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Plate vs tube
Thank you for the "first" unbiased report I have seen on plate vs tube. Most are either plate or tube sellers and so are clearly biased. This thread was good in that you have no barrow to push in either direction. I totally agree with your assesment. Each has their good and bad, and your location and weather conditions, as well as ability to purchase at resonable cost all needs to be taken into account.
Well done
There's a lot of good information contained in this thread. I work for a manufacture where we distribute both flat plates and evacuated tubes.
It all comes down to value - which system produces the most in your area for what you spend. However, there are a few general pros and cons for each technology to consider.
Evacuated tubes produce more on cloudy / overcast days than flat plates. They also produce higher internal temperatures (our manifolds generally stay around 160-170F during the day), and are easier to maintain.
The internal temperatures will not burn anyone or cause a hazard - the heat is inside the glass tubes, and the vacuum insulation makes the outside the same temperature as it is outside.
If damage occurs - such as in a storm - a tube can be replaced easily and with minimal expense, and without draining the system or messing with any piping or components. Most manufactures will pack in a few extra spare tubes with each collector - however, replacement tubes cost around $25/each.
Evacuated tubes are also modular - they come in separate pieces that are assembled on the roof. Therefore, it's generally easier to install from a labor standpoint.
The cons, are that evacuated tubes are generally about 20% more expensive than their flat plate counterparts. They also can get very hot - and generate too much heat, so a form of heat dissipation is needed, especially in the summer months. This adds about 10% extra cost in components.
In a closed loop system (or a drain back), this is the only real difference in cost versus a flat plate. Flat plates have the same general components - controls, tanks, pumps, glycol, etc - other than dissipation and the valve that controls them.
The real point to consider is it it worth the extra $300 to $500 in system costs for an evacuated tube versus a flat plate for what you receive in return?
The answer to the question is that it depends on really where you live. In warmer climates where the outside air temperature stays fairly warm (70F+), and the weather is fairly consistently sunny, the flat plates can be a better value overall, as they will perform as well as the evacuated tubes. So in areas like Florida, Texas, Arizona, etc, most contractors and homeowners tend to opt for flat plates.
In cooler and/or cloudy climates, the evacuated tubes out perform the flat plates. So if your temperature in the winter and shoulder months stays 50F or lower, or you have rainy/cloudy seasons, most contractors and homeowners tend to opt for evacuated tubes.
The other thing to keep in mind and consider is that some flat plates can be very inexpensive and cheaply made - and some evacuated tubes can be very expensively priced. I have seen a flat plate sell for $450 or so, and an evacuated tube collector sell for $3500. Therefore, at times, when people compare costs, they run across prices like these and get an idea that tubes are vastly more expensive.
My recommendation would be to shop around and ensure you get the best value for your money. Look at the SRCC certificates and see what kind of production you get for the price you pay, and make sure you get nothing less than a 10 year warranty on either technology.
Our flat plates generally sell to a contractor for around $950 or so and the evacuated tubes that we manufacture in the states generally sell for around $1250 or so - and other manufactures will generally be around the same price or so.
Hope this information helps!
It all comes down to value - which system produces the most in your area for what you spend. However, there are a few general pros and cons for each technology to consider.
Evacuated tubes produce more on cloudy / overcast days than flat plates. They also produce higher internal temperatures (our manifolds generally stay around 160-170F during the day), and are easier to maintain.
The internal temperatures will not burn anyone or cause a hazard - the heat is inside the glass tubes, and the vacuum insulation makes the outside the same temperature as it is outside.
If damage occurs - such as in a storm - a tube can be replaced easily and with minimal expense, and without draining the system or messing with any piping or components. Most manufactures will pack in a few extra spare tubes with each collector - however, replacement tubes cost around $25/each.
Evacuated tubes are also modular - they come in separate pieces that are assembled on the roof. Therefore, it's generally easier to install from a labor standpoint.
The cons, are that evacuated tubes are generally about 20% more expensive than their flat plate counterparts. They also can get very hot - and generate too much heat, so a form of heat dissipation is needed, especially in the summer months. This adds about 10% extra cost in components.
In a closed loop system (or a drain back), this is the only real difference in cost versus a flat plate. Flat plates have the same general components - controls, tanks, pumps, glycol, etc - other than dissipation and the valve that controls them.
The real point to consider is it it worth the extra $300 to $500 in system costs for an evacuated tube versus a flat plate for what you receive in return?
The answer to the question is that it depends on really where you live. In warmer climates where the outside air temperature stays fairly warm (70F+), and the weather is fairly consistently sunny, the flat plates can be a better value overall, as they will perform as well as the evacuated tubes. So in areas like Florida, Texas, Arizona, etc, most contractors and homeowners tend to opt for flat plates.
In cooler and/or cloudy climates, the evacuated tubes out perform the flat plates. So if your temperature in the winter and shoulder months stays 50F or lower, or you have rainy/cloudy seasons, most contractors and homeowners tend to opt for evacuated tubes.
The other thing to keep in mind and consider is that some flat plates can be very inexpensive and cheaply made - and some evacuated tubes can be very expensively priced. I have seen a flat plate sell for $450 or so, and an evacuated tube collector sell for $3500. Therefore, at times, when people compare costs, they run across prices like these and get an idea that tubes are vastly more expensive.
My recommendation would be to shop around and ensure you get the best value for your money. Look at the SRCC certificates and see what kind of production you get for the price you pay, and make sure you get nothing less than a 10 year warranty on either technology.
Our flat plates generally sell to a contractor for around $950 or so and the evacuated tubes that we manufacture in the states generally sell for around $1250 or so - and other manufactures will generally be around the same price or so.
Hope this information helps!
Well done
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