ASHRAE Passes Standard 188-2015, Legionellosis: Risk Management for Building Water Systems

/

Why has ASHRAE decided to address balancing in a standard that is written for the purpose of Legionella prevention? The reason has to do with domestic hot water recirculation systems – particularly large systems with multiple returns coming back to the boiler. If these return lines are not balanced it is possible that...  

Read More

Domestic Hot Water Recirculation Part 8: Proper Application of Pressure Reducing Valves

/
Pressure reducing valves (PRVs) are a necessary component in just about any domestic hot water system served by a high-pressure domestic water supply main. In this blog we’ll discuss how to apply PRVs properly so that these “necessary components” don’t become necessary evils that create water service problems and huge energy penalties for owners.
Read More

Domestic Hot Water Recirculation Part 7: Balancing Systems with Multiple Risers

/
Ever have to wait 2 or 3 minutes (or longer) for hot water to arrive at the shower in a hotel room? If you know a little about plumbing design you may assume you’ve had the misfortune of choosing a hotel without a recirculation system. But chances are the hotel does have a recirculation system, it just isn’t properly balanced.
Read More

Domestic Hot Water Recirculation Part 6: Maintaining Temperature Control In Systems with Steam Instantaneous Water Heaters

/
Applying recirculation to domestic hot water systems with steam type instantaneous water heaters requires a little extra attention. The challenge is temperature control. Under very low load conditions, instantaneous water heater supply temperatures may fluctuate rapidly – even dangerously. Here’s why: During periods of light draw, the heater flow rate may become unstable, fluctuating between a minimal/no load draw recirculation flow rate and that same flow rate plus the draw of a single fixture. That’s what happens when a single hotel guest decides to take a shower at 3AM.
Read More

Domestic Hot Water Recirculation Part 5: Recirculation WITHOUT a Return Line

/
Not every domestic hot water recirculation system requires a return line. For residential and light commercial applications, there is another way to save water and maintain hot water at the last fixture. It involves connecting a specially designed recirculation pump....
Read More