for adequate heating with windows cracked to bring in fresh air. Some analysis could look at the existing heat transfer capability of the radiator surface area accounting for the lower delta T to determine how much of the heat load existing radiators can cover at 110 degree EWT.

In houses that old, radiators were very often oversized.

So, the answer is that you hope the systems were oversized in the first place? How high do you push the operating temperature from a heat pump in order to meet heat load?

ICF. Tamar has the high temp geo which can go to 130 or so. The back up boiler and HV system are 2nd and 3rd stages. May I suggest you read Tamar's other thread as all this is discussed in great detail.

To the topic......
Tamar I know you want a measuring stick (such as COP) to ratify the result, but dollars are more important (and transparent in a suit).......Would you like to tell the referee "They promised a 4 COP and I'm only getting 3.25" or "I spent $XX,XXX.XX dollars on this system to save money and my utility bills are higher".
One will make eyes glaze over while one makes them pop out of your head.

According to Carrier's website, the 50YEW High Temp meets energy star standards of 3.0+ COP and its efficiency is listed as "up to" 4.2 COP. I doubt the current control configuration gives us much over a 2.0 COP, but I don't know how to retroactively figure that out.

My goal right now is to keep this out of court or away from a referee by having a clear definition of what outcome will we consider to be a fulfillment of the original promise. I've communicated our initial goals that they should have understood when they sold us the system.

1. An efficient system that heated and cooled our house with an environmentally friendly system that would save us money because we were using less traditional-type energy
2. A reliable system that would be easy to maintain and not need a lot of maintenance/have a lot of downtime
3. A system that we understood, so that we would know when it was functioning as designed (in terms of staging, performance, etc)

Low heating/cooling bills would fulfill the first requirement. I just don't know how to measure that any new proposal is the best they can do, vs where they may be cutting corners.

Posted By tamar on 06 Sep 2013 09:28 AM
... I've communicated our initial goals that they should have understood when they sold us the system.

1. An efficient system that heated and cooled our house with an environmentally friendly system that would save us money because we were using less traditional-type energy
2. A reliable system that would be easy to maintain and not need a lot of maintenance/have a lot of downtime
3. A system that we understood, so that we would know when it was functioning as designed (in terms of staging, performance, etc)

I think your goals are excellent for what you want to accomplish, but not perhaps realistic for what you can expect of the installer / manufacturer.

I do a lot of work for companies that are interested in separating themselves from competitors for business advantages by offering performance guarantees.  The work I do is implementing the energy and performance monitoring systems to put fact to whatever the setup is.

In the course of doing this work, I've learned how hard it is for companies to offer performance guarantees, and thus why you don't see it being done much, and virtually not at all in the residential market.

For example, I'm doing some work currently for a geo heat pump installation firm focused on the residential market.  "Contract with us, and we'll guarantee you x amount of savings."  That's the objective they want to see if it's possible.

This is pretty hard, actually, because the installer has no control over the lifestyle and habits of the customer.  The performance of HVAC systems changes a lot dependent on so many out-of-the-contractor's-control things.  I.e., thermostat settings, changing to high intensity light fixtures, leavings doors/windows open, and sudden damage to the structure.

In order to offer realistic performance guarantees, the contractor has to think of all of these things, and, then put in monitoring to have an 'independent third party' data source.  Or stipulate limits, like x amount of KBTU removed from the structure as a function of CDD.  Not easy, complicated and confusing to many home owners, and thus not commonly done in the residential market.

What you can expect of the installer / manufacturer, IMO, is equipment that performs to manufacturer specifications.

To rightfully have this expectation, though, you need to be sure you allow for (and pay for) alterations to your existing situation that otherwise would prevent the new equipment from performing to manufacturer specs.  A common forced-air system example is where the customer purchases a new system but is unwilling to pay for ductwork alterations and thus the new geo system is artificially constrained from performing properly.

In your case you have geo units and thus this makes it pretty easy to measure key performance items.  You could implement a measurement system, and then verify you units' performance versus advertised specs.  This is not difficult, but, would require some expenditure on your part to implement.

Best regards,

Bill

Here is what a 3rd party is going to do, at our installer's expense (or they have called in a big favor):

Provide written recommendation for proposed corrective work if required, including.

o Heating and cooling load calculations comparison to XX-company.

o Verify that the existing heat pumps can handle the space heating and cooling.

o Verify the size of the vertical loop heat exchanger.

o Redesign the piping system and add a boiler in the design.

o Provide control sequences as required for the hydronic system

o Verify or reselect the pumps if needed.

o Verify that the ductwork is properly sized.


And I responded with this request: May I request that the program be modified to add some wording about ensuring the system is controlled in the most energy efficient manner (that saves money over a traditional heating system)?

I got the response above (opening post), which does not mention efficiency at all. That distresses me.

We paid a huge amount of money that was supposed to cover all work that was required, including all new ductwork in our hot-water-heated house. Lots of discussion about "typical payback" and even a comment that we'd be able to keep the house at 80 degrees if we wanted to and still save money on our heating bills. I really just wanted some assurance that they wouldn't cut corners at the expense of increasing efficiency.

The latest visit (yesterday) was a gentleman who has "LEED AP" credentials. One of his first comments to me after introductions was that he couldn't believe I was still being civil about the issues, given that the system was installed 3 years ago. I like him....

Tamar has the high temp geo which can go to 130 or so.

I realize that. My question had to do with how high a temperature the heat pump was being asked to deliver to a radiator system that was designed for much higher temperatures. Your answer seems to be that such a system would push the heat pump to what, maximum output?