Modular Home HVAC & Plumbing Design

I need a comprehensive design for duct work, HVAC sizing, and plumbing drawings for a modular home.

Requirements:
- Duct work design for central air conditioning covering the whole house
- HVAC sizing for a central air conditioning system
- Plumbing drawings

Ideal Skills & Experience:
- Experience with HVAC systems, particularly central air conditioning
- Proficiency in duct work design and plumbing layout
- Familiarity with modular home specifications and requirements
- Relevant certifications in HVAC and plumbing design