wrobert4

I know that this is a hard pill for most to swallow, but we are having better success with our customers when we explain the math regarding lost efficiency miss matching different SEER equipment.

A crude example; A service call condemns the condenser of an 8 year old 10 SEER heat pump matched system. The owner only wants to replace the condenser with 13 SEER or better. Sure you can make it work in cool if you change orifices, adjust charges, etc... You might do well to achieve 10.5 SEER in cool, but understand that it will not work in heat. Another service call and surly a dissatisfied customer is now in the making.

You will do a better service to your customer and your service reputation by convincing them that there better off changing the entire system now, and let them know up front that you will most likely have to come back to service the miss matched system in the winter.

Anyone care to chime in on your experiences?

westernhvac

You will miss a lot of sales this way, but you will sleep better at night. Make sure that you have done everything you possibly can to explain this to everyone that you quote equipment to. Man, I feel better just reading this post....

flashheatingand

Why would the system not work? Are you certain that the refrigerant would not condense into a liquid? Don't get me wrong, ideally, one should get a matching coil, but ones financial situation dictates the course to take. To replace the a/h, one is looking at a minimum of $1,000.00. The h/o is likely to be angry at the fact that they are already replacing a heat pump (one really should do some sleuthing as to why the h/p went out in less than ten years), and, with todays economic situation, (job insecurity), they are already stressed out.

The way I see it, do what you think is best for the customer. If you seriously believe it is in the customers best interest to replace the a/h, so be it. I can respect that. But, if the home owner is really stressed out, tell him/her the options, give them your opinion, and let them make the decision. It's their money. The key is to give them good information

thom

People hear what they want to hear then will hold the teller responsible for what they heard.

Tell the HO that the system should work but might need additional servicing, and by a few months later the HO clearly remembers you told him the system would work fine. A year after that, the HO remembers you as the a-hole that lied to him so you could get more service work.

Forget the HO's best interest. The HO's best interest is for you to pay him for the privilege of replacing his system then washing his car. You're in business for your own best interest. That includes doing a quality job for a fair price so you get more work. It does not include screwing yourself in the long-run in order to save the HO a buck in the short run.

flashheatingand

You have been in the contracting business for a long time and seem like a pretty sharp guy. I think somewhere there is a middle ground. You certainly can't stay in business by screwing yourself over, but you will turn off many a customer by being overprotective of your own interests. One should put their recommendations in writing. If you don't think something will work right, don't do it, or if you do the work, make sure the homeowner is aware of your concerns (in writing). Surely you have had scenarios in which the home owner needed to cut corners. Would you tell him "no way"? Or would you try to find feasable alternative.Granted, Mr. Wrobert was giving a crude example.

As for the technical aspect, in most situations, one could get away with mismatched equipment 10 S.E.E.R. evaporator with 13 S.E.E.R. condensing unit. It certainly is less than ideal, but we live in a less than ideal world. That is something I know we both can agree to

R.U. Cool

In Florida the Building Department will NOT issue a mechanical permit to change out 1/2 of the system. It's easy to tell the customer they are required by law to upgrade to a matched high efficiency "complete" system. The only problem is, because the homeowner is probably getting multiple price quotes, one of the bids will be for the cheaper "partial" change-out without the permit! The homeowner is the one in the driver's seat. Ultimately they decide how much they are willing to spend.

MechAcc

I have some pdf files that I got from a Bristol compressor rep on tests that Bristol did on mismatched systems. Really an eye opener. On the loss of btu capacity on mismatching. Plus on heat pump systems head pressure tripped in heating mode. Wish there was some way they could be posted here.

Plus many manufacturers are requiring model and serial number of indoor coil on compressor changeouts on warranty jobs.

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MechAcc

Just remembered that I had posted them here.
Bristol Compressor Mismatch

Carrier Why You Need a Matching Indoor Coil

Hope you can access them.

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Teetorbilt

When I had my A/C unit replaced my friend (many years in A/C) said to go with the higher SEER in the handler. Another friend of many years who sold me the system thought that I was over-doing it and should be balanced but did what I told him to do.

I'm really not seeing any difference in kw/hr's and that's replacing a 1980 unit.

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thom

Ok, either you guys are nuts or your building department and lawyers work completely differently than ours.

Our building department and inspectors insist that we observe code and install everything consistent with manufacturers recommendations. Every lawyer I've heard of would insist on the same. I know of no manufacturer which recommends mismatched systems. In my jurisdiction, a customer cannot sign a legal agreement that allows me to ignore these rules.

So you're suggesting it makes sense to buy the system for the owner. In my jurisdiction that is exactly what you would be doing. Maybe you guys think your businesses are really social welfare agencies, mine isn't.

nhmaster3015

After assurances from manufacturers, early on I made the mistake of mis-matching condensors with disasterous results. I flat out refuse to ever mis-match equipment again.

thom

I learned this lesson the hard way. 20 years ago, We removed a water damaged parquet floor (1800 sf or so) and underlayment (a washing machine hose broke while the owners were out of the country and ran for days). Our contract called for a same-as replacement. We did the tear out, installed new underlayment, then the owner stopped the project.

The owners decided they wanted tile, not wood. I explained that the underlayment installed was inadequate and inappropriate for tile. Of course they didn't hear a word I said, they were both college professors who considered themselves the "gods of knowledge and intelligence". They insisted we tile over the installed underlayment, I refused. They said they would not pay if I did not honor their wishes (the payment was in-full at completion and included additional moneys for drying out the crawl space and repairing other damage). Finally, I relented.

We were doing the work in January. Every day I would arrive at the house to find the heat had been turned way down. Every day I explained to the HO's that the floor needed to stay warm for at least a month after the job was completed. Of course the professors knew better.

Two years later, the grout was cracking and crumbling. It appeared the tile had frozen before being fully cured. They sued me for having installed tile over an improper underlayment. Of course they claimed I was the expert and should have refused.

It cost me every penny they paid for the job plus.

So, F**K violating the rules to help out a homeowner.

flashheatingand

What happened?, or, what went wrong? I installed a 13 S.E.E.R. a/c with out changing the indoor coil once (probably a 10 S.E.E.R.) and didn't hear of any problems from the end user. This was a situation in which the house was being sold and the buyer insisted on a new outdoor unit (long story). The sellers would only replace the outdoor unit.

Having said that, I may have dodged a bullet there. In the future, I think the thing to do is give two options, replace with matching gear, or fix the condensing unit (change out the compressor or whatever is the faulty component).

I would wonder...why did the appliance fail so soon. I expect heating/cooling appliances to last at least 15 years. Perhaps, the appliance was oversized and, as a result, the system was short cycling.

I still think one can get away with a mismatch, but, cover your back because it could bite you in the butt. This is a good topic.

flashheatingand

I don't blame you for being bitter. Sorry for your situation. I can't stand lying clients, but they are a minority. I am going through a situation in which I did as the home owner wanted, and he still has not paid me a dime. The details are probably not that interesting to most people, but what I failed to do was to insist on the h/o sign off on what he wanted. We had what I thought were verbal agreements. Conflict management is not my forte, but what I did learn from this is to make sure details are in writing. If the h/o wants X, have it documented. E-mails are good forms of documentation since they are dated from a neutral source.

You can't let bad customers make you sour. Just try to avoid them (it's not that easy). Most of the time, if you take care of the customer, and it will payback in the long run. It's not like I am zig ziggler or someone like that, it's just that nobody likes a sourpuss.

flashheatingand

Thats a crazy law. This isn't a black & white issue. Granted, one should get matching gear. But, it isn't the governments place to tell the h/o what they can and cannot buy. I remember reading one inspectors take (paraphrasing). (S)He said...there are field conditions in which things cannot be done by the code. The deciding factor is, will it work & is it safe.

As you said, it isn't a good idea, but, if that is what the homeowner wants, it's not our place to tell him "no!" nor is it the govenments.

thom

We still must abide the code. Sure, we can violate it IF we have an engineers signature but then it's no longer a violation.

If a manufacturer approves connecting differing units, they are in fact approved, and not mismatched. If the manufacturer does not approve it, in writing, they are by default disapproved. Code allows only approved installations.

Good luck finding a judge/jury who will side with a contractor who violated code. It doesn't matter that the HO signed off on the violation. As professionals we are obligated to follow the law/code.

flashheatingand

Around here, it's the local inspectors call to approve it or not. Not an engineer or manufacturer. There could be a conflict of interest with a manufacturer. Sure, the manufacturer would have the a right to refuse a warranty claim, but they don't have a right to give the approval or not. In general, it's the inspectors call as to weather or not it is kosher. Around here it isn't illegal to mismatch, it is just not preferable from a performance standpoint.

In this situation, ones safety isn't being compromised. So, I don't understand why there would be any legal issues. Personally, I think a law that requires one to replace both coils is unjust. As a professional, it's our obligation to inform the homeowner of the consequences and let them decide. I can accept the issue of not getting a permit/approval as being un-professional, but, if the home-owner wants to save money up-front, it should be their call. Just my opinion.

flashheatingand

I did a google on the article you mentioned. I did not realize how much of a drop in efficiency one would get with a straight-up changeout wow!! However, it did mention that txv could minimize that problem.

How do you find this stuff? Pretty informative and interesting from an hvac point of view.

I don't blame the manufacturers for wanting the indoor coil info.

Verbal

With thb big 13 seer switch over, we did a lot of mismatching for customers...
13 seer condenser, 10 seer coil. when we sell a furnace to a customer, with the intention of adding ac we sell them a boxed coil at a discount and install it all at once. That is in the intention of having a condenser install within 6 months. Some customers take thier time. so yes we have some A/C's mismatched, we dont do it for heatpumps, And we tell the customers that their will be a loss of seer, and a TXV is used. I dont do the actual installs, so i dont know if anything else special is done. I do run service calls, and havent had any issues so far that can be nailed down to the mismatching, But the customer knows up front hes not getting a full 13 seer.

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