WMC Case Study

Installation Overview: Multi-storey office building in Ontario, Canada
Contractor: Triple Tech Heating, Air Conditioning and Refrigeration Inc.



  1. Four Weil-McLain Evergreen Pro 399 boilers delivering:
    1. Reduced input of 1,596 MBH and matched output of 1,532 MBH
    2. 96.5% AFUE
    3. Turndown 10 to 1 (for each boiler)
  2. Weil-McLain Aqua Plus Series 2 indirect tank to generate domestic hot water (DHW)


Contractor Snapshot:

“The previous boiler, at two million BTUs, could only be serviced by a G1 tech, which are not readily available,” says Darrell Gillespie, Owner & President, Triple Tech. “The Evergreen Pro 399 can be serviced by a G2 tech. Also, with only one boiler, if the boiler went down the building would be without heat. With four Evergreens boilers, if one needs to be serviced you still have three more boilers running. That’s redundancy and back-up.”

Gillespie says the ability to install smaller, fully modulating condensing boilers like the Evergreen Pro is key to energy savings and improved comfort level. That’s because modulating means less on/off cycling and consistent building temperature: “They perform according to the building heat loss in combination with outdoor temperatures.”

One of the many features my installers like is that all Evergreen Pro boiler sizes can be either floor mounted, or wall mounted. Most competitive boilers in the Evergreen Pro size range are wall mount design which can cause installation challenges. Since the Evergreen Pro boiler can be floor mounted, I can send one technician with a two-wheel dolly to get the boiler into the mechanical room and start installing the boiler without having to send a second or third tech. to mount the boiler on the wall avoiding possible injuries and saving manpower and labour costs.

The Evergreen boiler features the Unity Control with built-in lead-lag rotate sequencer can be used to control up to eight boilers in a multi-boiler system. The Unity control allows the Min. and Max. firing rate to be adjusted for all priorities if needed which allows us to customize the boiler for each installation. For this installation, the DHW max. firing rate was reduced to match the max. input of the Aqua Plus 55 tank at 190,000 BTU/h.

Combining the boilers and tanks like we did here, optimized the efficiency," says Gillespie. With a standard water tank, you're looking at 68% efficiency. With the Evergreen and Aqua Plus a boiler heating hot water tank in highly-insulated tank you're getting top efficiency in one package."

Gilliespie, whose team is experienced in the installation of Weil-McLain products and the Evergreen boiler in particular, encountered no unique installation requirements this time around (this is second nature for us").

While Team Triple Tech did not require any direct support for this particular project, we know when we do need support from the Weil-McLain Canada office they will be there for us, either over the phone or on-site, which many manufacturers do not offer or the response time could be days. The lack of support from other manufacturers adds cost and frustration to our projects when questions or issues arise.

I'm a Weil-McLain fan through and through have been for years and I don't sell what I don't believe in. It's a little bit of everything combined that makes us choose Weil-McLain, but their customer support in particular is really second-to-none. It's support, product, reliability. Not to mention that the 399 itself looks nice in my showroom."