The ‘New England Drain Back’ Solar Hot Water Appliance
Compact solar hot water system with the highest rated collectors available in the US and a 20 tank year warranty
Stainless Steel Tank – The solar hot water storage tank is the most important piece of equipment in a solar hot water system. You will have made a decision to purchase a solar hot water system based on the expected return on investment, or payback time. What happens to that return on investment if you have to replace the solar tank in 10 years? Or in 6 years? You simply cannot install a solar hot water system with a tank that does not last as long as the rest of the system.
Highest Collector Rating in the US – We use Kingspan flat panel collectors. These collectors were selected as they generate the highest possible MassCEC rebate. This rebate is based on the ‘cloudy’ day SRCC rating; and these collectors excel in these conditions.
A NESHW system is one of 20 different systems across Massachusetts upon which the Massachusetts Clean Energy Center has installed energy monitoring equipment. This system has the highest performance of all the monitored 2 panel systems. The next closest competitor had over 20% less output, and cost the homeowner $1640 more.
The ‘New England Drain Back’ Design – There are two major solar hot water system types-‘drain back’ and pressurized ‘closed loop glycol’ (CLG). Pressurized CLG solar loop systems are always ‘full’ and thus have an expansion tank and pressure relief valve. If you know many people with pressurized CLG systems, then you know that there are many potential problems including overheating in the summer and expansion tank failure. All NESHW systems use the drain back design (or it’s close cousin- ‘steam back’) which means that when the system is not running, all of the system’s fluid drains back and the solar loop and collectors are ‘empty’. So, if the storage tank temperature reaches its maximum, the pump stops and all of the fluid drains from the collectors. Also, if there is a power outage or electrical problem, the collectors are empty. These systems are thus immune to damage from overheating, freezing, and power outages. The solar loop is also unpressurized, which increases collector life.
Most drain back systems are ‘open systems’ that require that the solar loop plumbing be properly sloped or water may collect in piping’s low points and freeze. And most also require the periodic addition of water. All NESHW systems avoid these limitations by using a freeze proof, food grade glycol in a ‘closed loop’ design.
All of these factors reduce maintenance and increases NESHW’s system life. Most CLG systems are warrantied for one or two years. We provide a 20 year tank warranty and 10 or 11 year collector warrranty.
Versatility – The NESHW appliance can be configured as either a ‘preheat’ system where you keep your existing hot water heater (a ‘two tank’ design), or as a ‘stand-alone’ or single tank design that provides 100% of your hot water. In both cases, solar will provide some large fraction of your total hot water needs (the ‘solar fraction’), while the back-up heater provides the rest. In a preheat or two tank design, your existing hot water heater (gas, oil, electric, or on demand) provides the back-up hot water heat. In a single tank design, the NEDB tank’s on board electric element provides the back-up power. For a family of 4 with good solar exposure, the NEDB appliance will typically provide 60 to 80% of your annual hot water heating needs from solar alone.
Price – Most NESHW appliance installations will cost about $2,000 or less after tax credits and rebate. No-one else comes close to matching our price, quality and experience. The payback will depend largely on the type of fuel your home uses to heat hot water.
Your NESHW hot water appliance will qualify for a 30% Federal tax credit, a 15% state tax credit, and a $3-4,000 MassCEC rebate. The ‘out of pocket’ cost to you will be about $2,000 (less if you qualify for the MassCEC rebate moderate income adder). After that, your system will pay for itself many times over its 20 to 25 year life. One way to look at it is that over the next few years, you will pay for a NESHW appliance whether you buy one or not!