Magnetic filters are often pitched as the answer to keeping closed heating and cooling systems free of harmful and energy draining contaminants. Yet, they are actually not required in systems which are properly maintained.
BSRIA BG50.2013 page 51 states it best:
"Magnetic filers are similar to dirt separators but incorporate permanent magnets to trap ferromagnetic material. They are widely fitted when replacing boilers in domestic heating systems, mainly to protect the new boiler heat exchanger and pump seals from magnetite that has been previously formed in the old boiler and radiators.
It goes on to say:
"In principle, magnetic filtration should not be advantageous on a properly maintained system with low suspended solids."
Let's take a closer look at the types of fouling in closed systems and wether they contaminants are attracted to magnets:
- Iron hematite (red iron oxide) - NO
- Iron magnetite (black iron oxide) - YES
- Copper oxides - NO
- Aluminium oxides - NO
- Scale - NO
- Organic materials - NO
- Microbiological debris - NO
- Biofilm particles - NO
So, out of eight types of fouling, only one type - iron magnetite - is attracted to magnets.
On the contrary, correctly specified physical filters will remove ALL of these types of fouling.
Offering little advantage (and many disadvantages, including higher expense and health and safety considerations), why fit magnets?
Physical filters are clearly the most beneficial choice for closed systems where suspended solids are of concern.
At DosaFil, our devices combine side stream filtration with automatic air removal and chemical dosing. To find out more about our devices, please get in touch.