What is this type of duct called on the hrv and can you tell me some examples of manufactures. I wanna look up specs and see if there is a min run length and or joints are allowed
Insulated duct. Typically when you make turns you use a standard hard 90 and pull the insulation over. I don't think anyone ever has, but we usually just use it for short HRV/ERV runs. There's definitely max run lengths for it when used for a heating/cooling unit. It can be restrictive. I couldn't name a manufacturer. I never look that close at the box when I buy it.
edit: clarification added
https://www.imperialgroup.ca/product/venting-flexible-duct/flexible-ducting/insulated/2-ply-polyester-air-duct/?query=
This manufacturer lets you join them together and has instructions for doing so on the box.
Most HRV manufacturers do not specify a maximum length, and for a principal exhaust, the Building Code allows up to 12m (39'). See OBC Article 9.32.3.4(9a).
Also, depending on where you live, and the outdoor design temperature, you may have to upgrade the intake flex from R4 to R8, when it exceeds 3m in length. See OBC Article 9.32.3.10(4) and Table 9.32.3.10.A. This is what most people get wrong where I live, in Ottawa.