Commercial

If there’s one thing thirty years of solar, plumbing and mechanical experience teaches you…it’s that no two installations are the same. At Solar Heat Exchange Manufacturing, we put our experience to work by designing, testing and constantly improving solar thermal systems, large and small. Our design and engineering staff has the tools and experience to design, estimate and provide working drawings for every solar thermal application.

If your interest is in commercial solar thermal, we invite you to examine this page and links in detail. From design philosphy to components and configurations, you'll find our approach to commercial solar thermal is unique.

Commercial installations represent a unique challenge, one we especially enjoy. Our estimation department works closely with engineers and technicians to design, specify, and install solar and solar hybrid systems. Our sister company, Mid-American Water and Plumbing, has installed major solar thermal systems all over the US, in some of the most demanding situations imaginable.

COMMERCIAL DESIGN PHILOSOPHY DIFFERS FROM RESIDENTIAL

Below are two bar graphs depicting the design philosophy of a residential and a commercial solar thermal system. Two major design philosophy differences are 1) btu oversupply tolerance, and 2) storage.

The first of the two bar graphs depicts a typical 2 collector residential application. Oversupply in the summer is unavoidable given two 4' * 8' collectors (shown as dark blue bars taller than light blue bars). 80 gallons of overnight storage is provided. This is a typical residential supply and demand profile. The residential solar fraction goal is approximately 75%, with 100% overnight storage capacity.

Next, we see output for a 500 gallon per day hot water system in Kansas City, MO. The difference in design philosophy between commercial and residential systems is evident. First, our solar fraction goal is far lower. Second, storage goals are minimized due to space and cost considerations. In summary, a cost effective commercial solar thermal installation typically seeks to meet daytime hot water needs. Major benefits of designing to a lower solar fraction with minimized storage include highest system efficiency, lowest installed cost, highest return on investment and minimized spacial impacts.

SITE ASSESSMENT AS FIRST STEP IN PROCESS

As with any mechanical system, thermal loads can be analyzed to determine the appropriately sized solar system. A site assessment is an excellet first step. A site assessment helps to determine whether the site offers proper solar orientation, whether the mechanical system can be easily adapted to accept solar energy, and to assess the characteristics of thermal loads. For small and medium commercial applications, "rules of thumb" use patterns by industrial classification often prove accurate in estimating loads. For largerapplications, SHEM recommends use of SunReports Apollo 2 monitoring to determine amount, temperatures and use patterns as part of the site assessment process.

MODULES SIMPLIFY DESIGN PROCESS

SHEM commercial systems are based on modules. Our basic commercial module is a single 120 gallon heat exchange tank couped with five 4' by 10' collectors (200 s.f.). This "five on one" configuration maximizes the

capacity of collectors and heat exchangers given pipe sizes and flow rates. (The limiting factor in this system is the 3/4" interior of the heat exchanger.) The operating characteristics of this module are well known, stable and predictable. Large systems can be created by simply ganging modules together. Manifolds with flow meters are used to separate and again consolidate cold water pre-feed flows.

Smaller commercial systems can deliver affordable, reliable savings for years to come. Below is an example of a small commercial system for a senior assisted living center. This system features three 4' * 8' Aurora collectors on an 80 gallon heat exchange tank. This system provides nearly 100% of daytime hot water need.

Hybrid systems, employing solar thermal in combination with on-demand or other types of supplemental heat, are especially beneficial where commercial boilers require replacement. Given generous solar incentives, upgrading mechanical systems to include solar thermal makes economic sense. (Note: Not all on-demand hot water units are designed for solar pre-feed. Be sure to check the manufacturer's notes. Takagi (stainless flue) and the new Eternal (Plastic Flue) on-demand systems accept solar pre-feed. Not all Bosch and Rinnai models accept solar pre-feed.)

RULES OF THUMB

Here are common sizing characteristics that provide an excellent starting point:

For a detailed example of commercial solar system design, please see the SRCC (Solar Rating and Certification Corporation) link to the ASHREAD Design Manual for Solar System Design.