Originally Posted by idlewild (Post 2437086)

We recently had our ~300 sq ft. south-facing lanai enclosed with single pain / non-insulated glass on our ~1900 sq ft home. The wife wants "open living" (i.e. to keep the doors to the lanai open) and thought we could do it after we blew insultation into the lanai.

I'm concerned that not only are the new windows and door not double-paned (i.e. no insultation) but also the added space will strain our AC unit In fact, when I saw the price of a mini-split I figured we might be able to extend the existing ductwork into the lanai after insulating, but I was told from multiple contractors that this would strain the AC and is not to code.

Questions: even if we blew insultation, how much cool air would we be bleeding from the single-pain glass? With this leakage and new 300 sq feet to cool, how much of a load/strain would leaving the doors to the lanai open place on our AC unit and is that comparable to having the ducts directly into it?

My idea of "open living" is not keeping the doors open, but rather using the lanai occasionally with the doors open (i.e. air conditioning from the home) but mostly using it later at night with windows open for a breeze to naturally cool it, but I supposed we're going to have to minimally both blow insulation and get a mini-split if my wife wants to keep the doors open all the time, correct?

Originally Posted by idlewild (Post 2437086)

We recently had our ~300 sq ft. south-facing lanai enclosed with single pain / non-insulated glass on our ~1900 sq ft home. The wife wants "open living" (i.e. to keep the doors to the lanai open) and thought we could do it after we blew insultation into the lanai.

I'm concerned that not only are the new windows and door not double-paned (i.e. no insultation) but also the added space will strain our AC unit In fact, when I saw the price of a mini-split I figured we might be able to extend the existing ductwork into the lanai after insulating, but I was told from multiple contractors that this would strain the AC and is not to code.

Questions: even if we blew insultation, how much cool air would we be bleeding from the single-pain glass? With this leakage and new 300 sq feet to cool, how much of a load/strain would leaving the doors to the lanai open place on our AC unit and is that comparable to having the ducts directly into it?

My idea of "open living" is not keeping the doors open, but rather using the lanai occasionally with the doors open (i.e. air conditioning from the home) but mostly using it later at night with windows open for a breeze to naturally cool it, but I supposed we're going to have to minimally both blow insulation and get a mini-split if my wife wants to keep the doors open all the time, correct?

Originally Posted by skippy05 (Post 2437510)

It might be less expensive and less trouble to just replace the wife?

Originally Posted by talonip (Post 2437490)

We have had two houses and enclosed both. Single pane. Don’t get sucked into double pain unless you have a west facing lanai with unobstructed view. We put insulation in the first house with 280 sq ft lanai. In second home we did not with 500 sq ft. Hardly noticed a difference. We put two mini splits in second lanai. We love it. One thing that is nice the villages weather and temp from late Oct to middle of April is great. Mini splits use was minimal. We use our lanai all the time. It’s well worth the cost to enclose and pit mini splits in. Ask contractor to put in the flush ceiling mounted mini.

Originally Posted by retiredguy123 (Post 2438812)

Don't get sucked into double pane??? If you have a room that is being heated and cooled, why would you use single pane glass windows? Double pane glass has been the minimum standard for all windows in housing construction for longer than 30 years. Nobody installs single pane windows in a house that is heated and cooled.

Originally Posted by Nana2Teddy (Post 2437546)

This is our situation. We chose single pane for east facing 400sf lanai because it was $15K vs $29K, and Custom Windows told us single pane was sufficient. We had ceiling insulated and two ceiling mounted minisplits installed by Kalos, and they work great except in the dead of summer when the morning sun heats up the room quickly forcing the minisplits to work extra hard all day trying to cool it back down to 75. So, we have 100% solar blocking interior motorized shades being installed next week to block morning sun until 11-12, then will raise them for rest of the day and night. The shades will block the sun from fading everything in our lanai too. This is a private fenced-in yard, no view, so we don’t mind shades being down in morning for 2-3 months annually. We do keep our sliders to the lanai open all day.

Originally Posted by retiredguy123 (Post 2438812)

Don't get sucked into double pane??? If you have a room that is being heated and cooled, why would you use single pane glass windows? Double pane glass has been the minimum standard for all windows in housing construction for longer than 30 years. Nobody installs single pane windows in a house that is heated and cooled.

Originally Posted by C. C. Rider (Post 2439379)

I disagree. The window insulation requirement is based on temperature difference between the outside temperature and the desired inside temperature. Up north, it may be 0 degrees outside and 70 degrees inside. That's a temperature difference of 70 degrees. You definitely need double-pane windows for a 70 degree temperature difference.

Down here in Florida, the "winter" is so mild as to make thermopane windows unnecessary. As for the summer cooling, it seldom gets hotter than about 95 degrees, and that's only for a few hours per day in the hottest part of the summer. Your temperature difference then is only about 17 degrees if you keep the inside at 78 degrees.

Many people would argue that thermopane windows are unnecessary for a mere 17 degrees temperature difference. My 2,400 square foot house has single pane windows, including my enclosed lanai, and my heating and cooling bills are very modest even during the hottest part of the summer.

In short, Leesburg is not Minneapolis. :)

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Originally Posted by C. C. Rider (Post 2439379)

I disagree. The window insulation requirement is based on temperature difference between the outside temperature and the desired inside temperature. Up north, it may be 0 degrees outside and 70 degrees inside. That's a temperature difference of 70 degrees. You definitely need double-pane windows for a 70 degree temperature difference.

Down here in Florida, the "winter" is so mild as to make thermopane windows unnecessary. As for the summer cooling, it seldom gets hotter than about 95 degrees, and that's only for a few hours per day in the hottest part of the summer. Your temperature difference then is only about 17 degrees if you keep the inside at 78 degrees.

Many people would argue that thermopane windows are unnecessary for a mere 17 degrees temperature difference. My 2,400 square foot house has single pane windows, including my enclosed lanai, and my heating and cooling bills are very modest even during the hottest part of the summer.

In short, Leesburg is not Minneapolis. :)

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Originally Posted by jrref (Post 2439399)

I'm not disputing what you have said but regardless, single pane windows will increase the heat load on the system and as a result you may need to purchase a larger system or if not, it will definetly be working harder to cool. Then end result is you will be paying more running it for the service life of the system.

Originally Posted by C. C. Rider (Post 2439486)

I'm not saying that single pane windows are as energy efficient as double pane windows. I'm simply saying that the slight extra cost for heating and cooling a house with single pane windows to reasonable temperatures here in central Florida doesn't justify the significantly additional cost of the double-pane windows all over the house.

My all-electric house with my wife and I living here year-round averages using 35 KwH per day or about 1,050 KwH per month. My average monthly bill with SECO is about $150 and I have NO gas bill. I can't complain at all about those costs.

EDIT TO ADD: According to this link Florida Building Code • Requirements • Windows | FHIA Remodeling Blog, it doesn't appear that double pane windows are required in this area.

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Originally Posted by C. C. Rider (Post 2439486)

I'm not saying that single pane windows are as energy efficient as double pane windows. I'm simply saying that the slight extra cost for heating and cooling a house with single pane windows to reasonable temperatures here in central Florida doesn't justify the significantly additional cost of the double-pane windows all over the house.

My all-electric house with my wife and I living here year-round averages using 35 KwH per day or about 1,050 KwH per month. My average monthly bill with SECO is about $150 and I have NO gas bill. I can't complain at all about those costs.

EDIT TO ADD: According to this link Florida Building Code • Requirements • Windows | FHIA Remodeling Blog, it doesn't appear that double pane windows are required in this area.

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Originally Posted by C. C. Rider (Post 2439515)

None of the referenced links that I read compared the cost difference in a warm climate such as Florida. So, using my all electric home as an example, let's do some "back of the envelope" figuring.

Let's say that a house with ALL double-pane windows costs an extra $6,000 here in Florida. Now, again using my heating/cooling costs as an example, let's say that my monthly electric bill in my ALL ELECTRIC home was reduced about $30 per month if I had all double-pane windows.

OK, so $30 per month equals $360 per year. At that rate, it would take 16.7 years just to break even. I don't know about you, but if someone offered me $6,000 CASH TODAY or $30 per month for the next 16.7 years, I'm going to take the $6,000 CASH TODAY!

Further, if you studied economics and the "time value of money", you'll know that dollars "saved" at some point in the future aren't worth nearly as much as dollars saved TODAY. So, if we factored that into our "break even" point above, it would take MUCH longer to break even than 16.7 years.

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Originally Posted by C. C. Rider (Post 2439486)

I'm not saying that single pane windows are as energy efficient as double pane windows. I'm simply saying that the slight extra cost for heating and cooling a house with single pane windows to reasonable temperatures here in central Florida doesn't justify the significantly additional cost of the double-pane windows all over the house.

My all-electric house with my wife and I living here year-round averages using 35 KwH per day or about 1,050 KwH per month. My average monthly bill with SECO is about $150 and I have NO gas bill. I can't complain at all about those costs.

EDIT TO ADD: According to this link Florida Building Code • Requirements • Windows | FHIA Remodeling Blog, it doesn't appear that double pane windows are required in this area.

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Originally Posted by thelegges (Post 2439532)

Our 2,872sf house with a pool KwH daily usage in summer months is 28-31KwH. Windows are double pane house is navy blue, which does draw more heat than our yellow house

Originally Posted by JRcorvette (Post 2437566)

You definitely should insulate the ceiling and it may be required. Double pane glass does not help all that much. Better to spend the money on some sun screen shades to use when needed. I would suggest try leaving the doors open during the daytime and close when you go to bed (mostly for security). See how your energy bill changes. An extra 300sf is not that much. The cost of adding a mini split AC is between $6000 & $7500. Do the math that will cover many years of a slightly higher AC bill.

Originally Posted by C. C. Rider (Post 2439515)

None of the referenced links that I read compared the cost difference in a warm climate such as Florida. So, using my all electric home as an example, let's do some "back of the envelope" figuring.

Let's say that a house with ALL double-pane windows costs an extra $6,000 here in Florida. Now, again using my heating/cooling costs as an example, let's say that my monthly electric bill in my ALL ELECTRIC home was reduced about $30 per month if I had all double-pane windows.

OK, so $30 per month equals $360 per year. At that rate, it would take 16.7 years just to break even. I don't know about you, but if someone offered me $6,000 CASH TODAY or $30 per month for the next 16.7 years, I'm going to take the $6,000 CASH TODAY!

Further, if you studied economics and the "time value of money", you'll know that dollars "saved" at some point in the future aren't worth nearly as much as dollars saved TODAY. So, if we factored that into our "break even" point above, it would take MUCH longer to break even than 16.7 years.

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Originally Posted by C. C. Rider (Post 2439542)

Is that house "all electric" like mine? Also, are you heating the pool?

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