Equipment right sizing versus customer demands, need your input.

[Barrettservices]

Have a client with a large new home (3560) being built that I bid 6 months ago and listening to the customer requests I sized the systems at 84kbtu total like every other company and got the job. It is now time to do the install and I have since learned the value of right sizing equipment and not using the ol' 500sqft method anymore.

The issue is that I have now taken a closer look at this home and title 24 (prepared by an independent company) calls for a minimum of 36kbtu. I now want to revise the system down for efficiency and longevity issues to 72kbtu which will only change the condensers down a half ton each, no change on the furnace coil to stick with the same seer/eer ratings and maintain proper airflow. I have of course explained in great detail the benefits of doing this and the customer does not like the fact of having a rightsized system versus one that will cool down faster when the want. I have never had this be an issue for me because my customers go with my recommendations. They have a family member who has built homes in the past influencing their decisions to stick with the bigger system because in his opinion that is better. I have spent some time trying persuade both of them to leave the practices of the past and accept something new that is better for them.

Rather than getting in a pissing match with this family member which may cost me the job, the advice I am looking for is that if they do not go with my revised recommendations do you make your customers sign anything that they are aware that the systems are over-sized and may cause humidity, efficiency and longevity issues?

Thanks.

[George2]

I would write a letter nicely explaining the major problem that could arise from oversizing A/C. I would only list one main concern of yours. I would not try to use the letter as a way to persuade them. That might tick them off.

Explain that you don't want there to be any misunderstandings and ask them to sign off on it. Good luck.

[54regcab]

Explain to them by oversizing they won't see the SEER that they are paying for when it comes to thier power bills. Correct sizing is essential to obtian rated SEER in real world conditions. Explain it from a "how long does an AC run before it gets cold" angle.

[beenthere]

What kind of humidity does your area have, high low?

[Drazen]

to some point i could understand your customer.

did legislation change in time between bidding and current time? if it did not, i see no purpose for asking customer to sign anything if you yourself offered him that the same thing which you now declare as inefficient.

if legislation changed, that can be your argument to make changes, if not, you simply picked wrong time to demonstrate your new awareness.

what calculation are you using now, manual j?

[teddy bear]

Have a client with a large new home (3560) being built that I bid 6 months ago and listening to the customer requests I sized the systems at 84kbtu total like every other company and got the job. It is now time to do the install and I have since learned the value of right sizing equipment and not using the ol' 500sqft method anymore.

The issue is that I have now taken a closer look at this home and title 24 (prepared by an independent company) calls for a minimum of 36kbtu. I now want to revise the system down for efficiency and longevity issues to 72kbtu which will only change the condensers down a half ton each, no change on the furnace coil to stick with the same seer/eer ratings and maintain proper airflow. I have of course explained in great detail the benefits of doing this and the customer does not like the fact of having a rightsized system versus one that will cool down faster when the want. I have never had this be an issue for me because my customers go with my recommendations. They have a family member who has built homes in the past influencing their decisions to stick with the bigger system because in his opinion that is better. I have spent some time trying persuade both of them to leave the practices of the past and accept something new that is better for them.

Rather than getting in a pissing match with this family member which may cost me the job, the advice I am looking for is that if they do not go with my revised recommendations do you make your customers sign anything that they are aware that the systems are over-sized and may cause humidity, efficiency and longevity issues?

Thanks.

Just curuois, are providing any fresh air ventilation?
Regards TB

[Barrettservices]

What kind of humidity does your area have, high low?

Northern Cali, very low humidity. I have seen systems over-sized by more than a ton and not ever had humidity or smell issues.

[Barrettservices]

to some point i could understand your customer.

did legislation change in time between bidding and current time? if it did not, i see no purpose for asking customer to sign anything if you yourself offered him that the same thing which you now declare as inefficient.

if legislation changed, that can be your argument to make changes, if not, you simply picked wrong time to demonstrate your new awareness.

what calculation are you using now, manual j?

All of us submitted our bids before the homeowner provided the title 24 (manual J) Docs so we were all shooting in the dark.

[Barrettservices]

Just curuois, are providing any fresh air ventilation?
Regards TB

No, not required in our area and all the homes that did have HRV’s installed are either removed or turned off. We have a new law that requires whole house fans in all new homes so that takes care of the fresh ventilation I guess.

[beenthere]

Northern Cali, very low humidity. I have seen systems over-sized by more than a ton and not ever had humidity or smell issues.

Then by ove sizing he loses some efficiency, its his money to burn, no health harm,.

[teddy bear]

Northern Cali, very low humidity. I have seen systems over-sized by more than a ton and not ever had humidity or smell issues.

My question is: do you provide fresh air ventilation? This has nothing to do with humidity control. It has to do with purging indoor pollutants and renewing oxygen. Maybe you have answered the question.
Regards TB

[Drazen]

All of us submitted our bids before the homeowner provided the title 24 (manual J) Docs so we were all shooting in the dark.

well, than you have good argument, but if client insists on larger size, it may be sufficient that you have an ordinary e-mail sent to client where you described what you wanted.

[Barrettservices]

My question is: do you provide fresh air ventilation? This has nothing to do with humidity control. It has to do with purging indoor pollutants and renewing oxygen. Maybe you have answered the question.
Regards TB

Answered above but here it is again.

No, not required in our area and all the homes that did have HRV’s installed are either removed or turned off. We have a new law that requires whole house fans in all new homes so that takes care of the fresh ventilation I guess. Commercial requires 15% fresh air though

[rucomfy101]

Just a thought, have you considered two-stage equipment?

[Barrettservices]

Just a thought, have you considered two-stage equipment?

I have and don't usually use it unless i am zoning. In our area we either have nice days in the70-80's or it is 95 -110 outside it seems and the equipment rarely runs on low thus making the additional investment more than 20 years on repayment. I would say 99% of all equipment installed is single stage for this reason around here.

Besides the equipment, whether two stage or not should still not be oversized.

[bearfromobx]

97 deg dry bulb and 69 deg wet bulb 1% design temps for cooling... No wonder you don't need dehumidification!!! 23% RH explains why most of your systems don't run until it gets rediculously hot outside. Around my neck of the woods, 23% don't happen until the dead of winter

[eric1589]

If you get the job, have them sign something that says you advised them, up front, of a better way to go and they refused, based on non-professional hear say. You don't want to end up owing them money or free service based upon them refusing your professional recomendation.

Home efficiency and indoor air quality is becoming a bigger market. You don't want some home inspector or energy auditor to come along 3 month or 3 years down the line and throw you under the bus for the home owners ignorant decisions. Cover your butt, on paper.

[Barrettservices]

97 deg dry bulb and 69 deg wet bulb 1% design temps for cooling... No wonder you don't need dehumidification!!! 23% RH explains why most of your systems don't run until it gets rediculously hot outside. Around my neck of the woods, 23% don't happen until the dead of winter

Where did you get all the information from? Is there some site that tells you that info for different areas? Our low humidity is nice most of the time but it makes you skin dry all winter because of it.

[MattK]

I think most homeowners have felt the effects of an oversized system without knowing it. Find symptoms related to oversized systems and ask the homeowner if he has ever experienced them. Even if he has only experienced a couple, let him know that there are all sorts of comfort issues as well as equipment issues that go hand in hand with over sizing systems. Bigger is not better. Most homeowners, and a lot of contractors make this mistake because the existing equipment just isn't cutting it so they assume it's too small.
Stuffing five tons of AC into a conditioned space that doesn't need it is going to cause him all sorts of headaches. If you install this guys systems you better wash your hands of that customer real quick because guess who's going to be doing all the warranty work when it breaks in a couple years? We all want the revenue from a good sale but not the cost of a poor install. Do them and your company a favor and refuse the work if he doesn't listen to you. You are the "expert" after all.

[54regcab]

The big advantages customers will get from correctly sized equiptment is quiet operation and even tempatures. Customers that have never had never had these are used to furnaces coming on blowing them out, then shutting off until they freeze. They don't know what it's like not to have to fiddle with the thermostat constantly to compensate from tempature overshoots. If the system is done right the customer should never know when thier system cycles unless they are watching/listening for it.