Isso se deve a uma restrição de vendas da EPA . A lógica por trás da proibição é minimizar o risco de liberar o gás refrigerante que causa o ozônio na atmosfera. Se você planeja trabalhar com sistemas HVAC com bastante frequência (por exemplo, se você gerencia muitas propriedades), então você pode tentar obter sua certificação (pode ser simples fazer algumas aulas noturnas em uma faculdade comunitária local). Para o proprietário médio, é melhor chamar um profissional, pois eles não têm apenas a certificação para obter o refrigerante, eles também têm várias ferramentas para usá-lo com segurança (manifold, bomba de vácuo, etc.).
Do link da EPA acima:
What does the sales restriction cover?
This sales restriction covers all CFC and HCFC refrigerants contained in bulk containers (such as cylinders, cans or drums). Refrigerant blends containing HCFCs (such as FRIGC FR-12, Free Zone, Hot Shot® or R-414B, GHG-X4 or R-414A, Freeze 12) are also covered under this sales restriction.
This sales restriction does not cover refrigeration and air-conditioning equipment or components containing an ozone-depleting refrigerant (such as components of residential split systems containing HCFC-22, also called R-22). Nor does the restriction cover the retail sale of air-conditioning and refrigeration appliances containing CFC or HCFC refrigerants (such as window air conditioners).
However, as of January 1, 2010, EPA banned the import and production of air-conditioning and refrigeration appliances and appliance components that are pre-charged with R-22. More information on EPA's rule banning the sale of pre-charged appliances and appliance components is found here.
EPA has previously banned the sale and distribution of refrigeration and air-conditioning appliances containing CFCs (such as R-12), under the Nonessential Products Ban.
What type of certification is required to purchase refrigerant?
The following people can buy any type of ozone-depleting refrigerant under this sales restriction (for instance, R-11, R-12, R-123, R-22), except for "small cans" containing less than 20 pounds of R-12:
- Technicians certified to service stationary refrigeration and air-conditioning equipment by a Section 608 EPA-certified testing organization; and
- Employers of a Section 608 certified technician (or the employer's authorized representative) if the employer provides the wholesaler with written evidence that he or she employs at least one properly certified technician.
The following people can buy refrigerant found acceptable for use in a motor vehicle air conditioner (MVAC), including "small cans" containing less than 20 pounds of R-12:
- Technicians certified to service motor vehicle air-conditioners by a Section 609 EPA-certified testing organization.