(a) The heating system must maintain a temperature of not less than 71 degrees Fahrenheit at the resident level in all resident-use areas. Auxiliary heating devices permanently installed, such as heat strips in ducts, electric ceiling-mounted heating units, and electric baseboards, may be used to augment a central heating system as approved by HHSC.
(b) The cooling system must be capable of maintaining a temperature suitable for the comfort of the residents in resident-use areas to an upper limit of 81 degrees.
(c) Air flow must be directed or adjusted so that a resident is not in direct drafts that could be harmful to the health and comfort of the resident.
(d) Unvented heating units and portable heaters are prohibited.
(e) The facility must be well ventilated through the use of windows, mechanical ventilation, or a combination of both. Rooms and areas which do not have outside windows and which are used by residents or personnel must be provided with functioning mechanical ventilation to change the air on a basis commensurate with the room usage. Air systems must provide for the induction and mixing of at least 10 percent outside fresh air into the facility unless otherwise approved by HHSC; that is, 100 percent continuous recirculation of interior air in most areas is not acceptable. When certain rooms or areas are dependent on a central air system for proper ventilation, including exhaust, that central air system fan must run continuously.
(f) Operable outside windows must be provided with insect screens. Outside doors must be self-closing to control entry of insects. All exterior doors must be effectively weather stripped.
(g) Heating and air conditioning systems must be provided with clean and effective air filters.
(h) Ducts and piping subject to surface condensation must be insulated to prevent condensation at least in areas which may affect sanitation or cause building deterioration.
(i) A comfortable temperature for residents when bathing must be provided.
(j) Heating, ventilating, and air conditioning systems must comply with the provisions of applicable National Fire Prevention Association (NFPA) standards. Ducts are to be of a Class A material (noncombustible). Combustion air for gas-fired equipment must be ducted from the exterior.
(k) Air flow must be designed to prevent cross contamination within any area where applicable, such as laundries and kitchens, as well as the system or facility as a whole.
(l) In relation to adjacent areas, a positive air pressure must be provided for clean utility rooms, clean linen rooms, and medication rooms. Conditioned supply air must be introduced into these rooms.
(m) In relation to adjacent areas, a negative air pressure must be provided for soiled utility rooms, soiled laundry rooms, bathrooms, toilets, and other odor-producing rooms. Air from these rooms must not be recirculated, but instead must be exhausted through ducts to the exterior by effective means.
(n) Facility temperature must be maintained for the comfort of residents.

Source Note: The provisions of this §554.321 adopted to be effective July 1, 1996, 21 TexReg 4408; amended to be effective August 1, 2000, 25 TexReg 6779; transferred effective January 15, 2021, as published in the Texas Register December 11, 2020, 45 TexReg 8871; amended to be effective January 2, 2022, 46 TexReg 9037