Hot Water Recirculation

Hot water recirculation systems save water by delivering instant hot water from any tap in your home. You won't waste gallons of water waiting for the hot water to arrive!

The average home over 2,000 square feet has 125 feet of 3/4 inch pipe.
125 feet of 3/4 inch Type L copper pipe holds 3.14 gallons of water.
10 draws per day wastes almost 31.4 gallons of water.
Over a year, the use equals 11,461 gallons.
25.2 million homes waste 288,817,200,000 (that's 288 TRILLION) gallons of water per year.

Many homeowners wait 60 seconds or more for hot water to reach their faucets or showers. That's 2-3 gallons right down the drain. Each year the average home wastes 12,000 gallons. That translates into hundreds of billions of wasted gallons for all U. S. homes combined. The good news - there is an easy and affordable way to stop wasting water right now. The Comfort System gives you hot water in an instant. No more waiting for hot water means no more wasted water down the drain. And that translates into savings for you. A hot water recirculation system is also a great way to add value to your home. Save thousands of gallons of water each year. Save money. Save time. And do your part to conserve a precious natural resource. The Comfort System is an affordable and effective way to stop waiting and start saving.

There are two basic methods for recirculation of potable hot water: Gravity and mechanical. Both systems require the entire supply/return be well insulated to minimize energy losses.

Gravity Flow
With gravity flow, you can use small diameter copper or plastic. Advantages include no mechanical devices to consume electricity; no hydraulic erosion corrosion caused by high flow; and the constant flow minimizes any bacterial amplification risks.

Mechanical recirculation
Mechanical recirculation systems include: 24/7/365 constant circulation with a dedicated return line; dedicated return line with an aquastat to turn the pump on and off; dedicated return line with timed pump circulation; cross-connected hot-to-cold timed circulation with an aquastat to limit the cold water line's temperature; and a similar cross-connected system that can be motion-sensor, infrared or manually activated.

A few of the constant or timed recirculation pumps are available in low wattage and low flow versions - as low as 33 watts and 0.2 GPM! Let's examine some costs.

We're being billed at $.092 per kWh, which is 1,000 watts. A 33W circulator running 24/7/365 in my home will cost me $26.60 per year to operate.

The one remaining factor to consider is the heat loss. At 140°F in a 70°F space, 1/2-in. copper tubing that's covered with 1/2-in. fiberglass will release 15 Btuh per lineal ft. In reality, we won't be at 140°F throughout the run using a low wattage pump with low flow rates. As we lose those Btu, the Delta-T is lowered, and that will lessen the Btu-per-foot heat loss. My gut feeling is that we would either match or be lower than the cost I calculated above of $138.33 for heating water. A match would give us a net savings of $110.19.

Let's change that to a timed cycle of two hours each day to coincide with hot water peak demand usage. A 33W pump used two hours each day will cost $2.22 per year. Couple that with energy lost via piping heat emissions of $14.62 annually and you'll see a net savings of $258.28 for this application in my home.

On-demand systems will typically utilize a larger wattage pump with muchhigher flow rates to quickly displace colder water for rapid on-demand hot water delivery. Corrosion-erosion can become an issue and larger return lines (if it's a dedicatedreturn system) may be required.

A minimal reduction in costs (compared to limited timed recirculation) can be realized. On-demand systems that are manually operated will continue to have a delay in hot water delivery.

Cross-connected hot-to-cold recirculation systems create the potential for warm water delivery from the cold side of the faucet. Make sure that's an acceptable condition for your customers.

The system's initial cost and fees to run an electrical outlet may seem like a deal-killer. But if you project an annual saving of $100 and the system costs $600 installed, the ROI is an attractive 16.7%, which is also a tax-free ROI. No wait for hot water, save money and conserve energy - it doesn't get much better than that.